Multi-source wide-area power distribution network hierarchical timing method, device, system and chip

Abstract

The present disclosure relates to the field of power distribution and communication technology, and specifically to a hierarchical timing method, device, system and chip for a multi-source wide-area power distribution network. The present disclosure innovatively proposes the concept of a multi-source fusion node, which can support and fuse time information from multiple different timing sources, and perform timing on a designated node based on the fused timing time. When obtaining the fused timing time, first determine a first intermediate value set based on multiple timing times. When there are multiple first intermediate value sets, further calculate multiple second intermediate values ​​based on the credibility of the timing source or the deviation value between the timing times, and select the optimal second intermediate value as the timing reference through preset rules. After completing the timing of the designated node, hierarchical timing is performed on other nodes based on the nodes that have been timed. This improves the accuracy and efficiency of time synchronization in the multi-source wide-area power distribution network, and ensures the time accuracy and synchronization of the power wide-area power distribution business.

Description

Technical Field

[0001] The present disclosure relates to the field of power distribution and communication technology, and in particular to a multi-source wide-area power distribution network hierarchical timing method, device, system and chip. Background Art

[0002] The power system is the most critical infrastructure and is vital to the national economy and security. The power system is geographically dispersed. To achieve continuous monitoring of the grid operation status, rapid identification and location of faults, timely response and repair, etc., it is necessary to easily obtain standard time on a large scale to maintain the time synchronization of the power system.

[0003] The efficient interaction, safe and stable operation of power distribution and utilization cannot be separated from various automatic monitoring equipment, and providing a unified time base for automatic control equipment can ensure the validity of measurement data. Strict time synchronization is required in the synchronous collection of power distribution and utilization information, differential protection, fault monitoring and processing, time-based billing and other services. Time calibration and synchronization are the core foundation for realizing efficient data collection, intelligent control, fault warning and remote management. Each node in the power distribution and utilization network not only needs to accurately record power consumption information, but also needs to work together based on a unified time base to ensure the accuracy and real-time nature of data analysis.

[0004] The time synchronization of power distribution network equipment generally includes two stages: the first stage is the time synchronization of the power distribution terminal, in which the power distribution terminal obtains accurate time reference through clock sources such as satellites and the Internet; the second stage is the time calibration of the substation, in which the power distribution terminal broadcasts the time synchronization to meters, switches and other equipment in the substation through the local communication network, thereby achieving the purpose of accurate synchronization of the clocks of the power distribution network equipment in the entire area.

[0005] For the timing of power distribution and utilization terminals:

[0006] High-precision and reliable timing sources are the basis and guarantee for the timing of power distribution and utilization terminals. At present, the commonly used timing methods in power systems mainly include: satellite timing (such as Beidou, GPS, low-orbit satellite timing), ground network timing (such as network time protocol NTP, precision time protocol PTP), radio wave timing (such as long wave timing, short wave timing) and 5G communication timing.

[0007] Among them, the space-based timing based on navigation and positioning satellite systems such as Beidou and GPS has high accuracy and is not restricted by geographical location, but there are problems such as lack of indoor coverage, obstruction in densely populated urban areas and high maintenance costs; ground network timing is mainly broadcast through Ethernet, cellular networks, etc., which is easily affected by network delays and error accumulation; radio wave timing has a long propagation distance and can cover a larger area, but compared with satellite timing, the timing accuracy is lower and it is easily affected by weather conditions (such as ionospheric disturbances) and electromagnetic interference. The high reliability and ultra-low latency characteristics unique to 5G communication timing make it an ideal way for power time synchronization and transmission, providing the possibility for the construction of a high-precision time network. The time synchronization error between 5G base stations in my country is within 1.5 µs, but when using 5G air interface technology to time the distribution and use terminals, there are timing accuracy errors caused by time division duplex communication, inconsistent uplink and downlink rates, and unequal delays. At the same time, 5G air interface wireless transmission may be affected by factors such as signal-to-noise ratio, transmission bandwidth, and base station side processing, resulting in large air interface delay jitter, which in turn affects timing accuracy. Generally speaking, the time synchronization accuracy of power distribution and utilization terminals using 5G air interface technology is around ±100ms, which cannot meet the high-precision clock requirements of power distribution and utilization services.

[0008] It can be seen from this that the existing single timing method has its own shortcomings, and its wide-area availability and adaptability are difficult to meet the high-precision timing and synchronization needs of massive power distribution and power consumption terminals.

[0009] For time calibration in Taiwan area:

[0010] In terms of time calibration and synchronization from the substation terminal to the meter equipment node, since power lines are the most popular and widely covered physical media, using power lines to transmit data information is extremely convenient. Without rewiring, all electrical appliances connected to the power lines can form a communication network for information exchange and communication. Therefore, using power lines as a communication medium for time calibration has become an economical and efficient solution.

[0011] At present, the published high-speed power line carrier and high-speed dual-mode communication protocols stipulate that all nodes in the substation area support the terminal to calibrate the time of the electric energy meter. When calibrating the time, you can select a device (such as the central coordination node CCO) as the master node, and set its clock as the reference time, and other devices (such as the proxy coordination node PCO and the site STA) as slave nodes. The master node broadcasts the time calibration information (such as timestamps, time signals, etc.) to the slave node regularly or according to demand. The slave node receives the time calibration information and adjusts its own clock according to the received information to achieve time synchronization with the master node.

[0012] Although power line carrier technology is popular due to its high popularity and wide coverage, it still faces many challenges in practical applications. First, power line carrier signals are susceptible to electromagnetic interference during transmission, such as power load changes, line aging, harmonic interference, etc. These factors will cause signal attenuation and distortion, thereby affecting communication quality and time synchronization accuracy. Secondly, due to the large range of the station area, when the slave node performs time synchronization based on the time synchronization information of the master node, the time synchronization signal needs to be forwarded step by step through multiple relay nodes during the transmission process, which not only increases the communication delay, but also may cause the error accumulation in each forwarding process, resulting in a significant increase in the terminal node time synchronization deviation.

[0013] How to improve the timing accuracy, synchronization and reliability of the power distribution network, thereby improving the reliability and stability of the entire power distribution network, is an urgent problem to be solved. Summary of the invention

[0014] In order to solve the problems in the related art, the embodiments of the present disclosure provide a multi-source wide-area power distribution network hierarchical timing method, device, system and chip.

[0015] In a first aspect, a multi-source wide-area power distribution network hierarchical timing method is provided in an embodiment of the present disclosure, wherein the power distribution network includes multiple nodes, at least one of which is a multi-source fusion node, and the multi-source fusion node supports fusion timing of multiple different timing sources; the power distribution network also includes a terminal wireless device, and the terminal wireless device is connected to the node in the power distribution network; the timing method includes:

[0016] The multi-source fusion node is used to calibrate the time of a designated node in the power distribution network in the following manner, wherein the designated node includes the multi-source fusion node or a node other than the multi-source fusion node:

[0017] Obtain multiple timing times from multiple different timing sources;

[0018] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0019] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0020] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set;

[0021] After the designated node completes the time calibration, the other nodes in the power distribution network are time-calibrated based on the designated node;

[0022] After the nodes in the power distribution network complete time synchronization, the time synchronization period of the terminal wireless device connected to the node is obtained according to the time error coefficient and the maximum time synchronization tolerance threshold of the terminal wireless device; the terminal wireless device is time synchronized according to the time synchronization period.

[0023] According to an embodiment of the present disclosure, the power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The nodes in the power distribution network are connected through power line carrier communication links and / or wireless communication links; the multiple layers of nodes in the power distribution network include master nodes and slave nodes. The 0th layer node in the power distribution network is the master node, and the other layer nodes except the 0th layer node are slave nodes. The master node and the slave node are both provided with a zero-crossing detection circuit. The upper layer node of the slave node includes: the master node, the master node is a designated node in the power distribution network, or a node that is timed by a designated node in the power distribution network, and the time synchronizing other nodes in the power distribution network based on the designated node includes:

[0024] After the upper node of the slave node completes time calibration, a time calibration beacon sent by the upper node is received, wherein the time calibration beacon contains time calibration information, and the time calibration information includes: a time value of the sending time of the time calibration beacon, and an NTB time difference between the sending time and the first zero-crossing time of the phase line where the upper node sending the time calibration beacon is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the upper node sending the time calibration beacon;

[0025] Obtaining the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located;

[0026] The slave node is timed according to the time calibration information in the received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located.

[0027] According to an embodiment of the present disclosure, the power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The nodes in the power distribution network are connected via power line carrier communication links and / or wireless communication links. The multiple layers of nodes in the power distribution network include time calibration nodes and time-calibrated nodes. The time calibration nodes and time-calibrated nodes are respectively in the same layer, adjacent layers or across layers. The time calibration nodes include: designated nodes in the power distribution network, or nodes that are time-calibrated through designated nodes in the power distribution network. The time calibration of other nodes in the power distribution network based on the designated nodes includes:

[0028] Acquire first time synchronization information, where the first time synchronization information is a local clock timing value of the time-synchronized node acquired by the time-synchronized node at a reference time or a time having a preset relationship with the reference time;

[0029] Acquire second time synchronization information, where the second time synchronization information is a local clock timing value of the time synchronization node acquired by the time synchronization node at the reference time after completing the time synchronization;

[0030] Performing time calibration on the time-calibrated node based on the first time calibration information and the second time calibration information;

[0031] Among them, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: the rising edge zero-crossing time and / or the falling edge zero-crossing time.

[0032] According to an embodiment of the present disclosure, the step of acquiring the timing period of the terminal wireless device connected to the node according to the time error coefficient and the maximum time synchronization tolerance threshold of the terminal wireless device includes:

[0033] Obtain the time error coefficient of the terminal wireless device to form a time error coefficient set , recorded as: ; Where n represents the number of the terminal wireless devices, the time error coefficient of the i-th terminal wireless device is the time interval between two time calibrations performed by the node on the i-th terminal wireless device , and the internal clock time error of the ith terminal wireless device after the two calibrations , calculated by the following formula:

[0034] ,in, , is the internal clock time of the i-th terminal wireless device after the node performs the first time calibration on the i-th terminal wireless device, The internal clock time of the i-th terminal wireless device after the node performs the second time calibration on the i-th terminal wireless device;

[0035] Acquire a maximum time synchronization tolerance threshold of the terminal wireless device;

[0036] Calculate the maximum timing cycle of the terminal wireless device according to the maximum time synchronization tolerance threshold and the time error coefficient set to form a maximum timing cycle set , where the maximum timing period of the i-th terminal wireless device is , is the maximum time synchronization tolerance threshold of the i-th terminal wireless device;

[0037] Time slot allocation is performed according to the maximum timing cycle of the terminal wireless device to obtain the timing cycle of the terminal wireless device.

[0038] According to an embodiment of the present disclosure, the step of calibrating the time of the terminal wireless device according to the time calibration period includes:

[0039] Determine the optimization goal:

[0040]

[0041] in, The power consumption generated by the node calibrating the terminal wireless device; The channel time occupied by the node for calibrating the terminal wireless device, is a threshold of the channel occupation ratio for the node to perform time synchronization on the terminal wireless device, is the time calibration period of the i-th terminal wireless device;

[0042] Optimize the time synchronization period of the terminal wireless device according to the optimization target ;

[0043] The terminal wireless device is time-calibrated according to the optimized time-calibration cycle.

[0044] In a second aspect, an embodiment of the present disclosure provides a timing method for a multi-source fusion node, wherein the multi-source fusion node supports fusion timing of multiple different timing sources, and the timing method includes:

[0045] Obtain multiple timing times from multiple different timing sources;

[0046] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0047] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; the first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of a designated node, and the designated node includes the multi-source fusion node or a node other than the multi-source fusion node;

[0048] When the first intermediate value set is one, there are one or more elements in the first intermediate value set, and the first intermediate value set is used to calibrate the time of the designated node.

[0049] According to an embodiment of the present disclosure, the acquiring of multiple timing times respectively from multiple different timing sources includes:

[0050] Acquire a preferred timing source set, wherein the preferred timing source set includes a plurality of different preferred timing sources, and the preferred timing source is a timing source that satisfies an evaluation condition and is screened out from the plurality of different timing sources by evaluating them;

[0051] Based on the preferred timing source set, multiple timing times respectively from the multiple different preferred timing sources are acquired.

[0052] According to an embodiment of the present disclosure, the preferred timing source set is determined according to the following method:

[0053] Acquire timing source evaluation indicators of the multiple different timing sources, wherein the timing source evaluation indicators are used to evaluate the availability of the timing sources;

[0054] Constructing a utility function according to the timing source evaluation index, and using the utility function to calculate the utility values ​​of the multiple different timing sources;

[0055] The multiple different timing sources are sorted from high to low according to the utility values, and according to the sorting result, a preset number of timing sources are selected to form the preferred timing source set.

[0056] According to an embodiment of the present disclosure, the timing source evaluation index includes: timing signal quality, timing accuracy, timing credibility and long-term availability; constructing a utility function according to the timing source evaluation index, and using the utility function to calculate the utility values ​​of the multiple different timing sources, including:

[0057] Obtain the timing signal strength and / or the timing signal signal-to-noise ratio and / or the timing signal jitter rate of each timing source, and obtain the timing signal quality score of each timing source according to the timing signal strength and / or the timing signal signal-to-noise ratio and / or the timing signal jitter rate of each timing source;

[0058] Obtain the timing accuracy of each timing source, and obtain the timing accuracy score of each timing source according to the timing accuracy of each timing source;

[0059] By comparing the synchronization of the timing time of each timing source with the time pulse signal, the timing credibility of each timing source is judged, including: monitoring the frequency of the time pulse signal of each timing source, calculating the pulse deviation of each timing source, and obtaining the timing credibility score of each timing source according to the pulse deviation of each timing source;

[0060] Counting the available time of each timing source within a preset time period, obtaining the long-term availability of each timing source according to the available time of each timing source within the preset time period, and obtaining the score of the long-term availability of each timing source according to the long-term availability of each timing source;

[0061] The utility value of each timing source is calculated according to the following utility function constructed based on the score of the timing signal quality, the score of the timing accuracy, the score of the timing credibility and the score of the long-term availability:

[0062] ;

[0063] in, represents the utility value of the i-th timing source, represents the score of the timing signal quality of the i-th timing source, The weight representing the quality of the timing signal of the i-th timing source; represents the score of the timing accuracy of the i-th timing source, Represents the weight of the timing accuracy of the i-th timing source; Indicates the score of the timing reliability of the i-th timing source; Represents the weight of the timing credibility of the i-th timing source; represents the score of the long-term availability of the i-th timing source, Represents the weight of the long-term availability of the i-th timing source.

[0064] According to an embodiment of the present disclosure, the step of obtaining timing source evaluation indicators of the plurality of different timing sources includes:

[0065] Obtain the current timing mode, where the current timing mode includes: a conventional timing mode, an emergency timing mode, a high-precision timing mode, a regional timing mode, and a backup timing mode;

[0066] Obtain timing source evaluation indicators of the multiple different timing sources in the current timing mode.

[0067] According to an embodiment of the present disclosure, determining a first intermediate value set according to the multiple timing times includes:

[0068] Obtaining the timing accuracy and comprehensive credibility of each timing source; wherein the comprehensive credibility is determined based on the stability parameter, accuracy parameter and environmental factor of the corresponding timing source;

[0069] Determine the timing accuracy range of each timing source according to the timing accuracy of each timing source;

[0070] Determine the trust density of each timing source according to the timing accuracy interval and the comprehensive trustworthiness of each timing source, wherein the trust density is the comprehensive trustworthiness divided by the length of the timing accuracy interval;

[0071] Normalize the trust density of each timing source;

[0072] The multi-source fused timing time is calculated according to the timing time of each timing source and the credible density of each timing source after normalization, and the multi-source fused timing time forms the first intermediate value set.

[0073] According to an embodiment of the present disclosure, the method of calculating the multi-source fusion timing time according to the timing time of each timing source and the credible density of each timing source after normalization includes:

[0074] The multi-source fusion timing time is calculated using the following formula: :

[0075] ;

[0076] in, is the timing time of the i-th timing source; is the normalized credible density of the i-th timing source, =1, n is the total number of timing sources;

[0077] The first intermediate value set is used to calibrate the time of the designated node in the following manner, including:

[0078] The multi-source fusion timing is used to calibrate the time of the designated node.

[0079] According to an embodiment of the present disclosure, determining one or more first intermediate value sets according to the multiple timing times includes:

[0080] Obtain the timing accuracy of each preferred timing source;

[0081] Determine the timing range of each preferred timing source according to the timing accuracy and timing time of each preferred timing source;

[0082] The intersection interval formed by the intersection of each timing range interval is determined by comparing the timing range intervals of each preferred timing source; wherein the two interval endpoints of the intersection interval form the first intermediate value set.

[0083] According to an embodiment of the present disclosure, when the first intermediate value set is one, the first intermediate value set is used to calibrate the time of the designated node in the following manner, including:

[0084] Taking the average value of the two interval endpoints in the first intermediate value set as the multi-source fusion timing time, and using the multi-source fusion timing time to calibrate the time of the designated node;

[0085] When there are multiple first intermediate value sets, determining multiple corresponding second intermediate values ​​according to the multiple first intermediate value sets respectively includes:

[0086] The second intermediate value corresponding to each first intermediate value set is determined as follows:

[0087] Determine the timing accuracy interval of each preferred timing source corresponding to the first intermediate value set according to the timing accuracy of each preferred timing source corresponding to the first intermediate value set;

[0088] Determine the credibility density of each preferred timing source corresponding to the first intermediate value set according to the credibility and timing precision interval of each preferred timing source corresponding to the first intermediate value set, wherein the credibility density is the credibility divided by the length of the timing precision interval;

[0089] The second intermediate value corresponding to the first intermediate value set is determined based on the maximum of the credible densities of the preferred timing sources corresponding to the first intermediate value set and the length of the intersection interval corresponding to the first intermediate value set, and the second intermediate value is the product of the maximum and the length of the intersection interval.

[0090] According to an embodiment of the present disclosure, the step of selecting a preferred second intermediate value from a plurality of second intermediate values ​​according to a preset rule includes:

[0091] selecting a maximum of the plurality of second intermediate values ​​as the preferred second intermediate value;

[0092] The first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of the designated node in the following manner, including:

[0093] The average value of two interval endpoints in the first intermediate value set corresponding to the preferred second intermediate value is used as the multi-source fusion timing time, and the multi-source fusion timing time is used to calibrate the time of the designated node.

[0094] According to an embodiment of the present disclosure, the time synchronization method further includes:

[0095] Monitoring the availability of each preferred timing source in the preferred timing source set;

[0096] When the number of available preferred timing sources in the preferred timing source set does not meet a preset number threshold, the preferred timing source set is re-determined.

[0097] According to an embodiment of the present disclosure, monitoring the availability of each preferred timing source in the preferred timing source set includes:

[0098] The local clock error of the multi-source fusion node after the time calibration is estimated by least squares to generate a first error compensation parameter and the second error compensation parameter ;

[0099] According to the running values ​​corresponding to the i-2, i-1 and i moments of the local clock of the multi-source fusion node, And the first error compensation parameter and the second error compensation parameter Get the time of the local clock i of the multi-source fusion node for prediction compensation ,in,

[0100] ;

[0101] The timing time of each preferred timing source in the preferred timing source set at the time i is obtained, and is recorded as: ; n represents the number of preferred timing sources in the preferred timing source set;

[0102] The error between the timing time of each preferred timing source at time i in the preferred timing source set and the time of the local clock of the multi-source fusion node at time i of the prediction compensation is calculated respectively, wherein the timing time of the jth preferred timing source at time i is The error between the time at the local clock i of the multi-source fusion node compensated by the prediction Denoted as:

[0103] ;

[0104] It is determined whether each error is greater than a set error threshold. If so, it is determined that the corresponding preferred timing source is not available, and the corresponding preferred timing source is deleted from the preferred timing source set.

[0105] According to an embodiment of the present disclosure, the multi-source fusion node is in a first mobile communication network, and the multiple different timing sources supported by the multi-source fusion node include a mobile communication air interface timing source and a preset reference timing source, and the acquiring of multiple timing times respectively from the multiple different timing sources includes:

[0106] Obtaining the timing time of n historical moments corresponding to the preset reference timing source to form a first timing time sequence; wherein n is a positive integer greater than a preset threshold;

[0107] Obtaining the timing time of the mobile communication air interface timing source corresponding to the n historical moments to form a second timing time sequence;

[0108] The determining one or more first intermediate value sets according to the multiple timing times includes:

[0109] Calculate the timing time deviation value between the first timing time sequence and the second timing time sequence corresponding to each historical moment to form an original timing time deviation value sequence;

[0110] Based on each of the preset multiple window length values, respectively, the original timing time deviation value sequence is subjected to moving average filtering processing to generate multiple filtered timing time deviation value sequences corresponding to the multiple window length values, wherein the filtered timing time deviation value sequences form the first intermediate value set;

[0111] Wherein, the filtered timing time deviation value sequence corresponding to the window length value is determined in the following manner:

[0112] ,

[0113] in, represents the ith sequence value in the filtered timing time deviation value sequence, m represents the window length value, Represents the ijth sequence value in the original timing time deviation value sequence.

[0114] According to an embodiment of the present disclosure, the determining corresponding multiple second intermediate values ​​according to the multiple first intermediate value sets respectively includes:

[0115] The second intermediate value corresponding to each first intermediate value set is determined as follows:

[0116] The Pearson coefficient p is calculated according to the original timing time deviation value sequence and the filtered timing time deviation value sequence corresponding to the first intermediate value set. The Pearson coefficient p is the second intermediate value corresponding to the first intermediate value set. The Pearson coefficient p is expressed by the following formula:

[0117] ,

[0118] in, It is represented as the i-th sequence value in the original timing time deviation value sequence, and are respectively the means of the original timing time deviation value sequence and the filtered timing time deviation value sequence, is the covariance of the original timing time deviation value sequence and the filtered timing time deviation value sequence, and are respectively the standard deviations of the original timing time deviation value sequence and the filtered timing time deviation value sequence.

[0119] According to an embodiment of the present disclosure, the selecting a preferred second intermediate value from a plurality of second intermediate values ​​according to a preset rule includes:

[0120] The multiple Pearson coefficients corresponding to the multiple window length values ​​are compared with the preset Pearson coefficient threshold value respectively, and the Pearson coefficient among the multiple Pearson coefficients that is closest to the preset Pearson coefficient threshold value is used as the preferred second intermediate value.

[0121] According to an embodiment of the present disclosure, the first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of the designated node in the following manner, including:

[0122] The timing time optimization parameter is determined according to the nth sequence value in the filtered timing time deviation value sequence corresponding to the preferred second intermediate value and the air interface transmission delay corresponding to the nth historical moment of the mobile communication air interface timing source, wherein the timing time optimization parameter Use the following formula to express it:

[0123] ,

[0124] in, is the nth filtered timing deviation sequence value, is the air interface transmission delay corresponding to the nth historical moment;

[0125] The timing time optimization parameter is used to correct the timing time of the mobile communication air interface timing source, and the corrected timing time of the mobile communication air interface timing source is used to calibrate the time of the designated node.

[0126] According to an embodiment of the present disclosure, the using the timing time optimization parameter to correct the timing time of the mobile communication air interface timing source includes:

[0127] Obtain the reference time and the time advance TA sent by the mobile communication air interface timing source;

[0128] Determine the current air interface transmission delay according to the time advance TA;

[0129] The sum of the current air interface transmission delay and the reference time sent by the mobile communication air interface timing source is used as the timing time of the mobile communication air interface timing source;

[0130] The timing time of the mobile communication air interface timing source is corrected using the following formula based on the timing time optimization parameter:

[0131] ,

[0132] in, is the corrected timing time of the mobile communication air interface timing source, is the reference time sent by the mobile communication air interface timing source, is the current air interface transmission delay.

[0133] According to an embodiment of the present disclosure, the designated node includes: a mobile communication timing node, the mobile communication timing node is in the first mobile communication network or the second mobile communication network, and the mobile communication timing node supports the mobile communication air interface timing source; the use of the timing time optimization parameter to correct the timing time of the mobile communication air interface timing source includes:

[0134] Sending the timing time optimization parameter to the mobile communication base station of the first mobile communication network, so that the mobile communication base station in the first mobile communication network carries the timing time optimization parameter to perform timing on the mobile communication timing node in the first mobile communication network, so that the mobile communication timing node in the first mobile communication network uses the timing time optimization parameter to correct the timing time of the mobile communication air interface timing source;

[0135] And / or, so that the mobile communication base station of the first mobile communication network transmits the timing time optimization parameters back to the mobile communication access layer network, so that the mobile communication access layer network sends the timing time optimization parameters to the mobile communication base station in the second mobile communication network, so that the mobile communication base station in the second mobile communication network carries the timing time optimization parameters to time the mobile communication timing nodes in the second mobile communication network, so that the mobile communication timing nodes in the second mobile communication network use the timing time optimization parameters to correct the timing time of the mobile communication air interface timing source.

[0136] According to an embodiment of the present disclosure, when the first mobile communication network includes multiple multi-source fusion nodes, the timing method further includes:

[0137] Sending the multiple timing time optimization parameters respectively determined by the multiple multi-source fusion nodes to the mobile communication base station in the first mobile communication network, so that the mobile communication base station in the first mobile communication network determines the final timing time optimization parameter according to the multiple timing time optimization parameters;

[0138] Receive multiple timing time optimization parameters corresponding to the multiple multi-source fusion nodes sent by the mobile communication base station of the first mobile communication network; use the multiple timing time optimization parameters to correct the timing time of the mobile communication air interface timing source respectively to obtain the corresponding multiple corrected timing time of the mobile communication air interface timing source, calculate the difference between the multiple corrected timing time of the mobile communication air interface timing source and the timing time of the preset reference timing source respectively, obtain multiple errors corresponding to the multiple timing time optimization parameters, and send the multiple errors corresponding to the multiple timing time optimization parameters to the mobile communication base station of the first mobile communication network, so that after the mobile communication base station of the first mobile communication network receives the multiple errors corresponding to the multiple timing time optimization parameters sent by each multi-source fusion node, it weighted averages the errors calculated by the multiple multi-source fusion nodes using the same timing time optimization parameters to obtain multiple weighted average results, and sends the timing time optimization parameter of the multi-source fusion node corresponding to the smallest of the multiple weighted average results as the final timing time optimization parameter to the multiple multi-source fusion nodes;

[0139] The final timing time optimization parameter sent by the mobile communication base station of the first mobile communication network is received, so as to use the final timing time optimization parameter to correct the timing time of the mobile communication air interface timing source.

[0140] According to an embodiment of the present disclosure, the multi-source fusion node is in a first mobile communication network, the multiple different timing sources supported by the multi-source fusion node include a mobile communication air interface timing source and a preset reference timing source, the mobile communication air interface timing source includes a cellular communication air interface timing and a direct communication timing, the first mobile communication network also includes a non-cellular timing node, the non-cellular timing node does not support cellular communication air interface timing and supports direct communication timing, the designated node is connected to the non-cellular timing node via a direct communication link, and the timing method also includes:

[0141] After the designated node is timed, the delay measurement information is interacted with the non-cellular timing node through the Precision Time Protocol (PTP), so that the non-cellular timing node performs time synchronization based on the designated node.

[0142] In a third aspect, an embodiment of the present disclosure provides a time synchronization method for a power distribution network, wherein the power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, wherein the 0th layer node is a master node, and other layer nodes except the 0th layer node are slave nodes, wherein the slave node is connected to the upper layer node via a power line carrier communication link and / or a wireless communication link, and the master node and the slave node are both provided with a zero-crossing detection circuit, and the time synchronization method is applied to the slave node in the power distribution network, and the time synchronization method includes:

[0143] After the upper node of the slave node completes time calibration, a time calibration beacon sent by the upper node is received, wherein the time calibration beacon contains time calibration information, and the time calibration information includes: a time value of the sending time of the time calibration beacon, and an NTB time difference between the sending time and the first zero-crossing time of the phase line where the upper node sending the time calibration beacon is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the upper node sending the time calibration beacon;

[0144] Obtaining the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located;

[0145] Performing time calibration on the slave node according to the time calibration information in the received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located;

[0146] The upper node of the slave node includes: the master node, the master node is a designated node in the power distribution network, or a node that performs time synchronization through the designated node, the designated node includes a multi-source fusion node or a node other than the multi-source fusion node, the multi-source fusion node supports fusion timing of multiple different timing sources, and the designated node in the power distribution network is synchronized in the following manner through the multi-source fusion node:

[0147] Obtain multiple timing times from multiple different timing sources;

[0148] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0149] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0150] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0151] According to an embodiment of the present disclosure:

[0152] The first zero-crossing time and the second zero-crossing time are the same zero-crossing time; or

[0153] There is a preset relationship between the first zero-crossing time and the second zero-crossing time.

[0154] According to an embodiment of the present disclosure, the slave node is also connected to the lower node via a power line carrier communication link and / or a wireless communication link, and the timing method further includes:

[0155] After the slave node completes the time calibration, it sends a time calibration beacon to the lower-layer node, so that the lower-layer node calibrates the local time according to the time calibration information in the received time calibration beacon.

[0156] According to an embodiment of the present disclosure, the time calibration of the slave node according to the time calibration information in the received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located includes:

[0157] Obtaining a time calibration NTB time difference according to the NTB time difference in the time calibration information, wherein the time calibration NTB time difference corresponds to the phase line where the slave node is located;

[0158] Calculate the time calibration beacon transmission delay time according to the time calibration NTB time difference and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located;

[0159] Calculate the calibration time corresponding to the reception time of the time calibration beacon according to the transmission delay time of the time calibration beacon and the time value of the sending time in the calibration information;

[0160] The time is calibrated using the calibration time corresponding to the reception time of the time calibration beacon.

[0161] According to an embodiment of the present disclosure, the NTB time difference includes: any one or more of a first NTB time difference, a second NTB time difference, and a third NTB time difference; the first NTB time difference, the second NTB time difference, and the third NTB time difference correspond to three different phase lines respectively, and the obtaining of the time calibration NTB time difference according to the NTB time difference in the time calibration information includes:

[0162] When the NTB time difference in the timing information includes the first NTB time difference, the second NTB time difference and the third NTB time difference, the NTB time difference in the timing information corresponding to the phase line where the slave node is located is used as the timing NTB time difference;

[0163] When the NTB time difference in the timing information is any one of the first NTB time difference, the second NTB time difference, and the third NTB time difference, and the upper node that sends the time calibration beacon and the slave node are in-phase nodes, the NTB time difference in the timing information is used as the timing NTB time difference; when the NTB time difference in the timing information is any one of the first NTB time difference, the second NTB time difference, and the third NTB time difference, and the upper node that sends the time calibration beacon and the slave node are not in-phase nodes, obtain two NTB time differences in the time calibration beacon sent by the master node that correspond to the phase line where the slave node is located and the phase line where the upper node that sends the time calibration beacon is located, obtain the difference between the two NTB time differences, and subtract the difference from the NTB time difference in the timing information to obtain the timing NTB time difference.

[0164] According to an embodiment of the present disclosure, the time calibration beacon transmission delay time is calculated using the following formula:

[0165] ;

[0166] The calibration time corresponding to the reception time of the time calibration beacon is calculated using the following formula:

[0167] ;

[0168] in, represents a calibration time corresponding to the reception moment of the time calibration beacon; Indicates the transmission delay time of the time calibration beacon; The time value representing the sending time in the time calibration information; represents the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located; is the power frequency cycle; n is the number of power frequency cycles spanned during the transmission of the time calibration beacon, n≥0, It is the time difference of the time calibration NTB.

[0169] In a fourth aspect, a time synchronization method for a power distribution network is provided in an embodiment of the present disclosure. The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, wherein the 0th layer node is a master node, and other layer nodes except the 0th layer node are slave nodes. The master node is connected to the lower layer slave node through a power line carrier communication link and / or a wireless communication link, and the master node and the slave node are both provided with a zero-crossing detection circuit. The time synchronization method is applied to the master node in the power distribution network, and the time synchronization method includes:

[0170] After completing the time calibration, a time calibration beacon is sent to the lower-layer slave node to realize the time calibration of the lower-layer slave node; the time calibration beacon contains the time calibration information, so that the lower-layer slave node can calibrate the local time according to the time calibration information in the time calibration beacon and the NTB time difference between the receiving time of the time calibration beacon and the zero-crossing time of the phase line where the lower-layer slave node is located; wherein the time calibration information includes: the time value of the sending time of the time calibration beacon, and the NTB time difference between the sending time and the zero-crossing time of the phase line where the master node is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the master node;

[0171] The master node is a designated node in the power distribution network, or a node that is timed by the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to sync the designated node in the power distribution network in the following manner:

[0172] Obtain multiple timing times from multiple different timing sources;

[0173] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0174] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0175] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0176] In a fifth aspect, an embodiment of the present disclosure provides a time synchronization method for a power distribution network, wherein the power distribution network adopts a layered networking mode and includes multiple layers of nodes, wherein the time synchronization node and the time synchronized node are respectively in the same layer, adjacent layers or across layers, and are connected via a power line carrier communication link and / or a wireless communication link, wherein the time synchronization method is applied to the time synchronized node in the power distribution network, and the time synchronization method includes:

[0177] Acquire first time synchronization information, where the first time synchronization information is a local clock timing value of the time-synchronized node acquired by the time-synchronized node at a reference time or a time having a preset relationship with the reference time;

[0178] Acquire second time synchronization information, where the second time synchronization information is a local clock timing value of the time synchronization node acquired by the time synchronization node at the reference time after completing the time synchronization;

[0179] Performing time calibration on the time-calibrated node based on the first time calibration information and the second time calibration information;

[0180] Wherein, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: a rising edge zero-crossing time and / or a falling edge zero-crossing time;

[0181] The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner:

[0182] Obtain multiple timing times from multiple different timing sources;

[0183] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0184] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0185] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0186] According to an embodiment of the present disclosure, when the reference time is a specified zero-crossing time, the first time calibration information is the time value recorded by the local clock at one or more specified zero-crossing times on the phase line where the time calibration node is located; the second time calibration information is the time value recorded by the local clock at one or more specified zero-crossing times on the phase line where the time calibration node is located;

[0187] When the reference time is the time when the node being calibrated and the timing node simultaneously receive the reference beacon sent by the reference node, the physical layers of the timing node, the node being calibrated and the reference node have the same transmission and reception delay under the same communication mode, and the first timing information and the second timing information are respectively the time values ​​recorded using the local clock when the node being calibrated and the timing node simultaneously receive the reference beacon sent by the same reference node.

[0188] According to an embodiment of the present disclosure, the obtaining of the second timing information includes:

[0189] Receive a time calibration beacon sent by the timing node, wherein the time calibration beacon carries the second timing information; and obtain the second timing information from the time calibration beacon.

[0190] According to an embodiment of the present disclosure, after receiving the time calibration beacon sent by the timing node, the timing method further includes:

[0191] Recording a calibration time value, where the calibration time value is a time value measured by the local clock of the time-calibrated node corresponding to the moment of receiving the time calibration beacon;

[0192] The step of timing the node to be timed based on the first timing information and the second timing information includes: timing the node to be timed based on the first timing information, the second timing information and the calibration time scale value using the following formula:

[0193] ;

[0194] in, represents the first time synchronization information, represents the second timing information, represents the calibration time scale value, Represents the local clock timing value of the node being calibrated after the calibration time value is calibrated.

[0195] According to an embodiment of the present disclosure, when time calibration beacons sent by multiple timing nodes are received, the timing information in the time calibration beacon sent by the timing node that has the closest communication distance to the node being timed, has better communication quality, or has the lowest level among the multiple timing nodes is selected as the second timing information.

[0196] According to an embodiment of the present disclosure, if time calibration beacons sent by multiple timing nodes are received, the multiple timing nodes include: a first timing node and a second timing node;

[0197] The step of calibrating the time of the node to be timed based on the first time calibration information and the second time calibration information includes:

[0198] When the first timing node has the shortest communication distance or the lowest level with the time-corrected node relative to the second timing node, the time-corrected node is timed based on the second timing information of the first timing node and the first timing information;

[0199] When the first timing node and the second timing node are at the same level, signal quality indicators of the first timing node and the second timing node when communicating with the source node of the upper level are respectively obtained, the corresponding communication quality is evaluated according to the signal quality indicators, and the timing node that meets the evaluation conditions among the first timing node and the second timing node is selected according to the communication quality evaluation result; the timing of the timing node being calibrated is performed based on the second timing information of the timing node that meets the evaluation conditions and the first timing information.

[0200] According to an embodiment of the present disclosure, the time synchronization method further includes:

[0201] The local clock error of the node being timed after multiple time calibrations is estimated by least squares to generate a first error compensation parameter. and the second error compensation parameter ;

[0202] According to the running values ​​corresponding to the i-2, i-1 and i moments of the local clock of the node being timed, And the first error compensation parameter and the second error compensation parameter Determine the time at time i of the local clock of the node being timed to be predicted and compensated ,in,

[0203] .

[0204] According to an embodiment of the present disclosure, when the reference time is a specified zero-crossing time, the time calibrating the time-calibrated node based on the first time calibration information and the second time calibration information includes:

[0205] According to the first time calibration information and the second time calibration information, obtaining the time deviation recorded by the local clock at the designated zero-crossing moment in the same voltage waveform cycle of the same phase line between the time calibration node and the time-calibrated node;

[0206] The time deviation is used to calibrate the time of the node being timed.

[0207] According to an embodiment of the present disclosure, the step of obtaining the time deviation of the timing node and the timing node corresponding to the specified zero-crossing moment in the same voltage waveform cycle of the same phase line according to the first timing information and the second timing information includes:

[0208] When the node to be timed is in phase with the time-setting node, obtaining the time value of the specified zero-crossing moment in the same voltage waveform cycle corresponding to the first time-setting information in the second time-setting information;

[0209] When the node being timed is out of phase with the time calibration node, the phase difference between the phase line where the node being timed is located and the phase line where the time calibration node is located is obtained, and according to the phase difference, the time value of the specified zero-crossing moment in the same phase line and the same voltage waveform period corresponding to the first time calibration information in the second time calibration information is obtained;

[0210] When there are multiple phase lines where the timing node is located, according to the time value of the specified zero-crossing moment corresponding to the phase line where the timing node is located in the first timing information, obtain the time value of the specified zero-crossing moment in the same voltage waveform period of the same phase line corresponding to the first timing information in the second timing information;

[0211] The time deviation between the first timing information and the second timing information corresponding to the same designated zero-crossing moment in the same voltage waveform cycle is calculated.

[0212] According to an embodiment of the present disclosure, if there are multiple designated zero-crossing moments, the time calibration method further includes:

[0213] The average value of the time deviations of the same designated zero-crossing moment in the first timing information and the second timing information is calculated, and the time of the node being timed is calibrated using the average value of the time deviations.

[0214] In a sixth aspect, an embodiment of the present disclosure provides a time synchronization method for a power distribution network, wherein the power distribution network adopts a layered networking mode and includes multiple layers of nodes, wherein the time synchronization nodes and the time synchronized nodes are respectively in the same layer, adjacent layers or across layers, and are connected via a power line carrier communication link and / or a wireless communication link, wherein the time synchronization method is applied to the time synchronization nodes in the power distribution network, and the time synchronization method includes:

[0215] After the time calibration is completed, the second time calibration information is generated;

[0216] The second time synchronization information is sent to the time-synchronized node, so that the time-synchronized node obtains the second time synchronization information, and performs time synchronization on the time-synchronized node based on the first time synchronization information and the obtained second time synchronization information; the first time synchronization information is the local clock timing value of the time-synchronized node obtained by the time-synchronized node at a reference time or a time having a preset relationship with the reference time, and the second time synchronization information is the local clock timing value of the time-synchronizing node obtained by the time-synchronizing node at the reference time after the time synchronization is completed;

[0217] Wherein, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: a rising edge zero-crossing time and / or a falling edge zero-crossing time;

[0218] The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner:

[0219] Obtain multiple timing times from multiple different timing sources;

[0220] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0221] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0222] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0223] According to an embodiment of the present disclosure, the sending of the second timing information to the timing-corrected node includes:

[0224] A time calibration beacon is sent to the node to be time-calibrated directly or through a relay node, wherein the time calibration beacon carries the second time calibration information.

[0225] In a seventh aspect, an embodiment of the present disclosure provides a time calibration device for a power distribution network, wherein the power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, wherein the time calibration node and the time-calibrated node are respectively in the same layer, adjacent layers or across layers, and are connected via a power line carrier communication link and / or a wireless communication link, wherein the time calibration device is arranged at the time-calibrated node in the power distribution network, and the time calibration device includes:

[0226] A first time synchronization information acquisition module is configured to acquire first time synchronization information, wherein the first time synchronization information is a local clock timing value of the time-synchronized node acquired by the time-synchronized node at a reference time or a time having a preset relationship with the reference time;

[0227] A second time synchronization information acquisition module is configured to acquire second time synchronization information, where the second time synchronization information is a local clock timing value of the time synchronization node acquired by the time synchronization node at the reference time after completing the time synchronization;

[0228] A first timing module is configured to perform timing on the timing-corrected node based on the first timing information and the second timing information;

[0229] Wherein, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: a rising edge zero-crossing time and / or a falling edge zero-crossing time;

[0230] The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner:

[0231] Obtain multiple timing times from multiple different timing sources;

[0232] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0233] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the multi-source fusion node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0234] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the multi-source fusion node is time-calibrated according to the first intermediate value set.

[0235] According to an embodiment of the present disclosure, the time calibration device further includes:

[0236] The clock self-maintaining module is configured to perform least square estimation on the local clock error after multiple calibrations to generate the first error compensation parameter and the second error compensation parameter ; According to the running values ​​corresponding to the local clock at time i-2, i-1 and i respectively And the first error compensation parameter and the second error compensation parameter Determine the predicted compensated local clock time at time i ,in,

[0237] .

[0238] In an eighth aspect, an embodiment of the present disclosure provides a time calibration device for a power distribution network, wherein the power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, wherein the time calibration nodes and the time-calibrated nodes are respectively in the same layer, adjacent layers or across layers, and are connected via a power line carrier communication link and / or a wireless communication link, wherein the time calibration device is arranged at the time calibration node in the power distribution network, and the time calibration device includes:

[0239] The first time synchronization information generating module is configured to generate the second time synchronization information after completing the time synchronization;

[0240] A first time synchronization information sending module is configured to send the second time synchronization information to the time-synchronized node, so that the time-synchronized node obtains the second time synchronization information and performs time synchronization on the time-synchronized node based on the first time synchronization information and the obtained second time synchronization information; the first time synchronization information is a local clock timing value of the time-synchronized node obtained by the time-synchronized node at a reference time or a time having a preset relationship with the reference time, and the second time synchronization information is a local clock timing value of the time-synchronizing node obtained by the time-synchronizing node at the reference time after the time synchronization is completed;

[0241] Among them, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: the rising edge zero-crossing time and / or the falling edge zero-crossing time.

[0242] The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner:

[0243] Obtain multiple timing times from multiple different timing sources;

[0244] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0245] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0246] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0247] In a ninth aspect, an embodiment of the present disclosure provides a timing device for a multi-source fusion node, wherein the multi-source fusion node supports fusion timing of multiple different timing sources, and the timing device includes: a multi-source timing time acquisition module and a multi-source timing fusion module;

[0248] The multi-source timing time acquisition module is configured to acquire multiple timing times from multiple different timing sources;

[0249] The multi-source timing fusion module is configured to determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value set is determined according to the timing times from at least two different timing sources; when there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; the first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of a designated node, wherein the designated node includes the multi-source fusion node or a node other than the multi-source fusion node; when there is one first intermediate value set, there are one or more elements in the first intermediate value set, and the first intermediate value set is used to calibrate the time of the designated node.

[0250] According to an embodiment of the present disclosure, the acquiring of multiple timing times respectively from multiple different timing sources includes:

[0251] Acquire a preferred timing source set, wherein the preferred timing source set includes a plurality of different preferred timing sources, and the preferred timing source is a timing source that satisfies an evaluation condition and is screened out from the plurality of different timing sources by evaluating them;

[0252] Based on the preferred timing source set, multiple timing times respectively from the multiple different preferred timing sources are acquired.

[0253] According to an embodiment of the present disclosure, the time calibration device further includes:

[0254] The timing error monitoring module is configured to monitor the availability of each preferred timing source in the preferred timing source set; when the number of preferred timing sources with availability in the preferred timing source set does not meet a preset number threshold, the preferred timing source set is re-determined.

[0255] In a tenth aspect, a time calibration device for a power distribution network is provided in an embodiment of the present disclosure, wherein the power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, wherein the 0th layer node is a master node, and other layer nodes except the 0th layer node are slave nodes, wherein the slave node is connected to an upper layer node via a power line carrier communication link and / or a wireless communication link, and the master node and the slave node are both provided with a zero crossing detection circuit, and the time calibration device is provided at a slave node in the power distribution network, and the time calibration device includes:

[0256] The upper node time calibration beacon receiving module is configured to receive the time calibration beacon sent by the upper node after the upper node of the slave node completes the time calibration, wherein the time calibration beacon contains the time calibration information, and the time calibration information includes: the time value of the sending time of the time calibration beacon, and the NTB time difference between the sending time and the first zero-crossing time of the phase line where the upper node sending the time calibration beacon is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the upper node sending the time calibration beacon;

[0257] An NTB time difference acquisition module is configured to acquire an NTB time difference between a reception time of the time calibration beacon and a second zero-crossing time of the phase line where the slave node is located;

[0258] A slave node timing module is configured to perform timing on the slave node according to the timing information in the received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located;

[0259] The upper node of the slave node includes: the master node, the master node is a designated node in the power distribution network, or a node that performs time synchronization through the designated node, the designated node includes a multi-source fusion node or a node other than the multi-source fusion node, the multi-source fusion node supports fusion timing of multiple different timing sources, and the designated node in the power distribution network is synchronized in the following manner through the multi-source fusion node:

[0260] Obtain multiple timing times from multiple different timing sources;

[0261] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0262] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0263] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0264] According to an embodiment of the present disclosure, the slave node is also connected to the lower node via a power line carrier communication link and / or a wireless communication link, and the timing device further includes:

[0265] The slave node time calibration beacon sending module is configured to send a time calibration beacon to the lower node after the slave node completes the time calibration, so that the lower node can calibrate the local time according to the time calibration information in the received time calibration beacon.

[0266] In an eleventh aspect, a time calibration device for a power distribution network is provided in an embodiment of the present disclosure. The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, wherein the 0th layer node is a master node, and other layer nodes except the 0th layer node are slave nodes. The master node is connected to the lower layer slave node through a power line carrier communication link and / or a wireless communication link, and the master node and the slave node are both provided with a zero crossing detection circuit. The time calibration device is provided at the master node in the power distribution network, and the time calibration device includes:

[0267] The master node time calibration beacon sending module is configured to send a time calibration beacon to the lower-layer slave node after completing the time calibration, so as to realize the time calibration of the lower-layer slave node; the time calibration beacon contains the time calibration information, so that the lower-layer slave node can calibrate the local time according to the time calibration information in the time calibration beacon and the NTB time difference between the receiving time of the time calibration beacon and the zero-crossing time of the phase line where the lower-layer slave node is located; wherein the time calibration information includes: the time value of the sending time of the time calibration beacon, and the NTB time difference between the sending time and the zero-crossing time of the phase line where the master node is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the master node;

[0268] The master node is a designated node in the power distribution network, or a node that is timed by the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to sync the designated node in the power distribution network in the following manner:

[0269] Obtain multiple timing times from multiple different timing sources;

[0270] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0271] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0272] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0273] In a twelfth aspect, an embodiment of the present disclosure provides a multi-source wide-area power distribution network hierarchical timing system, the timing system comprising a plurality of nodes, at least one of which is a multi-source fusion node, the multi-source fusion node supporting fusion timing of a plurality of different timing sources; the timing system further comprises a terminal wireless device, the terminal wireless device is connected to the node in the timing system; wherein:

[0274] The multi-source fusion node is configured to perform time synchronization on a designated node in the time synchronization system in the following manner, wherein the designated node includes the multi-source fusion node or a node other than the multi-source fusion node:

[0275] Obtain multiple timing times from multiple different timing sources;

[0276] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0277] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0278] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set;

[0279] The designated node is configured to perform time calibration on other nodes in the time calibration system after completing time calibration;

[0280] Among them, after completing the time calibration, the node in the time calibration system connected to the terminal wireless device obtains the time calibration period of the terminal wireless device according to the time error coefficient and the maximum time synchronization tolerance threshold of the terminal wireless device connected to the node; and calibrates the terminal wireless device according to the time calibration period.

[0281] In the thirteenth aspect, a chip is provided in an embodiment of the present disclosure, comprising the time calibration device described in any one of aspects seven to eleven; or, comprising a memory and a processor; wherein the memory is used to store one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the time calibration method described in any one of aspects one to six.

[0282] In the fourteenth aspect, an electronic device is provided in an embodiment of the present disclosure, comprising a memory and a processor; wherein the memory is used to store computer instructions, wherein the computer instructions are executed by the processor to implement the time calibration method described in any one of the first to sixth aspects.

[0283] In a fifteenth aspect, a computer-readable storage medium is provided in an embodiment of the present disclosure, on which computer instructions are stored. When the computer instructions are executed by a processor, the time calibration method described in any one of the first to sixth aspects is implemented.

[0284] In the sixteenth aspect, a computer program product is provided in an embodiment of the present disclosure, comprising computer instructions, which, when executed by a processor, implement the time calibration method described in any one of the first to sixth aspects.

[0285] According to the technical solution provided by the embodiment of the present disclosure, the concept of a multi-source fusion node is innovatively proposed. The multi-source fusion node can support and fuse time information from multiple different timing sources, and perform time calibration based on the fused timing time. When obtaining the fused timing time, one or more first intermediate value sets are first determined based on the multiple timing times. When there are multiple first intermediate value sets, multiple second intermediate values ​​are further calculated based on the credibility of the timing source or the deviation value between the timing times, and the optimal second intermediate value is selected as the timing reference according to preset rules. After completing the time calibration of the designated node, hierarchical time calibration is performed on other nodes in the power distribution and utilization network based on these time-calibrated nodes. This improves the time accuracy and synchronization of the high-precision power distribution and utilization business, thereby improving the reliability and stability of the entire power distribution and utilization network.

[0286] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0287] Other features, objectives and advantages of the present disclosure will become more apparent through the following detailed description of non-limiting embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0288] Figure 1 A schematic diagram of a power distribution network structure according to an embodiment of the present disclosure is shown.

[0289] Figure 2 A schematic diagram of the structure of a multi-source fusion node according to an embodiment of the present disclosure is shown.

[0290] Figure 3 A schematic diagram of the structure of another multi-source fusion node according to an embodiment of the present disclosure is shown.

[0291] Figure 4 A flowchart of a hierarchical time synchronization method for a multi-source wide-area power distribution network according to an embodiment of the present disclosure is shown.

[0292] Figure 5 A flowchart of a time synchronization method for a multi-source fusion node according to an embodiment of the present disclosure is shown.

[0293] Figure 6 A flow chart of a method for obtaining multiple timing times from multiple different timing sources according to specific embodiment 1 of the present disclosure is shown.

[0294] Figure 7 A flow chart of a method for determining the preferred timing source set according to specific embodiment 1 of the present disclosure is shown.

[0295] Figure 8A schematic diagram is shown of determining the multi-source fusion timing time according to the multiple timing times of the multiple different preferred timing sources in specific embodiment 1 of the present disclosure.

[0296] Fig. 9 A flow chart of a method for calibrating the time of a designated node according to a specific embodiment 2 of the present disclosure is shown.

[0297] Fig.10 A schematic structural diagram of a first mobile communication network and a second mobile communication network according to an embodiment of the present disclosure is shown.

[0298] Fig.11 A flow chart of a time synchronization method for a power distribution network according to an embodiment of the present disclosure is shown.

[0299] Fig.12 A schematic diagram of a power distribution network structure connection according to an embodiment of the present disclosure is shown.

[0300] Fig.13 A schematic diagram of a power distribution network structure connection in a specific application scenario according to an embodiment of the present disclosure is shown.

[0301] Fig.14 A flow chart of a method for calibrating time by a slave node according to an embodiment of the present disclosure based on the timing information in a received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero-crossing time of the phase line where the slave node is located is shown.

[0302] Fig.15 A schematic diagram of a process from sending a time calibration beacon from an upper node to receiving the time calibration beacon from a slave node according to an embodiment of the present disclosure is shown.

[0303] Fig.16 A flow chart showing another method for synchronizing time in a power distribution network according to an embodiment of the present disclosure is shown.

[0304] Fig.17 A flow chart of yet another method for synchronizing time in a power distribution network according to an embodiment of the present disclosure is shown.

[0305] Fig.18 Another schematic diagram of the connection of a power distribution network structure according to an embodiment of the present disclosure is shown.

[0306] Fig.19 A schematic diagram of a time calibration process based on a reference beacon according to a specific embodiment 1 of the present disclosure is shown.

[0307] Fig. 20 A schematic diagram of a time calibration process in a power distribution network according to a specific embodiment 1 of the present disclosure is shown.

[0308] Fig.21A flow chart showing yet another method for synchronizing time in a power distribution network according to an embodiment of the present disclosure is shown.

[0309] Fig. 22 A flowchart of a method for acquiring a timing period of a terminal wireless device connected to the node according to a time error coefficient and a maximum time synchronization tolerance threshold of the terminal wireless device according to an embodiment of the present disclosure is shown.

[0310] Fig.23 A structural block diagram of a time synchronization device for a power distribution network according to an embodiment of the present disclosure is shown.

[0311] Fig.24 A structural block diagram of another time synchronization device for a power distribution network according to an embodiment of the present disclosure is shown.

[0312] Fig.25 A structural block diagram of another time synchronization device for a power distribution network according to an embodiment of the present disclosure is shown.

[0313] Fig.26 A structural block diagram of another time synchronization device for a power distribution network according to an embodiment of the present disclosure is shown.

[0314] Fig. 27 A structural block diagram of a time synchronization device for a multi-source fusion node according to an embodiment of the present disclosure is shown.

[0315] Fig.28 A structural block diagram of an electronic device according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0316] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. In addition, for the sake of clarity, parts not related to the description of the exemplary embodiments are omitted in the accompanying drawings.

[0317] In the present disclosure, it should be understood that terms such as "include" or "have" are intended to indicate the presence of features, numbers, steps, behaviors, components, parts, or a combination thereof disclosed in the present specification, and are not intended to exclude the possibility that one or more other features, numbers, steps, behaviors, components, parts, or a combination thereof exist or are added.

[0318] It should also be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0319] As mentioned above, for the timing of power distribution and utilization terminals, traditional timing methods often rely on a single timing source. However, on the one hand, a single timing source has reliability risks. On the other hand, some commonly used timing methods in existing power systems (such as 5G communication timing, radio wave timing, etc.) are difficult to meet the urgent needs of power distribution and utilization terminals for high-precision timing synchronization due to their inherent limitations. Although the satellite timing method has high timing accuracy, the cost of the receiving equipment is relatively high, and under certain specific environmental conditions (such as inside buildings), the timing accuracy will decrease or it will not be possible to provide timing, resulting in it not being widely popularized in the power system.

[0320] For the power distribution network, the power distribution network in the prior art uses the master node as the reference when synchronizing the clocks of all nodes in the network. The master node broadcasts the timing information to the slave nodes, and the slave nodes receive the timing information and adjust their own clocks according to the received information, thereby achieving time synchronization with the master node.

[0321] In the above-mentioned time synchronization method of the prior art, all slave nodes rely on the time synchronization information of the master node for synchronization. During the transmission of the time synchronization information, due to factors such as network transmission delay and device processing time, the time synchronization information received by the slave node will have time deviation. This deviation is particularly obvious when the network scale is large or the communication conditions are complex, and it cannot meet the needs of high-precision time synchronization.

[0322] In addition, the time calibration and synchronization of each terminal meter in the substation area, the existing power line carrier signal transmission electromagnetic environment is complex, there are signal attenuation and interference from neighboring areas, resulting in a large fluctuation range of communication delays, and the relay nodes forward the information step by step, resulting in large deviations in the time synchronization of the substation nodes and accumulation of time synchronization errors at each level. At the same time, based on a single communication mode, there are problems such as incomplete coverage and inability to synchronize time throughout the entire period.

[0323] In order to meet the high-precision timing and synchronization requirements of power distribution and utilization terminals, improve the timing accuracy of each node in the power distribution and utilization network during clock synchronization, enhance the reliability and stability of the entire power distribution and utilization network, and thereby improve the time accuracy and synchronization of high-precision power distribution and utilization services, the inventors of the present invention have made improvements to the timing schemes for power distribution and utilization terminals and power distribution and utilization networks respectively after careful research and consideration.

[0324] For power distribution terminals:

[0325] On the one hand, the concept of multi-source fusion node is innovatively proposed. The multi-source fusion node can support and fuse time information from multiple different timing sources, and calibrate the time according to the fused timing time. This mechanism significantly improves the reliability and accuracy of time synchronization. In the existing technology, most systems rely on a single timing source and are easily affected by the failure or error of the timing source. Multi-source fusion timing can effectively reduce the uncertainty brought by a single timing source and improve the robustness of the system by integrating the data of multiple timing sources.

[0326] On the other hand, a complex intermediate value processing and optimization mechanism is designed. First, one or more first intermediate value sets are determined based on multiple timing times, and these sets are calculated based on the timing times of at least two different timing sources. When there are multiple first intermediate value sets, multiple second intermediate values ​​are further calculated based on the credibility of the timing source or the deviation value between the timing times, and the optimal second intermediate value is selected as the timing reference according to preset rules. This mechanism can intelligently evaluate the quality of different timing sources and select the most reliable time information as the synchronization reference, thereby improving the accuracy of time synchronization.

[0327] For the power distribution network, the traditional single synchronization method of the master node broadcasting the time synchronization information of the entire network is abandoned. On the one hand, a hierarchical time synchronization strategy is adopted, that is, after completing the time synchronization of the designated node, the other nodes in the power distribution network are hierarchically synchronized based on these synchronized nodes. This strategy not only reduces the time synchronization traffic in the network, but also improves the efficiency of time synchronization. In the prior art, time synchronization is often performed by broadcasting or flooding, resulting in heavy network load and low synchronization efficiency. The hierarchical time synchronization strategy achieves efficient propagation of time synchronization by selectively synchronizing key nodes.

[0328] On the other hand, for the terminal wireless devices in the power distribution network, a method for calculating the time synchronization period based on the time error coefficient and the maximum time synchronization tolerance threshold is proposed. This method can dynamically adjust the time synchronization period according to the actual situation of the wireless device (such as clock stability, communication delay, etc.), which not only ensures the accuracy of time synchronization, but also avoids unnecessary time synchronization operations, saves resources and energy, and thus reduces the energy consumption caused by time synchronization communication. In the prior art, the time synchronization period of wireless devices often adopts fixed values ​​or simple calculation methods, which cannot adapt to the actual needs of different devices.

[0329] Figure 1 A schematic diagram of a power distribution network structure according to an embodiment of the present disclosure is shown. The power distribution network includes multiple nodes, at least one of which is a multi-source fusion node, and the multi-source fusion node supports fusion timing of multiple different timing sources. The power distribution network also includes a terminal wireless device, which is connected to a node in the power distribution network.

[0330] The "multi-source fusion node" in the present disclosure refers to a power distribution terminal in the power distribution network that can receive and process time signals from multiple different timing sources. Generally, this can be achieved by integrating multiple different timing modules that receive and process multiple different timing source time signals in the power distribution terminal. After receiving the corresponding timing source time signal, the timing module will perform a series of signal processing and decoding operations to extract accurate timing time information (such as UTC time).

[0331] Generally, based on network planning and combined with factors such as node location, coverage, and cost budget, nodes located in the center of the power distribution network and with good communication conditions or on key paths can be selected as multi-source fusion nodes to better cover and serve the entire power distribution network. Figure 1 As shown, the multi-source fusion nodes include but are not limited to: medium voltage secondary equipment, such as: power distribution MPU, differential protection device, etc., and substation intelligent terminals, such as: central coordination node CCO, proxy coordination node PCO, etc.

[0332] Among them, the multiple different timing sources supported by the multi-source fusion node involve multiple timing sources in the air, space and ground, including but not limited to: satellite timing sources (such as Beidou, GPS, low-orbit satellite timing), ground network timing sources (such as network time protocol NTP, precision time protocol PTP), radio wave timing sources (such as long wave timing, short wave timing), 5G communication timing sources and new timing sources that have emerged with the development of technology.

[0333] The "multi-source fusion node" in the present disclosure may support only two different timing sources, or may support more than two different timing sources.

[0334] Figure 2 A schematic diagram of the structure of a multi-source fusion node according to an embodiment of the present disclosure is shown. Figure 2 The multi-source fusion node shown supports two different timing sources, namely: 5G communication timing source and satellite timing source. Among them, the satellite timing module in the multi-source fusion node receives and processes the satellite timing source time signal, and the 5G communication timing module receives and processes the 5G communication timing source time signal.

[0335] Figure 3 A schematic diagram of the structure of another multi-source fusion node according to an embodiment of the present disclosure is shown. Figure 3 The multi-source fusion node shown supports four different timing sources, namely: satellite timing source (including: Beidou, GPS, low-orbit satellite), ground network timing source, long and short wave timing source and 5G communication timing source.

[0336] In addition, the "terminal wireless device" disclosed in the present invention can be a device connected to the substation smart terminal through a wireless communication link (such as: high-speed wireless HRF communication link, narrowband wireless communication link, etc.), such as: intelligent monitoring device, fault sensor, temperature and humidity sensor, etc., used to monitor specific parameters or environmental conditions in the power grid, and communicate with the substation smart terminal wirelessly.

[0337] The technical solution provided by the embodiments of the present disclosure adopts a hierarchical timing strategy. First, the designated nodes in the power distribution network are calibrated through multi-source fusion nodes. Then, after completing the timing of the designated nodes, the other nodes in the power distribution network are calibrated based on the calibrated designated nodes. Finally, the terminal wireless devices are calibrated based on the nodes in the power distribution network.

[0338] Figure 4 FIG. 1 is a flowchart of a multi-source wide area power distribution network hierarchical timing method according to an embodiment of the present disclosure. Figure 4 As shown, the time calibration method includes the following steps S410-S430:

[0339] In step S410, the multi-source fusion node is used to calibrate the time of a designated node in the power distribution network in the following manner, wherein the designated node includes the multi-source fusion node or a node other than the multi-source fusion node.

[0340] In step S420, after the designated node completes the time calibration, other nodes in the power distribution network are calibrated based on the designated node.

[0341] In step S430, after the node in the power distribution network completes time synchronization, the time synchronization period of the terminal wireless device connected to the node is obtained according to the time error coefficient and the maximum time synchronization tolerance threshold; the terminal wireless device is time synchronized according to the time synchronization period.

[0342] For step S410:

[0343] In order to implement the above step S410, Figure 5 A flowchart of a time synchronization method for a multi-source fusion node according to an embodiment of the present disclosure is shown. The time synchronization method comprises the following steps S510-S540:

[0344] In step S510, a plurality of timing times respectively from a plurality of different timing sources are obtained;

[0345] In step S520, one or more first intermediate value sets are determined according to the multiple timing times, where the first intermediate value sets are determined according to the timing times from at least two different timing sources.

[0346] In step S530, when there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of the designated node.

[0347] In step S540, when there is one first intermediate value set, there are one or more elements in the first intermediate value set, and the first intermediate value set is used to calibrate the time of the designated node.

[0348] After executing steps S510 to S540 as above, when there are multiple first intermediate value sets, the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; when there is one first intermediate value set, the designated node is timed according to the first intermediate value set.

[0349] The following is a detailed description of the above steps S510 to S540.

[0350] For steps S510~S540, the embodiments of the present disclosure provide two specific implementation methods: specific implementation method 1 and specific implementation method 2, wherein specific implementation method 1 determines the multi-source fusion timing time based on multiple timing times respectively from multiple different timing sources, and uses the multi-source fusion timing time to calibrate the time of the designated node; specific implementation method 2 determines the timing time optimization parameters based on the timing time deviation value calculated from multiple timing times respectively from multiple different timing sources, and combines the moving average filtering algorithm improved based on Pearson correlation, and uses the timing time optimization parameters to calibrate the time of the designated node.

[0351] For specific implementation 1:

[0352] Figure 6 FIG. 1 is a flow chart of a method for obtaining multiple timing times from multiple different timing sources according to a specific embodiment 1 of the present disclosure. Figure 6 As shown, the following steps S610-620 are included:

[0353] In step S610, a preferred timing source set is obtained, wherein the preferred timing source set includes a plurality of different preferred timing sources, and the preferred timing source is a timing source that satisfies an evaluation condition and is screened out from the plurality of different timing sources by evaluating them.

[0354] In step S620, a plurality of timing times respectively from the plurality of different preferred timing sources are acquired based on the preferred timing source set.

[0355] For step S610, Figure 7 A flow chart of a method for determining the preferred timing source set according to a specific embodiment 1 of the present disclosure is shown. Figure 7 As shown, when determining the preferred timing source set, the following steps S710-730 are included:

[0356] In step S710, the timing source evaluation indicators of the multiple different timing sources are obtained, wherein the timing source evaluation indicators are used to evaluate the availability of the timing sources.

[0357] Specifically, the timing source evaluation indicators include but are not limited to: timing signal quality, timing accuracy, timing credibility and long-term availability.

[0358] Among them, the quality of the timing signal refers to the ability of the time signal emitted by the timing source to maintain its integrity and accuracy during the transmission process. A high-quality timing signal can ensure that the time information obtained by the receiving end is accurate. Parameters related to the quality of the timing signal include signal strength, signal-to-noise ratio (SNR) and jitter rate.

[0359] Timing accuracy refers to the deviation between the time information provided by the timing source and the standard time (such as UTC). A high-precision timing source can provide time information that is closer to the standard time. When obtaining it, you can do so by direct comparison, that is, compare the time information provided by the timing source with a known high-precision time standard (such as GPS time, atomic clock time), and calculate the deviation between the two; you can also do so by statistical analysis, that is, obtain the time information of the timing source multiple times over a period of time, and calculate the statistical values ​​of the deviation between these time information and the standard time (such as mean, standard deviation, etc.) to evaluate the long-term accuracy stability of the timing source; in addition, you can also consult the user manual and documentation of the timing source to check the detailed information on timing accuracy.

[0360] Timing credibility refers to the credibility of the time information provided by the timing source. A highly credible timing source can stably and reliably provide accurate time information. When acquiring, it can be judged by synchronization detection, that is, by comparing the synchronization of the time information provided by the timing source with the time pulse signal, including monitoring the frequency, phase and pulse width of the time pulse signal of the timing source, and calculating its deviation from the standard time pulse signal; it can also be evaluated by failure rate statistics, that is, by counting the number of failures and the duration of failures of the timing source within a period of time, to evaluate its stability and reliability.

[0361] Long-term availability refers to the ability of a timing source to remain available and provide time information stably over a long period of time. A timing source with high long-term availability can ensure the continuity and stability of system time. When acquiring, you can use the method of statistically calculating the available time, that is, within a preset time period (such as one year, one month, etc.), to calculate the actual available time of the timing source (that is, the time that can provide valid time information); you can also use the method of evaluating the fault recovery capability, that is, evaluating the ability of the timing source to restore and provide valid time information after a fault occurs, including the fault recovery speed and stability after recovery.

[0362] According to an embodiment of the present disclosure, the step of obtaining timing source evaluation indicators of the plurality of different timing sources includes:

[0363] Obtain a current timing mode, wherein the current timing mode includes: a conventional timing mode, an emergency timing mode, a high-precision timing mode, a regional timing mode, and a backup timing mode; and obtain timing source evaluation indicators of the multiple different timing sources under the current timing mode.

[0364] Among them, the conventional timing mode is the basic mode used when the timing system operates normally. In this mode, the system selects multiple stable and reliable clock sources for integrated timing to ensure high accuracy and stability of time. These clock sources may include satellite navigation systems (such as GPS, Beidou, etc.), ground atomic clocks, radio timing stations, etc. The conventional timing mode is suitable for most application scenarios and can provide time synchronization services that meet daily needs.

[0365] The high-precision timing mode is designed for application scenarios that require extremely high time accuracy. This mode gives priority to the most accurate signal source in the satellite navigation system, and combines it with the high-precision atomic clock on the ground for time calibration to achieve nanosecond or even picosecond time synchronization accuracy. The high-precision timing mode is suitable for scientific research, financial transactions, satellite navigation and other fields that require extremely high time accuracy.

[0366] The regional timing mode is used when an independent timing network needs to be built in a certain area due to geographical, political or technical reasons. This mode uses the clock source in the area (such as regional atomic clocks, radio timing stations, etc.) to provide time services to users in the area. The regional timing mode can ensure the accuracy and stability of time synchronization in a specific area, and is suitable for application scenarios that require regional time consistency, such as power systems, communication systems, transportation systems, etc.

[0367] The backup timing mode is designed to prevent the interruption of time service caused by the failure of the main timing source. In this mode, the system will configure a backup timing source. When a problem occurs with the main timing source, the system will automatically switch to the backup source to ensure the continuity and reliability of the time service. The backup timing mode is suitable for application scenarios that require high continuity of time services, such as financial transactions, power systems, transportation systems, etc.

[0368] In the present disclosure, in different timing modes, the timing source evaluation indicators will be different to meet the time synchronization requirements under various application scenarios and needs. For example: the timing source evaluation indicators corresponding to the conventional timing mode may include: timing accuracy, timing credibility, long-term availability and stability indicators; the timing source evaluation indicators corresponding to the high-precision timing mode may include: timing signal quality, timing accuracy, timing credibility and long-term availability; the timing source evaluation indicators corresponding to the emergency timing mode may include: timing signal quality, timing accuracy, timing credibility, coverage and response time.

[0369] The timing source evaluation indicators corresponding to each timing mode can be set according to specific application scenarios and project requirements.

[0370] When obtaining the timing source evaluation indicators of multiple different timing sources, the present invention obtains them based on the current timing mode, which can significantly improve the accuracy and stability of time synchronization, and selects and configures the timing sources more specifically to avoid unnecessary waste of resources. At the same time, the selection and configuration of the clock source according to the mode requirements can simplify the system structure, reduce the system complexity, and improve the maintainability and scalability of the system. In addition, the system can flexibly switch the timing strategies in different scenarios to meet different application requirements, which helps the system better adapt to the complex and changeable network environment and the changes in the clock source status, and improves the robustness and reliability of the system.

[0371] In step S720, a utility function is constructed according to the timing source evaluation index, and the utility values ​​of the multiple different timing sources are calculated using the utility function.

[0372] The step of constructing a utility function according to the timing source evaluation index and calculating the utility values ​​of the multiple different timing sources using the utility function includes:

[0373] Obtain the timing signal strength and / or the timing signal signal-to-noise ratio and / or the timing signal jitter rate of each timing source, and obtain the timing signal quality score of each timing source according to the timing signal strength and / or the timing signal signal-to-noise ratio and / or the timing signal jitter rate of each timing source;

[0374] Obtain the timing accuracy of each timing source, and obtain the timing accuracy score of each timing source according to the timing accuracy of each timing source;

[0375] By comparing the synchronization of the timing time of each timing source with the time pulse signal, the timing credibility of each timing source is judged, including: monitoring the frequency of the time pulse signal of each timing source, calculating the pulse deviation of each timing source, and obtaining the timing credibility score of each timing source according to the pulse deviation of each timing source;

[0376] Counting the available time of each timing source within a preset time period, obtaining the long-term availability of each timing source according to the available time of each timing source within the preset time period, and obtaining the score of the long-term availability of each timing source according to the long-term availability of each timing source;

[0377] The utility value of each timing source is calculated according to the following utility function constructed based on the score of the timing signal quality, the score of the timing accuracy, the score of the timing credibility and the score of the long-term availability:

[0378] ;

[0379] in, represents the utility value of the i-th timing source, represents the score of the timing signal quality of the i-th timing source, The weight representing the quality of the timing signal of the i-th timing source; represents the score of the timing accuracy of the i-th timing source, Represents the weight of the timing accuracy of the i-th timing source; Indicates the score of the timing reliability of the i-th timing source; Represents the weight of the timing credibility of the i-th timing source; represents the score of the long-term availability of the i-th timing source, Represents the weight of the long-term availability of the i-th timing source. The weight of each timing source evaluation indicator can be determined according to the actual application scenario and requirements.

[0380] When obtaining the score of each timing source evaluation indicator, the data of each timing source evaluation indicator can be standardized, and then the scoring rules can be set according to the standardized data. For example, all timing accuracy values ​​are converted into deviations relative to a certain benchmark (such as seconds or milliseconds), and then the scoring rules are set according to the deviation of the timing accuracy. The smaller the deviation, the higher the score. Specifically, the deviation can be mapped to the scoring range by using piecewise functions or linear functions.

[0381] In step S730, the multiple different timing sources are sorted from high to low according to the utility values, and according to the sorting result, a preset number of timing sources are selected to form the preferred timing source set.

[0382] Among them, the preset number can be determined according to actual needs and application scenarios, and it represents the number of optimal timing sources that the system can support or use.

[0383] For step S620, when obtaining multiple timing times respectively from the multiple different preferred timing sources based on the preferred timing source set, in order to reduce the timing error and ensure that the multiple timing times are the timing times for the same moment, it is necessary to ensure that the sending of the timing request and the receiving of the timing response are completed in the shortest possible time to minimize the inconsistency of the return time between different timing sources. For example: timing requests can be sent to all preferred timing sources in parallel, which means sending timing requests to each timing source at almost the same time point (milliseconds or shorter), which can be achieved through multi-threading, asynchronous programming, etc.; then when sending each timing request, the precise timestamp of the request is recorded, and when the timing response is received from each timing source, the precise timestamp of the reception is also recorded, and then the timestamp of the timing source (the time when the timing source generates the response) is extracted from the timing response. For each timing source, the sending and receiving timestamps are used to calculate the network delay and possible clock deviation, and the calculated time deviation is used to correct the timing time received from the timing source. The estimated values ​​of the network delay and clock offset can be subtracted from the timestamp of the timing source to obtain a value closer to the actual specified historical moment.

[0384] The above step S520 includes two cases. The first case is to determine a first intermediate value set according to the multiple timing times. The second case is to determine one or more first intermediate value sets according to the multiple timing times.

[0385] For the first case, according to an embodiment of the present disclosure, determining a first intermediate value set according to the multiple timing times includes:

[0386] The timing accuracy and comprehensive credibility of each timing source are obtained; wherein the comprehensive credibility is determined based on the stability parameter, accuracy parameter and environmental factor of the corresponding timing source.

[0387] The timing accuracy range of each timing source is determined according to the timing accuracy of each timing source.

[0388] The credible density of each timing source is determined according to the timing accuracy interval and the comprehensive credibility of each timing source, and the credible density is the comprehensive credibility divided by the length of the timing accuracy interval.

[0389] The credible density of each timing source is normalized.

[0390] The multi-source fused timing time is calculated according to the timing time of each timing source and the credible density of each timing source after normalization, and the multi-source fused timing time forms the first intermediate value set.

[0391] According to an embodiment of the present disclosure, the method of calculating the multi-source fusion timing time according to the timing time of each timing source and the credible density of each timing source after normalization includes:

[0392] The multi-source fusion timing time is calculated using the following formula: :

[0393] ;

[0394] in, is the timing time of the i-th timing source; is the normalized credible density of the i-th timing source, =1, n is the total number of timing sources.

[0395] The first intermediate value set is used to calibrate the time of the designated node in the following manner, including:

[0396] The multi-source fusion timing is used to calibrate the time of the designated node.

[0397] The present disclosure introduces the concept of comprehensive credibility when calculating the trust density of the timing source. By comprehensively considering the stability parameters, accuracy parameters and environmental factors of the preferred timing source to determine the comprehensive credibility, the reliability of each timing source can be evaluated more comprehensively, which helps to identify and exclude those timing sources that are accurate in the short term but have poor long-term stability or are greatly affected by the environment, thereby improving the long-term stability and reliability of the entire timing system. Among them, when calculating the comprehensive credibility, the introduction of environmental factors enables the comprehensive credibility to be dynamically adjusted to reflect the real-time performance of the timing source under different conditions. This mechanism enhances the adaptability and flexibility of the timing system to different environmental changes, so that it can maintain a high timing accuracy in different application scenarios.

[0398] In addition, when calculating the benchmark timing time according to the timing time of each preferred timing source, using the credible density as a weight can more accurately allocate the contribution of each timing source when calculating the benchmark timing time. Specifically, a timing source with high precision and high credibility will be given a higher weight, thereby more significantly affecting the determination of the final benchmark timing time and ensuring the accuracy of the result.

[0399] For the second case, according to an embodiment of the present disclosure, determining one or more first intermediate value sets according to the multiple timing times includes:

[0400] Get the timing accuracy of each preferred timing source.

[0401] The timing range of each preferred timing source is determined according to the timing accuracy and timing time of each preferred timing source.

[0402] The intersection interval formed by the intersection of each timing range interval is determined by comparing the timing range intervals of each preferred timing source; wherein the two interval endpoints of the intersection interval form the first intermediate value set, then: the elements in the first intermediate value set correspond to the two interval endpoints of the intersection interval

[0403] In the second case, for steps S530 and S540, when the first intermediate value set is one, the first intermediate value set is used to calibrate the time of the designated node in the following manner, including:

[0404] The average value of the two interval endpoints in the first intermediate value set is used as the multi-source fusion timing time, and the multi-source fusion timing time is used to calibrate the time of the designated node.

[0405] In the second case, when there are multiple first intermediate value sets, determining multiple corresponding second intermediate values ​​according to the multiple first intermediate value sets respectively includes:

[0406] The second intermediate value corresponding to each first intermediate value set is determined as follows:

[0407] The timing accuracy interval of each preferred timing source corresponding to the first intermediate value set is determined according to the timing accuracy of each preferred timing source corresponding to the first intermediate value set.

[0408] The credible density of each preferred timing source corresponding to the first intermediate value set is determined according to the credibility and timing precision interval of each preferred timing source corresponding to the first intermediate value set, and the credible density is the credibility divided by the length of the timing precision interval.

[0409] The second intermediate value corresponding to the first intermediate value set is determined based on the maximum of the credible densities of the preferred timing sources corresponding to the first intermediate value set and the length of the intersection interval corresponding to the first intermediate value set, and the second intermediate value is the product of the maximum and the length of the intersection interval.

[0410] According to an embodiment of the present disclosure, the selecting a preferred second intermediate value from a plurality of second intermediate values ​​according to a preset rule includes:

[0411] selecting a maximum of the plurality of second intermediate values ​​as the preferred second intermediate value;

[0412] The first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of the designated node in the following manner, including:

[0413] The average value of two interval endpoints in the first intermediate value set corresponding to the preferred second intermediate value is used as the multi-source fusion timing time, and the multi-source fusion timing time is used to calibrate the time of the designated node.

[0414] The following is an example to illustrate the above steps S510-540:

[0415] If the timing accuracy and corresponding reliability of each preferred timing source in the preferred timing source set Q are and (where i=1, 2, 3…, n, n is the number of preferred timing sources); the timing time of each preferred timing source corresponds to , then the timing range of each preferred timing source is , the timing accuracy range of each preferred timing source is: [- , ], the length of the timing accuracy interval is 2 , credible density Then: .

[0416] The timing range of each preferred timing source in the preferred timing source set Q The intersection interval formed by the intersection is (where j = 1, 2, 3…, k, k is the number of intersection intervals), then:

[0417] ,

[0418] in, The corresponding time range is [ , ], the two interval endpoints of the intersection interval are and , the length of the intersection interval is - .

[0419] Figure 8 FIG. 1 is a schematic diagram showing a method of determining a multi-source fusion timing time according to a plurality of timing times of a plurality of different preferred timing sources in a specific embodiment 1 of the present disclosure. Figure 8 As shown, taking the preferred timing source set Q containing two preferred timing sources Q1 and Q2 as an example, where Q1 is Beidou and Q2 is GPS. The timing accuracy and reliability of GPS and Beidou are equivalent, then:

[0420] The timing of Q1 is , the timing accuracy is ±20ns, and the timing accuracy range is [- , ], the reliability is 95%; the timing time of Q2 is , the timing accuracy is ±20ns, and the timing accuracy range is [- , ] with a confidence level of 95%.

[0421] Assumptions and The difference is 10ns, so the intersection interval of GPS and Beidou is: This 30ns interval is the best alternative, and the final multi-source fusion timing time is .

[0422] From this, it can be seen that the advantage of using the above scheme to determine the multi-source fusion timing time is that the accuracy can be improved to 15ns, and the credibility density is greatly improved; especially when the credibility of the two satellite sources is higher, the advantage of this method is more obvious.

[0423] When the present disclosure determines the multi-source fusion timing time through the above-mentioned specific implementation mode 1, by taking the average value of the two endpoints of the intersection interval as the multi-source fusion timing time, the error that may be caused by a single timing source can be smoothed or offset to a certain extent. Since the intersection interval is jointly determined by the timing range intervals of multiple preferred timing sources, it represents the commonly recognized range of multiple timing sources in timing time, and therefore the average value of its two endpoints is closer to the actual timing time, thereby reducing the error and improving the reliability of timing. In addition, when there are multiple intersection intervals, selecting the optimal intersection interval (based on a comprehensive consideration of the credible density and the length of the intersection interval) as the timing benchmark can minimize the error and improve the accuracy of timing.

[0424] According to an embodiment of the present disclosure, the time synchronization method further includes:

[0425] The availability of each preferred timing source in the preferred timing source set is monitored.

[0426] When the number of available preferred timing sources in the preferred timing source set does not meet a preset number threshold, the preferred timing source set is re-determined.

[0427] For example, a multi-source fusion node may be set to support an emergency timing mode. When some timing sources are unable to provide timing services due to factors such as natural disasters, the timing source evaluation index is re-determined according to the emergency timing mode settings, and the timing sources that can provide timing services are verified in accordance with the above-mentioned method for determining the preferred timing source set (steps S710-730), with priority given to timing sources that are autonomous, controllable, and have high long-term stability.

[0428] In addition, the multi-source fusion node can be set to support the low-power timing mode. The multi-source fusion node evaluates the power consumption of the timing modules corresponding to each timing source. After determining the preferred timing source, other unnecessary timing modules are controlled to enter low power consumption or standby mode; or, the timing modules corresponding to the timing sources that help improve the timing accuracy are kept working; or, the timing modules corresponding to the alternative timing sources are put into hot standby state.

[0429] According to an embodiment of the present disclosure, monitoring the availability of each preferred timing source in the preferred timing source set includes:

[0430] The local clock error of the multi-source fusion node after the time calibration is estimated by least squares to generate a first error compensation parameter and the second error compensation parameter .

[0431] According to the running values ​​corresponding to the i-2, i-1 and i moments of the local clock of the multi-source fusion node, And the first error compensation parameter and the second error compensation parameter Get the time of the local clock i of the multi-source fusion node for prediction compensation ,in,

[0432] ;

[0433] The timing time of each preferred timing source in the preferred timing source set at the time i is obtained, and is recorded as: ; n represents the number of preferred timing sources in the preferred timing source set.

[0434] The error between the timing time of each preferred timing source at time i in the preferred timing source set and the time of the local clock of the multi-source fusion node at time i of the prediction compensation is calculated respectively, wherein the timing time of the jth preferred timing source at time i is The error between the time at the local clock i of the multi-source fusion node compensated by the prediction Denoted as:

[0435] ;

[0436] It is determined whether each error is greater than a set error threshold. If so, it is determined that the corresponding preferred timing source is not available, and the corresponding preferred timing source is deleted from the preferred timing source set.

[0437] The "running value" mentioned above refers to the time value recorded or measured by the multi-source fusion node at each specific time point (such as time i-2, i-1, i) under its internal clock source. These time values ​​reflect the time maintained by the multi-source fusion node by its internal clock source (such as crystal oscillator) without an external timing source.

[0438] The present disclosure can eliminate those timing sources with poor performance by redetermining the preferred timing source set, and introduce new and more accurate timing sources, which helps to improve the timing accuracy of the entire system and ensure that the time information provided is more accurate and reliable.

[0439] For specific implementation 2:

[0440] In the present disclosure, the technical solution of Specific Implementation 2 involves two different timing sources, namely, the timing source to be corrected and the reference timing source. The timing source to be corrected includes those timing sources that are difficult to meet the high-precision timing synchronization requirements of power distribution and utilization terminals due to their inherent limitations, such as 5G communication timing sources. The nodes supporting the timing source to be corrected are timed based on the timing time optimization parameters determined by the multi-source fusion node to improve the timing accuracy.

[0441] In specific implementation 2, the multi-source fusion node is in the first mobile communication network, and the multiple different timing sources supported by the multi-source fusion node include a mobile communication air interface timing source and a preset reference timing source, wherein the mobile communication network can be a 5G communication network, or other communication networks that support time calibration through the air interface, such as: 5G-Advanced (5G-A), the sixth generation mobile communication network (6th Generation Mobile Networks, referred to as 6G) or other evolved wireless communication networks. The mobile communication air interface timing source mainly refers to the timing source that provides time synchronization information to the mobile terminal through the air interface (ie: air interface) in the mobile communication network. This timing mode usually involves a wireless communication process between a base station (such as eNodeB or gNodeB) and a mobile terminal (such as a mobile phone, an Internet of Things device, etc.).

[0442] The reference timing source generally refers to a high-precision time point that can be accepted by the terminal and used as a time standard based on the timing time obtained. When determining the reference timing source, it is necessary to comprehensively consider factors such as the stability, reliability, precision, accuracy, coverage, etc. of the timing source, and give priority to timing sources with high stability and reliability, high timing precision, high accuracy and wide coverage as the reference timing source. Satellite timing sources are usually selected as reference timing sources because of their high timing accuracy and wide global coverage. Among them, the high-precision atomic clocks carried on Beidou satellites can provide nanosecond-level or even higher precision time synchronization, which provides a guarantee for the accuracy and high precision of the reference timing time.

[0443] At the same time, the preset reference timing source can also be updated regularly. By evaluating the supported timing sources, the timing source with the highest timing accuracy can be selected to replace the preset reference timing source. In this way, if the current reference timing source fails or the accuracy decreases, it can be quickly switched to other high-precision timing sources, ensuring the high-precision timing synchronization needs of power distribution and power consumption terminals at all times.

[0444] In addition, while mainly relying on a preset reference timing source, other timing sources can also be introduced as alternative reference timing sources. When the preset reference timing source fails or is interfered with and the timing conditions are not met, it is possible to switch to the alternative reference timing source and obtain the reference timing time based on the alternative reference timing source to improve the overall reliability and stability of the system.

[0445] Taking the 5G communication network as an example, the current method based on 5G air interface timing is:

[0446] Each wireless base station completes time synchronization, and the 5G power distribution terminal obtains the system information (including SIB9) and timing advance (TA value) of the base station. The 3GPPTS36.331 and 3GPPTS38.331 standards define that the base station broadcasts the system frame number (SFN) to the terminal device once every 10ms. The SIB9 data block in the SFN data frame contains information related to the Coordinated Universal Time (UTC). ; To ensure that signals in the same subframe but in different frequency domain resources can reach the base station at the same time, it is necessary to estimate the propagation delay from the base station to the 5G terminal, adjust the time when the terminal sends the signal, and ensure that the uplink transmission of all terminals is synchronized. By detecting the distance of the uplink signal from the base station, the base station side obtains the TA value and feeds the TA value back to the terminal through a downlink message. The terminal adjusts the signal sending time on its side according to the TA.

[0447] The actual propagation delay from the base station to the 5G terminal is derived from the time advance TA The actual propagation delay from the base station to the 5G terminal is derived from the time advance TA. This step includes two cases:

[0448] (a) The terminal DTU first enters the network. The base station determines the TA value by measuring the received PRACH Preamble, and the propagation delay from the base station to the 5G terminal can be obtained. for

[0449]

[0450] Among them, the index value corresponding to TA is 0-3846. The minimum time unit of 5GNR is 0.5086 ns. is the subcarrier SCS index, including 0, 1, 2, 3, and 4. A higher subcarrier SCS index is preferred, which has the advantages of lower delay error and lower air interface scheduling delay in communication transmission.

[0451] (b) TA value update. Due to changes in the base station cell accessed by the terminal or base station restart, the TA still needs to be updated. The base station determines the offset of the TA at this moment by measuring the uplink transmission signal. The propagation delay in this case is for:

[0452]

[0453] in, Save the previous actual TA adjustment value for the terminal;

[0454] According to the reference time signal and propagation delay ( and ), 5G terminal side correction time for:

[0455]

[0456] The wireless side determines the TA value by measuring the peak value of the signal energy. The TA value is affected by the signal-to-noise ratio, the number of physical resource blocks, the wireless bandwidth, the base station restart, the signal change, etc. In order to further improve the time accuracy between terminals, the present disclosure proposes a 5G base station air interface timing error compensation method, that is, using the timing time optimization parameters to compensate the above-mentioned reference time signal. and propagation delay The determined timing time is further compensated to improve the timing accuracy.

[0457] Fig. 9 FIG. 2 shows a flow chart of a method for calibrating the time of a specified node according to a specific embodiment 2 of the present disclosure. Fig. 9 As shown, the following steps S910-980 are included:

[0458] In step S910, the timing time of n historical moments corresponding to the preset reference timing source is obtained to form a first timing time sequence; wherein n is a positive integer greater than a preset threshold.

[0459] In step S920, the timing time of the mobile communication air interface timing source corresponding to the n historical moments is obtained to form a second timing time sequence.

[0460] In step S930, the timing time deviation value between the first timing time sequence and the second timing time sequence corresponding to each historical moment is calculated to form an original timing time deviation value sequence.

[0461] The original timing time deviation value sequence can be obtained by measuring the SFN data frame sent by the 5G base station in a period of 10ms.

[0462] In step S940, based on each window length value in the preset multiple window length values, the original timing time deviation value sequence is subjected to moving average filtering processing to generate multiple filtered timing time deviation value sequences corresponding to the multiple window length values ​​respectively, and the filtered timing time deviation value sequences form the first intermediate value set.

[0463] Then: the elements in the first intermediate value set correspond to each sequence value in the filtered timing time deviation value sequence, wherein the filtered timing time deviation value sequence corresponding to the window length value is determined in the following manner:

[0464] ,

[0465] in, represents the ith sequence value in the filtered timing time deviation value sequence, m represents the window length value, Represents the ijth sequence value in the original timing time deviation value sequence.

[0466] In step S950, the second intermediate value corresponding to each first intermediate value set is determined in the following manner, including:

[0467] The Pearson coefficient p is calculated according to the original timing time deviation value sequence and the filtered timing time deviation value sequence corresponding to the first intermediate value set, and the Pearson coefficient p is the second intermediate value corresponding to the first intermediate value set.

[0468] Wherein, the Pearson coefficient p is expressed by the following formula:

[0469] ,

[0470] in, It is represented as the i-th sequence value in the original timing time deviation value sequence, and are respectively the means of the original timing time deviation value sequence and the filtered timing time deviation value sequence, is the covariance of the original timing time deviation value sequence and the filtered timing time deviation value sequence, and are respectively the standard deviations of the original timing time deviation value sequence and the filtered timing time deviation value sequence.

[0471] In step S960, the multiple Pearson coefficients corresponding to the multiple window length values ​​are compared with the preset Pearson coefficient threshold value respectively, and the Pearson coefficient among the multiple Pearson coefficients that is closest to the preset Pearson coefficient threshold value is used as the preferred second intermediate value.

[0472] In step S970, the timing time optimization parameter is determined according to the nth sequence value in the filtered timing time deviation value sequence corresponding to the preferred second intermediate value and the air interface transmission delay corresponding to the nth historical moment of the mobile communication air interface timing source.

[0473] Among them, the timing optimization parameter Use the following formula to express it:

[0474] ,

[0475] in, is the nth filtered timing deviation sequence value, is the air interface transmission delay corresponding to the nth historical moment.

[0476] In step S980, the timing time optimization parameter is used to correct the timing time of the mobile communication air interface timing source, and the corrected timing time of the mobile communication air interface timing source is used to calibrate the time of the designated node.

[0477] According to an embodiment of the present disclosure, the using the timing time optimization parameter to correct the timing time of the mobile communication air interface timing source includes:

[0478] Obtain the reference time and the time advance TA sent by the mobile communication air interface timing source;

[0479] Determine the current air interface transmission delay according to the time advance TA;

[0480] The sum of the current air interface transmission delay and the reference time sent by the mobile communication air interface timing source is used as the timing time of the mobile communication air interface timing source;

[0481] The timing time of the mobile communication air interface timing source is corrected using the following formula based on the timing time optimization parameter:

[0482] ,

[0483] in, is the corrected timing time of the mobile communication air interface timing source, is the reference time sent by the mobile communication air interface timing source, is the current air interface transmission delay.

[0484] According to an embodiment of the present disclosure, the designated node includes: a mobile communication timing node, the mobile communication timing node is in the first mobile communication network or the second mobile communication network, and the mobile communication timing node supports the mobile communication air interface timing source.

[0485] Fig.10 FIG. 2 shows a schematic diagram of the structure of a first mobile communication network and a second mobile communication network according to an embodiment of the present disclosure. Fig.10 As shown, in addition to the multi-source fusion node, the first mobile communication network also includes at least one mobile communication timing node. The second mobile communication network includes a mobile communication timing node but does not include a multi-source fusion node. Fig.10 In the example, the reference timing source is a satellite timing source. In order to reduce the number of satellite antennas deployed and reduce maintenance costs, the multi-source fusion node can choose to receive satellite signals through a power splitter for satellite timing. The power splitter can be selected as active or passive according to the distance between the multi-source fusion node and the power splitter. The remaining node devices can choose to complete timing and synchronization through direct communication with the multi-source fusion node or the mobile communication timing node according to the communication situation.

[0486] The method of using the timing time optimization parameter to correct the timing time of the mobile communication air interface timing source includes:

[0487] Sending the timing time optimization parameter to the mobile communication base station of the first mobile communication network, so that the mobile communication base station in the first mobile communication network carries the timing time optimization parameter to perform timing on the mobile communication timing node in the first mobile communication network, so that the mobile communication timing node in the first mobile communication network uses the timing time optimization parameter to correct the timing time of the mobile communication air interface timing source;

[0488] And / or, so that the mobile communication base station of the first mobile communication network transmits the timing time optimization parameters back to the mobile communication access layer network (such as: 5G network), so that the mobile communication access layer network sends the timing time optimization parameters to the mobile communication base station in the second mobile communication network, so that the mobile communication base station in the second mobile communication network carries the timing time optimization parameters to time the mobile communication timing nodes in the second mobile communication network, so that the mobile communication timing nodes in the second mobile communication network use the timing time optimization parameters to correct the timing time of the mobile communication air interface timing source.

[0489] According to an embodiment of the present disclosure, when the first mobile communication network includes multiple multi-source fusion nodes, the timing method further includes:

[0490] The multiple timing time optimization parameters determined by the multiple multi-source fusion nodes are sent to the mobile communication base station in the first mobile communication network, so that the mobile communication base station in the first mobile communication network determines the final timing time optimization parameter according to the multiple timing time optimization parameters.

[0491] Receive multiple timing optimization parameters corresponding to the multiple multi-source fusion nodes sent by the mobile communication base station of the first mobile communication network. For example, the first mobile communication network includes three multi-source fusion nodes: a first multi-source fusion node, a second multi-source fusion node and a third multi-source fusion node, and the three timing optimization parameters corresponding thereto are respectively , and .

[0492] The timing time of the mobile communication air interface timing source is corrected using the multiple timing time optimization parameters respectively to obtain the corresponding multiple corrected timing times of the mobile communication air interface timing source.

[0493] Specifically, the timing time of the mobile communication air interface timing source is corrected by the following formula:

[0494] ,

[0495] in, is the corrected timing time of the mobile communication air interface timing source, is the reference time sent by the mobile communication air interface timing source, is the current air interface transmission delay, Optimize the timing parameters.

[0496] Assumption: At the same time, for the first multi-source fusion node, the second multi-source fusion node and the third multi-source fusion node, the reference time sent by the mobile communication air interface timing source is , the current air interface transmission delays of the first multi-source fusion node, the second multi-source fusion node and the third multi-source fusion node are respectively , and , then for the first multi-source fusion node: Based on the above formula, use , and based on right Correction is performed, and the corresponding multiple corrected timing sources of the mobile communication air interface timing are obtained as follows: , and , for the second multi-source fusion node: Based on the above formula, use , and based on right Correction is performed, and the corresponding multiple corrected timing sources of the mobile communication air interface timing are obtained as follows: , and , for the third multi-source fusion node: Based on the above formula, use , and based on right Correction is performed, and the corresponding multiple corrected timing sources of the mobile communication air interface timing are obtained as follows: , and .

[0497] The differences between the timing of the multiple corrected mobile communication air interface timing sources and the timing of the preset reference timing source are calculated respectively to obtain multiple errors corresponding to the multiple timing time optimization parameters.

[0498] Assumption: The timing time of the preset reference timing source is , then for the first multi-source fusion node: the multiple errors corresponding to the multiple timing optimization parameters are , and , respectively: Δ , Δ and , for the second multi-source fusion node: the multiple errors corresponding to the multiple timing optimization parameters are obtained as , and , respectively: Δ , Δ and , for the third multi-source fusion node: the multiple errors corresponding to the multiple timing optimization parameters are obtained as , and , respectively: Δ , Δ and .

[0499] The multiple errors corresponding to the multiple timing time optimization parameters are sent to the mobile communication base station of the first mobile communication network, so that after the mobile communication base station of the first mobile communication network receives the multiple errors corresponding to the multiple timing time optimization parameters sent by each multi-source fusion node, the errors calculated by the multiple multi-source fusion nodes using the same timing time optimization parameters are weighted averaged to obtain multiple weighted average results, and the timing time optimization parameter of the multi-source fusion node corresponding to the smallest one of the multiple weighted average results (i.e., the weighted average result with the smallest error) is sent as the final timing time optimization parameter to the multiple multi-source fusion nodes.

[0500] Assume that the first multi-source fusion node, the second multi-source fusion node and the third multi-source fusion node respectively send the three errors calculated locally to the mobile communication base station of the first mobile communication network. In this way, the mobile communication base station of the first mobile communication network receives all nine errors, which are Δ , Δ , , Δ , Δ , , Δ , Δ and , where Δ , Δ and Δ The first multi-source fusion node, the second multi-source fusion node and the third multi-source fusion node respectively use the timing time optimization parameters of the first multi-source fusion node The first set of errors calculated, Δ , Δ and Δ The first multi-source fusion node, the second multi-source fusion node and the third multi-source fusion node respectively use the timing time optimization parameters of the second multi-source fusion node The second set of errors calculated, Δ , Δ and Δ The first multi-source fusion node, the second multi-source fusion node and the third multi-source fusion node respectively use the timing time optimization parameters of the third multi-source fusion node The third set of errors is calculated by adding each set of errors together to obtain three weighted average results, recorded as: , and ,Compare , and The size of At the very least, due to Corresponding to the timing optimization parameters of the second multi-source fusion node Therefore, the timing optimization parameters of the second multi-source fusion node are That is the final timing optimization parameter.

[0501] The final timing time optimization parameter sent by the mobile communication base station of the first mobile communication network is received, so as to use the final timing time optimization parameter to correct the timing time of the mobile communication air interface timing source.

[0502] By using multiple timing time optimization parameters determined by multiple multi-source fusion nodes to determine the final timing time optimization parameter, and using the final timing time optimization parameter to correct the timing time of the timing source to be corrected, the following beneficial effects are achieved:

[0503] 1. Improve timing accuracy:

[0504] By selecting the timing optimization parameters of the multi-source fusion node corresponding to the weighted average result with the smallest error, the timing error can be minimized and the timing accuracy can be improved.

[0505] 2. Enhance system reliability:

[0506] The participation of multiple terminals and the weighted average processing of the base station ensure that the overall timing performance of the system will not be reduced due to the failure or error of a single terminal, thereby enhancing the reliability of the system.

[0507] 3. Strong adaptability:

[0508] This method can adapt to the differences between different network environments and different terminal devices, and find the timing optimization parameters that best suit the current network environment through multi-source fusion and weighted averaging.

[0509] 4. High flexibility:

[0510] The mobile communication base station can dynamically adjust the timing optimization parameters based on the received error data, allowing the system to flexibly respond to network changes and equipment updates.

[0511] The final timing time optimization parameter sent by the mobile communication base station of the first mobile communication network is received, so as to use the final timing time optimization parameter to correct the timing time of the mobile communication air interface timing source.

[0512] Optionally, the node devices connected to the base station can build a 5G LAN group, and the timing optimization parameters can be multicasted within the group. The node devices are built into a LAN group, and the node terminals in the group can be transmitted between the node devices through multicast based on MAC minimalist layer 2 routing, which can further reduce the reliability and security of transmission.

[0513] According to an embodiment of the present disclosure, the mobile communication air interface timing source includes cellular communication air interface timing and direct communication timing, the first mobile communication network also includes a non-cellular timing node, the non-cellular timing node does not support cellular communication air interface timing and supports direct communication timing, the multi-source fusion node or the mobile communication timing node is connected to the non-cellular timing node through a direct communication link, in a specific implementation, the cellular communication air interface timing is 5G cellular communication air interface timing, and the timing method also includes:

[0514] After the designated node is timed, the delay measurement information is interacted with the non-cellular timing node through the precise time protocol PTP, so that the non-cellular timing node performs time synchronization based on the multi-source fusion node or the mobile communication timing node. Here, the node other than the multi-source fusion node in the designated node is a mobile communication timing node.

[0515] According to an embodiment of the present disclosure, the interaction of delay measurement information with the non-cellular timing node through the precise time protocol PTP so that the non-cellular timing node performs time synchronization based on the multi-source fusion node or the mobile communication timing node includes:

[0516] The multi-source fusion node or the mobile communication timing node sends a time synchronization instruction message to the non-cellular timing node at a preset period T, and the time synchronization instruction message includes the time when the time synchronization instruction message is sent. , the time when the time synchronization instruction message is sent is calibrated according to the air interface timing time of the mobile communication network, the air interface transmission delay and the air interface transmission delay optimization parameter;

[0517] After receiving the time synchronization instruction message, the non-cellular timing node records the time of receiving the time synchronization instruction message. , and obtain the time of sending the time synchronization instruction message , then send a delay measurement request message to the multi-source fusion node or the mobile communication timing node, and record the time of sending the delay measurement request message .

[0518] After the multi-source fusion node or the mobile communication timing node receives the delay measurement request message, the time of receiving the delay measurement request message is recorded. , and sending a delay measurement response message to the non-cellular timing node, wherein the delay measurement response message includes the time of receiving the delay measurement request .

[0519] After the non-cellular timing node receives the delay measurement response message, it obtains the time of receiving the delay measurement request , and according to the time when the time synchronization instruction message is sent , the time of receiving the time synchronization instruction message , the time of sending the delay measurement request message and the time of receiving the delay measurement request Calculating time delay and time deviation , and the time when the time synchronization instruction message is sent , the time delay and the time deviation Perform time synchronization with the multi-source fusion node or the mobile communication timing node.

[0520] The time delay is calculated by the following formula: :

[0521] ,

[0522] The time delay is calculated by the following formula :

[0523] ;

[0524] The non-cellular timing node is based on the time deviation within the preset period T. Calculate the frequency difference of the local clock source ,in , i represents the i-th preset period T.

[0525] The non-cellular timing node obtains the clock frequency of the multi-source fusion node or the mobile communication timing node, and uses the clock frequency of the multi-source fusion node or the mobile communication timing node as a reference, and calculates the clock frequency of the local clock source according to the difference in the local clock source frequency. Correct the frequency difference of the local clock.

[0526] The technical solution provided by the embodiment of the present disclosure takes into account time synchronization of other types of node devices in a mobile communication network, and realizes time synchronization of node terminals in a wide area.

[0527] For step S420:

[0528] With respect to synchronizing the time of other nodes in the power distribution network based on designated nodes in the power distribution network, the embodiments of the present disclosure provide two specific implementation methods, one is a time synchronization method based on a zero-crossing reference, and the other is a time synchronization method based on a reference beacon or a power line zero-crossing signal, which are described below respectively.

[0529] Fig.11 A flowchart of a time synchronization method for a power distribution network according to an embodiment of the present disclosure is shown. The time synchronization method is based on a zero-crossing reference, and specifically adopts a hierarchical time synchronization strategy based on a hierarchical structure and a zero-crossing reference, making full use of the hierarchical relationship between nodes in the network and the physical property of the zero-crossing of the phase line voltage in the power system, and optimizing the clock synchronization mechanism in the power distribution network.

[0530] Specifically, firstly, the hierarchical timing concept is introduced in the present disclosure, that is, the slave node not only receives the timing information of the master node, but also receives the timing information of its directly upper node. In this way, each node can perform timing according to its own upper node, reducing communication delay and error accumulation; secondly, the stable and measurable physical phenomenon of phase line voltage crossing zero in the power system is used to combine time calibration with power waveform. While receiving the timing information, each slave node records the NTB time difference of the local phase line voltage crossing zero, compares it with the NTB time difference in the timing information and adjusts the local time, thereby realizing accurate calibration of the local time. After each slave node completes its own timing, it sends a time calibration beacon that has been calibrated by itself to the next level node. In this way, the clock synchronization process in the entire network forms a chain of hierarchical transmission and layer-by-layer calibration. Through the accurate measurement and comparison of hierarchical timing and NTB time difference, the influence of communication delay and error accumulation on timing accuracy is effectively reduced. At the same time, the hierarchical timing method also makes the system have better fault tolerance and scalability.

[0531] Fig.12 FIG. 1 shows a schematic diagram of a power distribution network structure connection according to an embodiment of the present disclosure. Fig.12 As shown, the power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes ( Fig.12In the example of 4 layers, the nodes in the power distribution network are connected via power line carrier communication links and / or wireless communication links; the multi-layer nodes in the power distribution network include master nodes and slave nodes, the 0th layer node in the power distribution network is the master node, and the other layer nodes except the 0th layer node are slave nodes, the master node and the slave node are both provided with a zero-crossing detection circuit, and the upper layer nodes of the slave node include: the master node, the master node is a designated node in the power distribution network, or a node that is timed by the designated node in the power distribution network, the designated node includes a multi-source fusion node or a node other than the multi-source fusion node, the multi-source fusion node supports fusion timing of multiple different timing sources, and the multi-source fusion node is used to sync the designated nodes in the power distribution network based on the first intermediate value set determined in steps S510~540 above.

[0532] Specifically, the master node includes but is not limited to the central coordination node CCO. The CCO can manage multiple devices in the substation area, such as electricity meters, branch switches, etc., and realize data collection and transmission through communication methods such as broadband carriers. Therefore, CCO is usually selected as the master node because of its powerful communication capabilities and key role in the substation network. With the continuous development of technologies such as the Internet of Things and edge computing, the master nodes in the power distribution network may be more diversified in the future. For example, devices with stronger processing capabilities and more integrated functions, such as smart fusion terminals and edge computing devices, may also become master nodes. In the embodiments of the present disclosure, the master node is taken as CCO for illustrative purposes.

[0533] The slave nodes include but are not limited to proxy coordination nodes PCO and / or stations STA. With the continuous development of Internet of Things technology, more new smart devices may be connected to the power distribution network in the future. These devices may have multiple functions such as data collection, processing, and communication, thus becoming new slave nodes. In the embodiments of the present disclosure, the slave nodes are PCO and / or STA for exemplary description.

[0534] The slave node is connected to the upper node via a power line carrier communication link (such as a high-speed power line carrier communication link) and / or a wireless communication link (such as a high-speed wireless HRF communication link). In the present disclosure, the upper node refers to the direct upper node of the adjacent level.

[0535] Fig.13 FIG. 1 shows a schematic diagram of a power distribution network structure connection in a specific application scenario according to an embodiment of the present disclosure. Fig.13 As shown, CCO is the PCO in the first layer node 1-1 、PCO 1-2 , STA 1-1 , STA 1-2 The upper node, PCO1-1 PCO for Layer 2 nodes 2-1 , STA 2-1 The upper node, PCO 1-2 PCO for Layer 2 nodes 2-2 , STA 2-2 , STA 2-3 The upper node, PCO 2-1 STA in the layer 3 node 3-1 , STA 3-2 The upper node, PCO 2-2 STA in the layer 3 node 3-3 , STA 3-4 The upper node of .

[0536] The master node and slave node involved in the embodiments of the present disclosure are both provided with a high-precision zero-crossing detection circuit, which detects the zero-crossing moment of the phase line. For the master node, the master node is configured with a high-precision zero-crossing detection circuit that can simultaneously detect the three-phase power lines A, B, and C, and can capture each zero-crossing point of the three-phase voltage in real time, that is, the moment when the voltage crosses the zero point from positive to negative (or from negative to positive) in each power frequency cycle. Whenever the zero-crossing point of any phase is detected, the master node will accurately record the timestamp of the moment and accurately establish a sequence of three-phase zero-crossing NTB moments; unlike the master node, the slave node is usually only responsible for detecting the voltage zero-crossing point of the phase (A, B or C) to which it is connected. When the slave node detects that the voltage of the phase line to which it is connected crosses zero, it will also record the timestamp of this moment. Normally, the accuracy of the high-precision zero-crossing detection circuit is around 2μs.

[0537] The timing method is applied to slave nodes in the power distribution network, such as Fig.11 As shown, the time calibration of other nodes in the power distribution network based on the designated node includes the following steps S1110~S1130:

[0538] In step S1110, after the upper node of the slave node completes time calibration, it receives a time calibration beacon sent by the upper node, wherein the time calibration beacon contains time calibration information, and the time calibration information includes: the time value of the sending time of the time calibration beacon, and the NTB time difference between the sending time and the first zero crossing time of the phase line where the upper node that sends the time calibration beacon is located. The time value of the sending time of the time calibration beacon is timed by the local clock of the upper node that sends the time calibration beacon.

[0539] When a slave node in the power distribution network performs time calibration, the upper node that calibrates the slave node needs to complete the time calibration. Fig.13The PCO2-1 shown in the figure requires PCO1-1 to complete the time calibration according to the time calibration information in the time calibration beacon sent by CCO before PCO1-1 can send a time calibration beacon to PCO2-1, and then PCO2-1 will perform time calibration according to the time calibration information in the time calibration beacon received from PCO1-1. In this way, when the upper node of the slave node completes the time calibration, it obtains accurate time information, thereby establishing a reliable time reference for the subsequent sending of time calibration information to the slave node. If the time of the upper node itself is inaccurate, the time calibration information it sends to the slave node will also contain errors. This error will accumulate with the expansion of the network and the passage of time, and ultimately lead to a significant reduction in the time synchronization accuracy of the entire network. Therefore, ensuring that the upper node completes the time calibration before the slave node performs the time calibration can minimize the accumulation of such errors.

[0540] Among them, the time value of the sending time contained in the time calibration beacon refers to the specific time point when the upper node sends the message, which is timed by its local clock, and the time value of the sending time is used for subsequent time calculation and calibration of the slave node. The NTB time difference contained in the time calibration beacon refers to the NTB time difference between the sending time of the upper node sending the time calibration beacon and the first zero-crossing time of the phase line where the upper node is located. The first zero-crossing time refers to the specified zero-crossing time among multiple zero-crossing times of the phase line where the upper node is located, for example: it can be the zero-crossing time from negative to positive of the phase line voltage closest to the sending time, which represents a relatively stable and predictable time point and is used as a reference benchmark when sending the time calibration beacon. Since the upper node (master node or slave node) has the ability to collect the power frequency zero-crossing points of three-phase line or single-phase line and can record the three-phase or single-phase zero-crossing NTB time sequence, when the upper node specifically obtains the NTB time difference, it can directly obtain the NTB time difference between the current time and the first zero-crossing time through the zero-crossing detection circuit while sending the time calibration beacon.

[0541] According to an embodiment of the present disclosure, the NTB time difference includes: any one or more of the first NTB time difference, the second NTB time difference and the third NTB time difference. For example, when the upper node is the master node, the NTB time difference contained in the timing information sent by the master node may include: the first NTB time difference, the second NTB time difference and the third NTB time difference; when the upper node is a slave node, and the phase line where the slave node is located is any one of the A, B, and C phases, or the slave node uses any one of the multiple phase lines connected to it for timing, then the NTB time difference contained in the corresponding timing information may include: any one of the first NTB time difference, the second NTB time difference and the third NTB time difference, wherein the first NTB time difference, the second NTB time difference and the third NTB time difference correspond to three different phase lines respectively. In a specific embodiment, the first NTB time difference corresponds to the A phase line, the second NTB time difference corresponds to the B phase line, and the third NTB time difference corresponds to the C phase line.

[0542] For example: for the master node, since it can simultaneously detect the zero-crossing moment of the three-phase lines A, B, and C, when the master node, as an upper-level node, sends a time calibration beacon, there are three NTB time differences contained in the timing information, namely: the NTB time difference between the sending moment of the time calibration beacon and the zero-crossing moment of phase A, the NTB time difference between the sending moment of the time calibration beacon and the zero-crossing moment of phase B, and the NTB time difference between the sending moment of the time calibration beacon and the zero-crossing moment of phase C; for the slave node, if the slave node can only detect the zero-crossing moment of one phase line, then when the slave node, as an upper-level node, sends a time calibration beacon, there is only one NTB time difference contained, namely: the NTB time difference corresponding to the phase line where the upper-level node is located, for example: if the phase line where the upper-level node is located is phase A, then the NTB time difference contained in the time calibration beacon sent by the upper-level node is the NTB time difference between the sending moment of the time calibration beacon and the zero-crossing moment of phase A.

[0543] In step S1120, the NTB time difference between the reception time of the time calibration beacon and the second zero-crossing time of the phase line where the slave node is located is obtained.

[0544] Since the slave node has the capability of collecting the single-phase line power frequency zero-crossing points and can record the single-phase zero-crossing NTB moment sequence, when the slave node specifically obtains the NTB time difference, it can directly obtain the NTB time difference between the current moment and the second zero-crossing moment through the zero-crossing detection circuit while receiving the time calibration beacon. The second zero-crossing moment refers to a specified zero-crossing moment among multiple zero-crossing moments of the phase line where the slave node is located, for example, it can be the zero-crossing moment from negative to positive of the phase line voltage closest to the receiving moment.

[0545] The first zero-crossing moment and the second zero-crossing moment may be the same zero-crossing moment. For example, if the slave node and the upper node agree to obtain the NTB time difference based on the most recent zero-crossing moment, then when the upper node and the slave node are in-phase nodes and the time calibration beacon is transmitted in the same power frequency cycle, the first zero-crossing moment and the second zero-crossing moment are the same zero-crossing moment.

[0546] Alternatively, there is a preset relationship between the first zero-crossing moment and the second zero-crossing moment. For example: when the upper node and the slave node are in-phase nodes, but the time calibration beacon is transmitted to the slave node after crossing a power frequency cycle, when the slave node obtains the NTB time difference between the reception time of the time calibration beacon and the second zero-crossing moment of the phase line where the slave node is located, if the nearest zero-crossing moment of the phase line is used as the second zero-crossing moment, then the second zero-crossing moment is one power frequency cycle longer than the first zero-crossing moment. For another example: when the upper node and the slave node are not in-phase nodes, assuming that the upper node is an A-phase node and the slave node is a B-phase node, if the upper node and the slave node both obtain the NTB time difference based on the nearest zero-crossing moment, and the time calibration beacon is transmitted in the same power frequency cycle, then the first zero-crossing moment is the A-phase zero-crossing moment closest to the sending moment, the second zero-crossing moment is the B-phase zero-crossing moment closest to the receiving moment, and the difference between the first zero-crossing moment and the second zero-crossing moment is the time difference between the A and B phases. This time difference can be calculated in a known manner.

[0547] In step S1130, the slave node is timed according to the time calibration information in the received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located.

[0548] Fig.14 A flow chart of a method for performing time calibration from a slave node according to an embodiment of the present disclosure according to the time calibration information in a received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located is shown, as shown in FIG. Fig.14 As shown, it can be achieved by following the steps S1410 to S1440:

[0549] In step S1410, a time calibration NTB time difference is obtained according to the NTB time difference in the time calibration information, and the time calibration NTB time difference corresponds to the phase line where the slave node is located.

[0550] The principle of time calibration for the slave node in the embodiment of the present disclosure is to use the time value of the sending moment of the time calibration beacon sent by the upper node as the reference time, and obtain the transmission delay between the sending and receiving of the time calibration beacon based on the same zero-crossing moment or two zero-crossing moments with a preset relationship, and then the slave node adjusts the local time to be synchronized with its upper node according to the transmission delay and the reference time.

[0551] Based on the fact that the slave node and the upper node may be located on different phase lines and the upper node may be a master node and a slave node, when obtaining the time calibration NTB time difference used to calculate the time calibration beacon transmission delay time involved in the following step S1420, it is divided into the following three scenarios:

[0552] The first scenario: when the upper node is the master node, that is, when the NTB time difference in the timing information includes the first NTB time difference, the second NTB time difference and the third NTB time difference, the NTB time difference in the timing information corresponding to the phase line where the slave node is located is used as the timing NTB time difference.

[0553] Fig.15 A schematic diagram of a process from sending a time calibration beacon from an upper node to receiving the time calibration beacon from a slave node according to an embodiment of the present disclosure is shown.

[0554] like Fig.15 As shown, when the master node CCO, as the upper node, calibrates the slave node, the calibration information in the sent time calibration beacon contains three NTB time differences, namely: the NTB time difference between the sending time of the time calibration beacon and the most recent A phase zero crossing time , the NTB time difference between the sending time of the time calibration beacon and the most recent B phase zero crossing time , and the NTB time difference between the sending time of the time calibration beacon and the most recent C phase zero crossing time .

[0555] When the slave node is Figure 4 When the A phase STA1 is shown, the slave node does not select all three NTB time differences sent by the master node when calibrating the time, but selects the NTB time difference corresponding to its own phase line as the calibration NTB time difference for calculating the transmission delay time of the time calibration beacon, that is: .

[0556] Accordingly, when the slave node is Fig.15 When the B phase STA2 is shown, the slave node selects As the time difference of the calibration beacon transmission delay time; when the slave node is Fig.15When the C phase STA3 is shown, the slave node is selected The NTB time difference is used as the time calibration beacon transmission delay time calculation.

[0557] The second scenario: when the upper node is a slave node, that is, when the NTB time difference in the timing information is any one of the first NTB time difference, the second NTB time difference, and the third NTB time difference, and the upper node that sends the time calibration beacon and the slave node are in-phase nodes, the NTB time difference in the timing information is used as the timing NTB time difference.

[0558] like Fig.15 As shown, when A-phase STA1, as the upper node, calibrates the time of slave node A-phase STA5, since the phase lines of both are in phase A, A-phase STA5 can directly use the NTB time difference in the timing information sent by A-phase STA1 as the timing NTB time difference for calculating the time calibration beacon transmission delay time.

[0559] The third scenario: when the upper node is a slave node, that is, when the NTB time difference in the timing information is any one of the first NTB time difference, the second NTB time difference, and the third NTB time difference, and the upper node that sends the time calibration beacon and the slave node are not in phase, obtain two NTB time differences in the time calibration beacon sent by the master node that correspond to the phase line where the slave node is located and the phase line where the upper node that sends the time calibration beacon is located, obtain the difference between the two NTB time differences, and subtract the difference from the NTB time difference in the timing information to obtain the timing NTB time difference.

[0560] In the present disclosure, all slave nodes in the power distribution network can receive the timing information sent by the master node. However, when performing timing, in the first and second scenarios mentioned above, the slave node only needs to use the timing information sent by the upper node for timing. In the third scenario, since the upper node and the slave node are located on different phase lines, when calculating the time calibration beacon transmission delay time, it is necessary to accurately obtain the zero-crossing moment based on the same phase line. Therefore, when performing timing, the slave node not only needs the timing information sent by the upper node, but also needs to be combined with the timing information sent by the master node.

[0561] According to an embodiment of the present disclosure, it is assumed that: the first NTB time difference corresponds to the A-phase line, the second NTB time difference corresponds to the B-phase line, and the third NTB time difference corresponds to the C-phase line.

[0562] Then: the step of obtaining two NTB time differences in the time calibration beacon sent by the master node, which correspond to the phase line where the slave node is located and the phase line where the upper node that sends the time calibration beacon is located, and obtaining the difference between the two NTB time differences, includes:

[0563] If the phase line where the slave node is located is phase B, the NTB time difference corresponding to the phase line where the slave node is located in the time calibration beacon sent by the master node is the second NTB time difference in the time calibration beacon sent by the master node. , if the phase line where the upper node that sends the time calibration beacon is located is phase A, then the NTB time difference corresponding to the phase line where the upper node that sends the time calibration beacon is located in the time calibration beacon sent by the master node is the first NTB time difference in the time calibration beacon sent by the master node ,but:

[0564] The time difference between the two NTB time differences is obtained by the following formula:

[0565] ;

[0566] If the phase line where the slave node is located is phase A, the NTB time difference corresponding to the phase line where the slave node is located in the time calibration beacon sent by the master node is the first NTB time difference in the time calibration beacon sent by the master node. , if the phase line where the upper node that sends the time calibration beacon is located is phase B, then the NTB time difference corresponding to the phase line where the upper node that sends the time calibration beacon is located in the time calibration beacon sent by the master node is the second NTB time difference in the time calibration beacon sent by the master node ,but:

[0567] The time difference between the two NTB time differences is obtained by the following formula:

[0568] ;

[0569] If the phase line where the slave node is located is phase A, the NTB time difference corresponding to the phase line where the slave node is located in the time calibration beacon sent by the master node is the first NTB time difference in the time calibration beacon sent by the master node. , if the phase line where the upper node that sends the time calibration beacon is located is phase C, then the NTB time difference in the time calibration beacon sent by the master node and the phase line where the upper node that sends the time calibration beacon is located corresponding to is the third NTB time difference in the time calibration beacon sent by the master node ,but:

[0570] The time difference between the two NTB time differences is obtained by the following formula:

[0571] ;

[0572] If the phase line where the slave node is located is phase C, the NTB time difference corresponding to the phase line where the slave node is located in the time calibration beacon sent by the master node is the first NTB time difference in the time calibration beacon sent by the master node. , if the phase line where the upper node that sends the time calibration beacon is located is phase A, then the NTB time difference in the time calibration beacon sent by the master node and the phase line where the upper node that sends the time calibration beacon is located corresponding to is the third NTB time difference in the time calibration beacon sent by the master node ,but:

[0573] The time difference between the two NTB time differences is obtained by the following formula:

[0574] ;

[0575] If the phase line where the slave node is located is phase C, the NTB time difference corresponding to the phase line where the slave node is located in the time calibration beacon sent by the master node is the third NTB time difference in the time calibration beacon sent by the master node. , if the phase line where the upper node that sends the time calibration beacon is located is phase B, then the NTB time difference corresponding to the phase line where the upper node that sends the time calibration beacon is located in the time calibration beacon sent by the master node is the second NTB time difference in the time calibration beacon sent by the master node ,but:

[0576] The time difference between the two NTB time differences is obtained by the following formula:

[0577] ;

[0578] If the phase line where the slave node is located is phase B, the NTB time difference corresponding to the phase line where the slave node is located in the time calibration beacon sent by the master node is the second NTB time difference in the time calibration beacon sent by the master node. , if the phase line where the upper node that sends the time calibration beacon is located is phase C, then the NTB time difference in the time calibration beacon sent by the master node and the phase line where the upper node that sends the time calibration beacon is located corresponding to is the third NTB time difference in the time calibration beacon sent by the master node ,but:

[0579] The time difference between the two NTB time differences is obtained by the following formula:

[0580] ;

[0581] The step of subtracting the difference from the NTB time difference in the time calibration information to obtain the time calibration NTB time difference includes:

[0582] When the NTB time difference in the timing information is the first NTB time difference , and when the phase line where the slave node is located is phase B, the time difference NTB Calculate using the following formula:

[0583] ;

[0584] When the NTB time difference in the timing information is the first NTB time difference , and when the phase line where the slave node is located is phase C, the time difference of the calibration NTB Calculate using the following formula:

[0585] ;

[0586] When the NTB time difference in the timing information is the second NTB time difference , and when the phase line where the slave node is located is phase C, the time difference of the calibration NTB Calculate using the following formula:

[0587] ;

[0588] When the NTB time difference in the timing information is the second NTB time difference , and when the phase line where the slave node is located is phase A, the time difference of the calibration NTB Calculate using the following formula:

[0589] ;

[0590] When the NTB time difference in the timing information is the third NTB time difference , and when the phase line where the slave node is located is phase A, the time difference of the time calibration NTB Calculate using the following formula:

[0591] ;

[0592] When the NTB time difference in the timing information is the third NTB time difference , and when the phase line where the slave node is located is phase B, the time difference NTB Calculate using the following formula:

[0593] .

[0594] like Fig.15 As shown, when the A-phase STA5 is used as an upper node to calibrate the time of the slave node B-phase STA6, in this case, the B-phase STA6 needs to first select the second NTB time difference in the time calibration beacon sent by the master node. Time difference with the first NTB , then get the time difference between the two NTB time differences , and then use the NTB time difference in the timing information sent by phase A STA5 , calculate the time difference of NTB .exist Fig.15 The calculated time difference of the calibration NTB A negative value.

[0595] In step S1420, the time calibration beacon transmission delay time is calculated according to the time calibration NTB time difference and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located.

[0596] In step S1430, the calibration time corresponding to the reception time of the time calibration beacon is calculated according to the transmission delay time of the time calibration beacon and the time value of the sending time in the timing information.

[0597] According to an embodiment of the present disclosure, the time calibration beacon transmission delay time is calculated using the following formula:

[0598] ;

[0599] The calibration time corresponding to the reception time of the time calibration beacon is calculated using the following formula:

[0600] ;

[0601] in, represents a calibration time corresponding to the reception moment of the time calibration beacon; Indicates the transmission delay time of the time calibration beacon; The time value representing the sending time in the time calibration information; represents the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located; is the power frequency cycle; n is the number of power frequency cycles spanned during the transmission of the time calibration beacon, n≥0, It is the time difference of the time calibration NTB.

[0602] For example: Fig.15 As shown, when the master node CCO, as the upper node, calibrates the time of the A-phase STA1, the master node CCO and STA1 are set to use the zero-crossing time of the phase line closest to the sending time or receiving time as the reference. Since the time calibration beacon is transmitted within a power frequency cycle, n=0, the first zero-crossing time and the second zero-crossing time are the same zero-crossing time, then from the master node CCO sending the time calibration beacon to the A-phase STA1 receiving it, the time calibration beacon transmission delay time for:

[0603]

[0604] Another example: Fig.15 As shown, when the master node CCO, as the upper node, calibrates the time of the B-phase STA2, the master node CCO and STA1 are also set to use the zero-crossing time of the phase line closest to the sending time or the receiving time as the reference. Since the B-phase STA2 has crossed a power frequency cycle relative to the sending time when receiving the time calibration beacon, n=1, and the first zero-crossing time and the second zero-crossing time are also one power frequency cycle apart. Then, from the time the master node CCO sends the time calibration beacon to the B-phase STA2 receiving it, the transmission delay time of the time calibration beacon is for:

[0605]

[0606] The A-phase STA1 and the B-phase STA2 use the following formulas to calculate the calibration time corresponding to the reception time of the time calibration beacon:

[0607]

[0608] For the slave node, it can be determined whether the time calibration beacon is received in the same power frequency cycle or is received across one or more power frequency cycles in the following manner:

[0609] When the slave node receives the time calibration beacon sent by the upper node, the time value of the receiving time of the time calibration beacon measured by the local clock of the slave node is obtained, and then the time difference between the time value of the sending time of the time calibration beacon and the time value of the receiving time of the time calibration beacon is determined. This time difference reflects the clock offset between the slave node and the upper node of the slave node. Then, the time difference is compared with a preset error threshold (for example, half of a power frequency cycle). If the time difference is less than the preset error threshold, it can be considered that the time calibration beacon is sent and received within the same power frequency cycle. Otherwise, it is considered that the time calibration beacon is not sent and received within the same power frequency cycle. As for how many power frequency cycles are spanned, it can be determined by judging the relationship between the time difference and the preset error threshold. For example, if the time difference contains a preset error threshold, it can be considered that the time calibration beacon is received across a power frequency cycle.

[0610] The above judgment method is only one of the specific implementation methods. During the specific implementation, other applicable methods can be selected according to the specific situation of the application equipment.

[0611] In step S1440, time calibration is performed using the calibration time corresponding to the reception time of the time calibration beacon.

[0612] The calculated value in step S1430 The time is timed by the local clock of the upper node of the slave node, and the slave node calibrates the local time of the reception moment of the time calibration beacon to , that is, the time synchronization with the upper-level node is completed.

[0613] According to an embodiment of the present disclosure, the slave node is also connected to the lower node via a power line carrier communication link and / or a wireless communication link, and the timing method further includes step S1140:

[0614] In step S1140, after the slave node completes the time calibration, it sends a time calibration beacon to the lower-layer node, so that the lower-layer node calibrates the local time according to the time calibration information in the received time calibration beacon.

[0615] In this step S1140, the role of the slave node is converted to the upper node of the lower node, and the lower node serves as the slave node in the above steps S1110~S1130. When the lower node calibrates the local time according to the calibration information in the received time calibration beacon, it can be completed by executing the above steps S1110~S1130.

[0616] In the time calibration method of the embodiment of the present invention, not only does the slave node need to receive the time calibration beacon from the upper node to perform its own time calibration, but after the slave node completes the time calibration, it also needs to assume the role of sending the time calibration beacon to the lower node, that is: each slave node will become the time calibration source for its lower node after completing its own time calibration. This process ensures that the time calibration information can be transmitted hierarchically along the network hierarchy, thereby forming a hierarchical transmission time calibration chain, and finally achieving time synchronization of all nodes in the entire power distribution network.

[0617] Fig.16 A flowchart of another time synchronization method for a power distribution network according to an embodiment of the present disclosure is shown. The time synchronization method is applied to a master node in the power distribution network, such as Fig.16 As shown, the time synchronization of other nodes in the power distribution network based on the designated node in the power distribution network includes the following steps S1610:

[0618] In step S1610, after the time calibration is completed, a time calibration beacon is sent to the lower-level slave node to realize the time calibration of the lower-level slave node; the time calibration beacon contains time calibration information, so that the lower-level slave node calibrates the local time according to the time calibration information in the time calibration beacon and the NTB time difference between the receiving time of the time calibration beacon and the zero-crossing time of the phase line where the lower-level slave node is located; wherein the time calibration information includes: the time value of the sending time of the time calibration beacon, and the NTB time difference between the sending time and the zero-crossing time of the phase line where the master node is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the master node.

[0619] The master node is a designated node in the power distribution network, or a node that is timed by the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to sync the designated node in the power distribution network in the following manner:

[0620] Obtain multiple timing times from multiple different timing sources;

[0621] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0622] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0623] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0624] The phase line where the master node is located includes three phase lines, and the NTB time difference includes: a first NTB time difference, a second NTB time difference, and a third NTB time difference, and the first NTB time difference, the second NTB time difference, and the third NTB time difference correspond to three different phase lines, respectively. In a specific example, the first NTB time difference corresponds to the A phase line, the second NTB time difference corresponds to the B phase line, and the third NTB time difference corresponds to the C phase line.

[0625] In addition, the time calibration beacon sent by the master node can be received not only by the lower-level slave nodes of the next level, but also by the slave nodes of other levels in the power distribution network. However, when the slave nodes of other levels are calibrating the time, when the slave node being calibrated and its upper-level node are in-phase nodes, the time calibration can be completed by using only the time calibration information in the time calibration beacon sent by the upper-level node. Only when the slave node being calibrated and its upper-level node are not in-phase nodes, the time calibration can be completed in combination with the time calibration information in the time calibration beacon sent by the master node.

[0626] Fig.17 A flowchart of another time synchronization method for a power distribution network according to an embodiment of the present disclosure is shown. The time synchronization method optimizes the clock synchronization mechanism in the power distribution network based on a reference beacon or a power line zero-crossing signal.

[0627] Specifically, the embodiments of the present disclosure involve timing nodes and timing nodes that are respectively in the same layer, adjacent layers or across layers, so that the layered timing scheme provided by the present disclosure does not rely on a strict hierarchical relationship. When they are in the same layer or adjacent layers, or when the timing nodes and timing nodes that are across layers are directly connected through a wireless communication link, the timing nodes and timing nodes communicate directly with each other, reducing the intermediate links and allowing the timing information to be exchanged faster, thereby reducing the risk of error accumulation and the timing delay caused by multi-level forwarding of timing information. In addition, by introducing the concept of reference nodes, the reference beacon sent by the reference node is received simultaneously by the time-corrected node and the time-correcting node as the reference moment, and the time values ​​recorded at the reference moment using the local clock are used as the first time correction information and the second time correction information respectively. The time correction is performed by using the deviation value between the first time correction information and the second time correction information. On the one hand, the existence of the reference node provides a reliable reference moment trigger source for the entire network. Even when some nodes in the network fail or the time deviation is large, the time correction can be quickly performed by re-receiving the reference beacon, thereby ensuring the time consistency of the entire system. On the other hand, traditional time correction methods may require complex protocols or algorithms to ensure time synchronization. After the introduction of the reference beacon, the node only needs to simply record the local time when the reference beacon is received, and perform time correction by comparing these time values, which greatly simplifies the time correction process and reduces the complexity of implementation. In addition, since the current waveform in the power line has a stable periodicity, the position of the zero-crossing point in the power line is relatively stable, predictable, highly repeatable, and easy to detect. By specifying the zero-crossing moment as the reference moment, the error caused by the node clock frequency deviation or phase difference can be eliminated, thereby improving the accuracy of time synchronization; and in large-scale substation networks, due to the large number of nodes and their wide distribution, traditional time synchronization methods may face problems such as signal coverage and communication delays. However, when using the power line's own zero-crossing signal for time synchronization, there is no need to consider these problems, because each node can directly sense these signals through the power line, which helps to achieve efficient and accurate time synchronization of large-scale networks, effectively improving the time synchronization accuracy of substation network nodes during clock synchronization, and improving the reliability and stability of the entire substation network.

[0628] Fig.18 FIG. 2 shows another schematic diagram of a power distribution network structure connection according to an embodiment of the present disclosure. Fig.18 As shown, the power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes ( Fig.18In the figure, 4 layers are taken as an example for explanation), the nodes in the power distribution network are connected through power line carrier communication links and / or wireless communication links; the multi-layer nodes in the power distribution network include time-checking nodes and time-checked nodes, and the time-checking nodes and time-checked nodes are respectively in the same layer, adjacent layers or across layers, and the time-checking nodes include: designated nodes in the power distribution network, or nodes that are time-checked through designated nodes in the power distribution network, and the designated nodes include multi-source fusion nodes or nodes other than the multi-source fusion nodes, and the multi-source fusion nodes support fusion timing of multiple different timing sources, and through the multi-source fusion nodes, the designated nodes in the power distribution network are time-checked based on the first intermediate value set determined in steps S510~540 above.

[0629] Different from the prior art, according to the embodiments of the present disclosure, the time-checking node is not limited to the master node CCO, and the time-checked node is not limited to PCO and STA. In specific applications, CCO can also be used as the time-checked node, and PCO and STA can also be used as the time-checking node. For example: Fig.13 In PCO 1-2 It can be used as a time calibration node to calibrate the CCO and STA nodes. 2-2 , STA 2-3 and PCO 2-2 Perform time calibration.

[0630] In addition, according to an embodiment of the present disclosure, the timing node and the node being timed are respectively in the same layer, adjacent layers or across layers, that is, the timing node and the node being timed can be in the same layer, for example: Fig.13 In, STA 1-1 With PCO 1-1 At the same layer, STA 1-1 Can be used as a time calibration node to check the PCO of the time-calibrated node 1-1 When calibrating, it can also be in adjacent layers or across layers, for example: PCO 1-1 It can be used as a time calibration node to check the time of the node STA 1-1 、PCO 2-1 , STA 3-1 and STA 3-2 Perform time calibration, where STA 1-1 With PCO 1-1 On the same layer, PCO 2-1 With PCO 1-1 In adjacent layers, STA 3-1 and STA 3-2 With PCO 1-1 Cross-layer.

[0631] In the technical solution disclosed in the present invention, by allowing direct time synchronization between nodes in the same layer, adjacent layers or across layers, the level of time synchronization signal transmission is reduced, thereby significantly shortening the time synchronization path. This decentralized or flattened time synchronization mechanism can greatly improve the time synchronization efficiency of the entire network system, especially in large or complex networks, the effect is particularly obvious. In addition, by simplifying the time synchronization path and reducing hierarchical dependencies, the overall complexity of the system is reduced, making network management and maintenance simpler and more efficient. At the same time, this solution can make more effective use of network resources. For example, when there is a time deviation between a PCO and multiple STAs or adjacent PCOs, the PCO can directly synchronize the time of these nodes without transiting through the CCO, thereby saving valuable network bandwidth and transmission time. Therefore, due to the reduction of the transmission delay of the time synchronization signal and the error accumulation in the intermediate links, this solution can improve the accuracy of time synchronization.

[0632] According to an embodiment of the present disclosure, the timing node and the node being timed are connected via a power line carrier communication link and / or a wireless communication link. When the timing node and the node being timed are across layers, in order to improve the timing efficiency, they can be connected via a wireless communication link.

[0633] In a specific application scenario, the power line carrier communication link includes but is not limited to: a high-speed power line carrier communication HPLC link, and the wireless communication link includes but is not limited to: a high-speed wireless HRF communication link.

[0634] The timing method is applied to the nodes to be timed in the power distribution network. Fig.17 As shown, the time synchronization of other nodes in the power distribution network based on the designated node in the power distribution network includes the following steps S1710~S1730:

[0635] In step S1710, first time synchronization information is obtained, where the first time synchronization information is a local clock timing value of the time-synchronized node obtained by the time-synchronized node at a reference time or a time having a preset relationship with the reference time.

[0636] In step S1720, second time synchronization information is obtained, where the second time synchronization information is a local clock timing value of the time synchronization node obtained by the time synchronization node at the reference time after the time synchronization is completed.

[0637] In step S1730, the time of the node to be timed is calibrated based on the first time calibration information and the second time calibration information.

[0638] Among them, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: the rising edge zero-crossing time and / or the falling edge zero-crossing time.

[0639] The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner:

[0640] Obtain multiple timing times from multiple different timing sources;

[0641] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0642] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0643] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0644] According to an embodiment of the present disclosure, when executing step S1720, that is, when acquiring the second timing information, the second timing information can be acquired by receiving a time calibration beacon sent by the timing node, wherein the time calibration beacon carries the second timing information.

[0645] After receiving the time calibration beacon sent by the timing node, the timing method further includes:

[0646] Recording a calibration time value, where the calibration time value is a time value measured by the local clock of the time-calibrated node corresponding to the moment of receiving the time calibration beacon;

[0647] The step of timing the node to be timed based on the first timing information and the second timing information includes: timing the node to be timed based on the first timing information, the second timing information and the calibration time scale value using the following formula:

[0648] ;

[0649] in, represents the first time synchronization information, represents the second timing information, represents the calibration time scale value, represents the local clock timing value of the node being calibrated after the calibration time value is calibrated, It is the time deviation between the first time calibration information and the second time calibration information, reflecting the difference between the clocks of the time calibration node and the time-calibrated node.

[0650] According to an embodiment of the present disclosure, when time calibration beacons sent by multiple timing nodes are received, the timing information in the time calibration beacon sent by the timing node that has the closest communication distance to the node being timed, has better communication quality, or has the lowest level among the multiple timing nodes is selected as the second timing information.

[0651] By selecting the time calibration node that has the shortest communication distance with the time-calibrated node for time calibration, the time source can be brought closer, and the transmission delay in the time transfer process can be reduced, thereby improving the time calibration accuracy.

[0652] By selecting a timing node with better communication quality for timing, you can reduce timing failures or errors caused by communication problems and improve the stability and reliability of the system.

[0653] When the power distribution network is calibrated from a low level to a high level according to the hierarchy, when the calibrated node at the high level is converted into a time calibration node after calibrating based on the time calibration node at the low level, in this case, based on the consideration of the additional clock error caused by the intermediate level-by-level timing, the clock accuracy of the time calibration node at the low level is higher than that of the time calibration node at the high level. Therefore, by selecting the lowest level timing node for time calibration, the additional clock error caused by the intermediate level-by-level timing can be avoided, thereby improving the time calibration accuracy.

[0654] According to an embodiment of the present disclosure, if time calibration beacons sent by multiple timing nodes are received, the multiple timing nodes include: a first timing node and a second timing node;

[0655] The step of calibrating the time of the node to be timed based on the first time calibration information and the second time calibration information includes:

[0656] When the first timing node has the shortest communication distance or the lowest level with the node being timed relative to the second timing node, the node being timed is timed based on the second timing information of the first timing node and the first timing information.

[0657] When the first timing node and the second timing node are at the same level, signal quality indicators of the first timing node and the second timing node when communicating with the source node of the upper level are respectively obtained, the corresponding communication quality is evaluated according to the signal quality indicators, and the timing node that meets the evaluation conditions among the first timing node and the second timing node is selected according to the communication quality evaluation result; the timing of the timing node being calibrated is performed based on the second timing information of the timing node that meets the evaluation conditions and the first timing information.

[0658] Based on the difference in reference time, the present disclosure provides two specific implementations: Specific implementation 1 and Specific implementation 2.

[0659] In the specific implementation mode 1, the concept of reference node is introduced, that is, the power distribution network includes three kinds of nodes, namely, the time-calibrated node, the time-calibrating node and the reference node. The reference moment is the moment when the time-calibrated node and the time-calibrating node simultaneously receive the reference beacon sent by the reference node. The first time-calibration information and the second time-calibration information are the time values ​​recorded in the local clock when the time-calibrating node and the time-calibrated node simultaneously receive the reference beacon sent by the same reference node. Among them, "simultaneously" means "at the same moment", but due to the difference between the local clocks of the time-calibrated node and the time-calibrating node, for the same moment, the local clock timing values ​​of the time-calibrated node and the time-calibrating node may be different.

[0660] The nodes in the power distribution network support dual-mode communication mode. The physical layers of the timing node, the timing node and the reference node have the same transmission and reception delay in the same communication mode. In this way, when the reference node sends a reference beacon to the timing node and the timing node at the same time, under the same physical transmission conditions (such as similar channel quality, signal strength, interference level, etc.), because the delay of physical layer processing (such as modulation, demodulation, encoding and decoding, etc.) is also the same, the reference beacon sent from the reference node can theoretically reach all receiving nodes in the same communication mode in the jurisdiction at the same time. In addition, the nodes in the power distribution network all have high-precision time timers to ensure the accuracy and stability of the internal time processing of the nodes. In this way, when the timing node and the timing node receive the reference beacon at the same time, the deviation between the time values ​​recorded by the local clock will accurately reflect the difference in the local timing of the timing node and the timing node. With the timing node as the timing standard, the timing node can be timed according to the deviation to achieve time synchronization with the timing node.

[0661] Fig.19 A schematic diagram of a time calibration process based on a reference beacon according to a specific embodiment 1 of the present disclosure is shown.

[0662] like Fig.19 As shown, STA0 is the reference node, STA1 is the time calibration node, and STA2-STA4 are the time-calibrated nodes, which have accurate clocks.

[0663] When starting the time calibration, first, the reference node STA0 uses the wireless or power line carrier communication mode to send a reference beacon to the time calibration node STA1 and the time calibration nodes STA2-STA4. Ignoring the transmission delay caused by the communication distance, the time-calibrated nodes STA2-STA4 record their own clock values ​​tt2-tt4 corresponding to the moment when receiving the reference beacon, and tt2, tt3 or tt4 is the first time calibration information. The time calibration node STA1 and the time-calibrated nodes STA2-STA4 receive the reference beacon Ts at the same moment, and the time calibration node STA1 records its own clock value tt1 corresponding to the moment, and tt1 is the second time calibration information.

[0664] At any subsequent time, the time calibration node STA1 sends a time calibration beacon to the time-calibrated nodes STA2-STA4, where the time calibration beacon carries the second time calibration information tt1. Since STA1 and STA4 are cross-layer, STA1 can directly send the time calibration beacon to STA4 through the wireless communication link, or it can calibrate STA4 through the STA2 relay. After receiving the time calibration beacon, the time-calibrated nodes STA2-STA4 obtain the second time calibration information tt1 from the time calibration beacon and record the calibration time values, which are: tr2, tr3 and tr4, respectively. Then, the time deviation between the two is calculated based on the locally recorded first time calibration information and the obtained second time calibration information tt1, for example:

[0665] For the time-calibrated node STA2, the time deviation between the first time calibration information and the second time calibration information is: tt2-tt1;

[0666] For the time-calibrated node STA3, the time deviation between the first time calibration information and the second time calibration information is: tt3-tt1;

[0667] For the time-calibrated node STA4, the time deviation between the first time calibration information and the second time calibration information is: tt4-tt1;

[0668] Finally, the time of the nodes STA2-STA4 being calibrated is calibrated according to the time deviations calculated by the nodes STA2-STA4 being calibrated.

[0669] For example, for the time-calibrated node STA2, the time calibration value ts2 is:

[0670] ts2 = tr2 - (tt2 - tt1);

[0671] For the time-calibrated node STA3, the time calibration value ts3 is:

[0672] ts3 = tr3 - (tt3 - tt1);

[0673] For the time-calibrated node STA4, the time calibration value ts4 is:

[0674] ts4 = tr4 - (tt4 - tt1);

[0675] Similarly, in another time calibration cycle, STA2 can also be used as a time calibration node to calibrate the time of the calibrated node STA4. At this time,

[0676] ts4=tr4-(tt4–tt2);

[0677] Fig. 20 FIG. 1 is a schematic diagram showing a time calibration process in a power distribution network according to a specific embodiment 1 of the present disclosure. Fig. 20 As shown, PCO2 can be used as the reference node for time calibration between CCO, PCO1, STA3, and STA4, and CCO can be used as the time calibration node to perform time calibration on the time-calibrated nodes PCO1, STA3, and STA4; CCO can be used as the reference node for time calibration between STA2, PCO1, and PCO2, and PCO1 can be used as the time calibration node to perform time calibration on the time-calibrated nodes STA2 and PCO2; STA3 can receive the time calibration beacon broadcast by PCO1 and PCO2, and select PCO2 with the closest communication distance to complete the time calibration.

[0678] In addition, the identities of the timing nodes and the timing nodes in the power distribution network can be converted to each other, for example: Fig. 20 As shown, in one time calibration cycle, PCO1 is the calibrated node and is calibrated by the calibrating node PCO2. In another time calibration cycle, since PCO1 has been calibrated, it can be used as a calibrating node to calibrate the calibrated nodes STA2 and PCO2.

[0679] Different from the specific embodiment 1, in the specific embodiment 2, the nodes in the power distribution network do not include the reference node, but only involve the timing node and the node to be timed, and the timing node and the node to be timed are both provided with a high-precision zero-crossing detection circuit, which has the ability to collect the power frequency zero-crossing points of the A / B / C three-phase line or the single-phase line and can record the time value of the zero-crossing moment of the three-phase or the phase line. At this time, the reference moment is a specified zero-crossing moment, and the specified zero-crossing moment includes: the rising edge zero-crossing moment and / or the falling edge zero-crossing moment. The specified zero-crossing moment can be one or more, and can be one, for example: the rising edge zero-crossing moment or the falling edge zero-crossing moment, or can be multiple, for example: the rising edge zero-crossing moment and the falling edge zero-crossing moment. In this way, the first timing information is the time value recorded by the local clock at one or more specified zero-crossing moments of the phase line where the timing node is located; the second timing information is the time value recorded by the local clock at one or more specified zero-crossing moments of the phase line where the timing node is located. Among them, the specified zero-crossing moment corresponding to the second timing information can be a zero-crossing moment that is exactly the same as the specified zero-crossing moment corresponding to the first timing information, or it can be a zero-crossing moment that has a preset relationship with the specified zero-crossing moment corresponding to the first timing information, for example: compared with the specified zero-crossing moment corresponding to the first timing information, it is separated by one or a known number of power frequency cycles, or it is a zero-crossing moment calculated based on a known phase difference.

[0680] When acquiring the first timing information, it can be performed before acquiring the second timing information, it can also be performed after acquiring the second timing information, or it can be performed simultaneously with acquiring the second timing information. Similarly, when acquiring the second timing information, the second timing information can be acquired by receiving a time calibration beacon sent by the timing node and acquiring the second timing information from the time calibration beacon.

[0681] After the time-corrected node obtains the first time correction information and the second time correction information, based on the fact that the time-corrected node and the time-correcting node may be located in different phase lines, and the voltage waveform periods in which the first time correction information and the second time correction information are located may also be different, even if the phase line and the voltage waveform period are the same, the first time correction information and the second time correction information may correspond to different zero-crossing points in the same voltage waveform period. Therefore, it is necessary to obtain the time values ​​recorded by the local clock at the same specified zero-crossing moment in the same voltage waveform period of the same phase line for the time correction node and the time-corrected node respectively according to the first time correction information and the second time correction information, and then calculate two time deviations, and finally use the time deviations to correct the time of the time-corrected node.

[0682] According to an embodiment of the present disclosure, when the node being calibrated is in phase with the timing node, the time value of the specified zero-crossing moment in the same voltage waveform period corresponding to the first timing information in the second timing information is obtained.

[0683] When the node being synchronized is in a different phase line from the timing node, the phase difference between the phase line where the node being synchronized and the timing node are located is obtained, and the time value of the specified zero-crossing moment in the same voltage waveform period of the same phase line corresponding to the first timing information in the second timing information is obtained based on the phase difference.

[0684] When there are multiple phase lines where the timing node is located, the time value of the specified zero-crossing moment corresponding to the phase line where the timing node is located in the first timing information is obtained, and the time value of the specified zero-crossing moment in the same voltage waveform period of the same phase line corresponding to the first timing information is obtained in the second timing information.

[0685] The time deviation between the first timing information and the second timing information corresponding to the same designated zero-crossing moment in the same voltage waveform cycle is calculated.

[0686] According to an embodiment of the present disclosure, if there are multiple designated zero-crossing moments, the average value of the time deviations of the same designated zero-crossing moments in the first timing information and the second timing information is calculated, and the time-synchronized node is timed using the average value of the time deviations.

[0687] Specifically, when the step of obtaining the first timing information and the second timing information corresponding to the same specified zero-crossing time in the same voltage waveform cycle is implemented, it is necessary to ensure that the time-corrected node and the timing node record data of the same voltage waveform cycle. This can be done in the following three ways:

[0688] Method 1: When the node to be timed is in the same phase line as the time-correcting node, since the node to be timed and the time-correcting node are in the same phase line, the voltage waveform cycles recorded by them are synchronized. At this time, first, by comparing the timestamps in the first time correction information and the second time correction information, the voltage waveform cycles recorded by them can be determined. Then, after determining the same voltage waveform cycle, find the designated zero-crossing moment (such as rising edge zero-crossing or falling edge zero-crossing) recorded in the first time correction information, and find the zero-crossing moment in the same voltage waveform cycle corresponding to the designated zero-crossing moment in the first time correction information in the second time correction information. This can be achieved by comparing whether the difference in the timestamps of the two is within an acceptable range. Finally, extract the time value corresponding to the designated zero-crossing moment in the first time correction information from the second time correction information, and obtain the same designated zero-crossing moment in the same voltage waveform cycle corresponding to the first time correction information and the second time correction information.

[0689] Method 2: When the node being calibrated and the timing node are in different phases, it is first necessary to know the phase difference between the phase line where the node being calibrated and the timing node are located, which can be obtained by measurement or pre-setting. Then, according to the phase difference, the time value in the second timing information is adjusted to match the voltage waveform period of the phase line where the node being calibrated is located. This may involve time addition and subtraction or time conversion based on the phase difference. Then, in the adjusted second timing information, find the zero-crossing moment in the same voltage waveform period corresponding to the specified zero-crossing moment in the first timing information. This can be achieved by comparing whether the time stamp difference between the two is within an acceptable range. Finally, extract the time value corresponding to the specified zero-crossing moment in the first timing information from the adjusted second timing information, and you can get the same specified zero-crossing moment in the same voltage waveform period corresponding to the first timing information and the second timing information.

[0690] Method 3: When there are multiple phase lines where the timing node is located, first determine the specified zero-crossing time corresponding to the phase line where the timing node is located according to the phase line information recorded in the first timing information. Then, find the zero-crossing time in the same voltage waveform cycle and the same phase line corresponding to the specified zero-crossing time in the first timing information in the second timing information. Finally, extract the time value corresponding to the specified zero-crossing time in the first timing information from the second timing information.

[0691] When the node being timed cannot be timed according to the time-calibrating node, it can be timed by clock self-maintenance. Specifically, the local clock error of the time-calibrated node after multiple time calibrations is estimated by least squares to generate a first error compensation parameter and the second error compensation parameter ;

[0692] According to the running values ​​corresponding to the i-2, i-1 and i moments of the local clock of the node being timed, And the first error compensation parameter and the second error compensation parameter Determine the time at time i of the local clock of the node being timed to be predicted and compensated ,in,

[0693] .

[0694] The "running value" mentioned above refers to the time value recorded or measured by the time-calibrated node at each specific time point (such as time i-2, i-1, i) under its internal clock source. These time values ​​reflect the time maintained by the time-calibrated node by its internal clock source (such as a crystal oscillator) without being calibrated by the time-calibrating node.

[0695] Fig.21A flowchart of another time synchronization method for a power distribution network according to an embodiment of the present disclosure is shown. The time synchronization method is applied to a time synchronization node in the power distribution network, such as Fig.21 As shown, the time calibration of other nodes in the power distribution network based on the designated node in the power distribution network includes the following steps S2110-2120:

[0696] In step S2110, after the time synchronization is completed, second time synchronization information is generated.

[0697] In step S2120, the second time synchronization information is sent to the time-synchronized node, so that the time-synchronized node obtains the second time synchronization information and calibrates the time of the time-synchronized node based on the first time synchronization information and the obtained second time synchronization information; the first time synchronization information is the local clock timing value of the time-synchronized node obtained by the time-synchronized node at a reference time or a time having a preset relationship with the reference time, and the second time synchronization information is the local clock timing value of the time-synchronizing node obtained by the time-synchronizing node at the reference time after the time synchronization is completed.

[0698] Wherein, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: a rising edge zero-crossing time and / or a falling edge zero-crossing time;

[0699] The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner:

[0700] Obtain multiple timing times from multiple different timing sources;

[0701] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0702] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0703] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0704] According to an embodiment of the present disclosure, the sending of the second timing information to the timing-corrected node includes:

[0705] A time calibration beacon is sent to the node to be time-calibrated directly or through a relay node, wherein the time calibration beacon carries the second time calibration information.

[0706] For step S430:

[0707] Fig. 22 A flowchart of a method for obtaining a timing cycle of a terminal wireless device connected to the node according to a time error coefficient and a maximum time synchronization tolerance threshold of the terminal wireless device according to an embodiment of the present disclosure is shown. Fig. 22 As shown, the following steps S2210~S2230 are included:

[0708] In step S2210, the time error coefficient of the terminal wireless device is obtained to form a time error coefficient set .

[0709] Among them, the time error coefficient set Denoted as: ; n represents the number of the terminal wireless devices, the time error coefficient of the i-th terminal wireless device is the time interval between two time calibrations performed by the node on the i-th terminal wireless device , and the internal clock time error of the ith terminal wireless device after the two calibrations , calculated by the following formula:

[0710] ,in, , is the internal clock time of the i-th terminal wireless device after the node performs the first time calibration on the i-th terminal wireless device, The internal clock time of the i-th terminal wireless device after the node performs the second time calibration on the i-th terminal wireless device.

[0711] In step S2220, a maximum time synchronization tolerance threshold of the terminal wireless device is obtained.

[0712] In step S2230, the maximum timing period of the terminal wireless device is calculated according to the maximum time synchronization tolerance threshold and the time error coefficient set to form a maximum timing period set.

[0713] Among them, the maximum timing cycle set is recorded as , the maximum timing period of the i-th terminal wireless device , is the maximum time synchronization tolerance threshold of the i-th terminal wireless device.

[0714] In step S2240, time slot allocation is performed according to the maximum timing period of the terminal wireless device to obtain the timing period of the terminal wireless device.

[0715] According to an embodiment of the present disclosure, the step of calibrating the time of the terminal wireless device according to the time calibration period includes:

[0716] Determine the optimization goal:

[0717]

[0718] in, The power consumption generated by the node calibrating the terminal wireless device; The channel time occupied by the node for calibrating the terminal wireless device, is a threshold of the channel occupation ratio for the node to perform time synchronization on the terminal wireless device, is the timing period of the i-th terminal wireless device.

[0719] Optimize the time synchronization period of the terminal wireless device according to the optimization target .

[0720] The terminal wireless device is time-calibrated according to the optimized time-calibration cycle.

[0721] The present invention avoids unnecessary frequent time synchronization operations by accurately calculating and utilizing the maximum clock tolerance period of each terminal wireless device for time synchronization, thereby reducing the energy consumption caused by time synchronization communications. This not only reduces the energy consumption of a single terminal wireless device, but also reduces the additional energy consumption caused by communication conflicts and retries by optimizing the overall communication mode of the network.

[0722] Fig.23 The structural block diagram of a time calibration device for a power distribution network according to an embodiment of the present disclosure is shown. The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The time calibration nodes and the time-calibrated nodes are respectively in the same layer, adjacent layers or across layers, and are connected via power line carrier communication links and / or wireless communication links. The time calibration device is arranged at the time-calibrated nodes in the power distribution network. Fig.23 As shown, the time calibration device 2300 includes: a first time calibration information acquisition module, which is configured to obtain first time calibration information, wherein the first time calibration information is the local clock timing value of the time calibrated node obtained by the time calibrated node at a reference time or a time having a preset relationship with the reference time; a second time calibration information acquisition module, which is configured to obtain second time calibration information, wherein the second time calibration information is the local clock timing value of the time calibrating node obtained by the time calibrating node at the reference time after completing the time calibration; the first time calibration module is configured to calibrate the time of the time calibrated node based on the first time calibration information and the second time calibration information.

[0723] Wherein, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: a rising edge zero-crossing time and / or a falling edge zero-crossing time; the time-correcting node is a specified node in the power distribution network, or a node that is time-corrected through the specified node, and the specified node includes a multi-source fusion node or a node other than the multi-source fusion node, and the multi-source fusion node supports fusion timing of multiple different timing sources, and the multi-source fusion node is used to time the specified node in the power distribution network in the following manner:

[0724] Obtain multiple timing times from multiple different timing sources;

[0725] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0726] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the multi-source fusion node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0727] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the multi-source fusion node is time-calibrated according to the first intermediate value set.

[0728] According to an embodiment of the present disclosure, the time calibration device further includes:

[0729] The clock self-maintaining module is configured to perform least square estimation on the local clock error after multiple calibrations to generate the first error compensation parameter and the second error compensation parameter ; According to the running values ​​corresponding to the local clock at time i-2, i-1 and i respectively And the first error compensation parameter and the second error compensation parameter Determine the predicted compensated local clock time at time i ,in,

[0730] .

[0731] Fig.24 The structural block diagram of another timing device for a power distribution network according to an embodiment of the present disclosure is shown. The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The timing nodes and the nodes to be timed are respectively in the same layer, adjacent layers or across layers, and are connected via a power line carrier communication link and / or a wireless communication link. The timing device is arranged at the timing node in the power distribution network, such as Fig.24 As shown, the time calibration device 2400 includes: a first time calibration information generating module, which is configured to generate second time calibration information after completing the time calibration; a first time calibration information sending module, which is configured to send the second time calibration information to the time-calibrated node, so that the time-calibrated node obtains the second time calibration information, and calibrates the time-calibrated node based on the first time calibration information and the obtained second time calibration information; the first time calibration information is the local clock timing value of the time-calibrated node obtained by the time-calibrated node at a reference time or a time having a preset relationship with the reference time, and the second time calibration information is the local clock timing value of the time-calibrating node obtained by the time-calibrating node at the reference time after completing the time calibration.

[0732] Among them, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: the rising edge zero-crossing time and / or the falling edge zero-crossing time.

[0733] The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner:

[0734] Obtain multiple timing times from multiple different timing sources;

[0735] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0736] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0737] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0738] Fig.25A structural block diagram of another time calibration device for a power distribution network according to an embodiment of the present disclosure is shown. The power distribution network adopts a hierarchical networking method and includes multiple layers of nodes, wherein the 0th layer node is a master node, and other layer nodes except the 0th layer node are slave nodes, wherein the slave nodes are connected to the upper layer nodes via a power line carrier communication link and / or a wireless communication link, and both the master node and the slave node are provided with a zero crossing detection circuit, and the time calibration device is provided at the slave node in the power distribution network, and the time calibration device 2500 includes: an upper layer node time calibration beacon receiving module, which is configured to receive a time calibration beacon sent by the upper layer node after the upper layer node of the slave node completes the time calibration, wherein the time calibration beacon contains time calibration information, and the time calibration information includes: the sending time of the time calibration beacon; The time value of the sending time and the NTB time difference between the sending time and the first zero-crossing time of the phase line where the upper node that sends the time calibration beacon is located, the time value of the sending time of the time calibration beacon is timed by the local clock of the upper node that sends the time calibration beacon; the NTB time difference acquisition module is configured to obtain the NTB time difference between the receiving time of the time calibration beacon and the second zero-crossing time of the phase line where the slave node is located; the slave node timing module is configured to perform timing on the slave node according to the timing information in the received time calibration beacon and the NTB time difference between the receiving time of the time calibration beacon and the second zero-crossing time of the phase line where the slave node is located.

[0739] The upper node of the slave node includes: the master node, the master node is a designated node in the power distribution network, or a node that performs time synchronization through the designated node, the designated node includes a multi-source fusion node or a node other than the multi-source fusion node, the multi-source fusion node supports fusion timing of multiple different timing sources, and the designated node in the power distribution network is synchronized in the following manner through the multi-source fusion node:

[0740] Obtain multiple timing times from multiple different timing sources;

[0741] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0742] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0743] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0744] According to an embodiment of the present disclosure, the slave node is also connected to the lower node via a power line carrier communication link and / or a wireless communication link, and the timing device further includes:

[0745] The slave node time calibration beacon sending module is configured to send a time calibration beacon to the lower node after the slave node completes the time calibration, so that the lower node can calibrate the local time according to the time calibration information in the received time calibration beacon.

[0746] Fig.26 A structural block diagram of another time calibration device for a power distribution network according to an embodiment of the present disclosure is shown. The power distribution network adopts a hierarchical networking method and includes multiple layers of nodes, the 0th layer node is a master node, and the other layer nodes except the 0th layer node are slave nodes. The master node is connected to the lower layer slave node through a power line carrier communication link and / or a wireless communication link. The master node and the slave node are both provided with a zero crossing detection circuit. The time calibration method is applied to the master node in the power distribution network. The time calibration device 2600 includes: a master node time calibration beacon sending module, which is configured to send a time calibration beacon to the lower layer slave node after completing the time calibration, so as to implement the lower layer slave node. The time calibration beacon contains the time calibration information so that the lower-level slave node can calibrate the local time according to the time calibration information in the time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the zero-crossing time of the phase line where the lower-level slave node is located; wherein the time calibration information includes: the time value of the sending time of the time calibration beacon, and the NTB time difference between the sending time and the zero-crossing time of the phase line where the master node is located, and the time value of the sending time of the time calibration beacon is based on the local clock of the master node.

[0747] The master node is a designated node in the power distribution network, or a node that is timed by the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to sync the designated node in the power distribution network in the following manner:

[0748] Obtain multiple timing times from multiple different timing sources;

[0749] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0750] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0751] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

[0752] Fig. 27A structural block diagram of a timing device for a multi-source fusion node according to an embodiment of the present disclosure is shown. The multi-source fusion node supports fusion timing of multiple different timing sources, and the timing device 2700 includes: a multi-source timing time acquisition module and a multi-source timing fusion module; the multi-source timing time acquisition module is configured to acquire multiple timing times from multiple different timing sources; the multi-source timing fusion module is configured to determine one or more first intermediate value sets based on the multiple timing times, and the first intermediate value set is determined based on the timing times from at least two different timing sources; when the first intermediate value set is multiple, the elements in the first intermediate value set are multiple, and the corresponding multiple second intermediate values ​​are determined based on the multiple first intermediate value sets; In the method, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from multiple second intermediate values ​​according to a preset rule; the first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of the designated node, and the designated node includes the multi-source fusion node or a node other than the multi-source fusion node; when the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the first intermediate value set is used to calibrate the time of the designated node.

[0753] According to an embodiment of the present disclosure, the acquiring of multiple timing times respectively from multiple different timing sources includes:

[0754] Acquire a preferred timing source set, wherein the preferred timing source set includes a plurality of different preferred timing sources, and the preferred timing source is a timing source that satisfies an evaluation condition and is screened out from the plurality of different timing sources by evaluating them;

[0755] Based on the preferred timing source set, multiple timing times respectively from the multiple different preferred timing sources are acquired.

[0756] According to an embodiment of the present disclosure, the time calibration device 2700 further includes:

[0757] The timing error monitoring module is configured to monitor the availability of each preferred timing source in the preferred timing source set; when the number of preferred timing sources with availability in the preferred timing source set does not meet a preset number threshold, the preferred timing source set is re-determined.

[0758] The present disclosure also provides a multi-source wide-area power distribution network hierarchical timing system, the timing system includes multiple nodes, at least one of which is a multi-source fusion node, and the multi-source fusion node supports fusion timing of multiple different timing sources; the timing system also includes a terminal wireless device, and the terminal wireless device is connected to the node in the timing system; wherein:

[0759] The multi-source fusion node is configured to perform time synchronization on a designated node in the time synchronization system in the following manner, wherein the designated node includes the multi-source fusion node or a node other than the multi-source fusion node:

[0760] Obtain multiple timing times from multiple different timing sources;

[0761] Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources;

[0762] When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value;

[0763] When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set;

[0764] The designated node is configured to perform time calibration on other nodes in the time calibration system after completing time calibration;

[0765] Among them, after completing the time calibration, the node in the time calibration system connected to the terminal wireless device obtains the time calibration period of the terminal wireless device according to the time error coefficient and the maximum time synchronization tolerance threshold of the terminal wireless device connected to the node; and calibrates the terminal wireless device according to the time calibration period.

[0766] The present disclosure also provides a chip, comprising a time calibration device as described in any one of the above device embodiments; or, comprising a memory and a processor; wherein the memory is used to store one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement a time calibration method as described in any one of the above method embodiments.

[0767] Fig.28 1 shows a structural block diagram of an electronic device according to an embodiment of the present disclosure. Fig.28 As shown, the electronic device includes a memory and a processor; wherein the memory is used to store one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the time synchronization method as described in any one of the above method embodiments.

[0768] The present disclosure also provides a computer-readable storage medium, which may be a computer-readable storage medium included in the electronic device or computer system in the above embodiment; or a computer-readable storage medium that exists independently and is not assembled into a device. The computer-readable storage medium stores one or more programs, and the programs are used by one or more processors to execute the time calibration method described in the present disclosure.

[0769] The present disclosure also provides a computer program product, including a computer program, wherein when the computer program is executed by a processor, the time calibration method described in any one of the present disclosure is implemented.

[0770] The above description is only a preferred embodiment of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present disclosure is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present disclosure (but not limited to) by each other.

Claims

1. A hierarchical timing method for a multi-source wide-area power distribution network, characterized in that: The power distribution network includes a plurality of nodes, at least one of which is a multi-source fusion node, and the multi-source fusion node supports fusion timing of a plurality of different timing sources; The power distribution network also includes a terminal wireless device, and the terminal wireless device is connected to a node in the power distribution network; the time synchronization method includes: The multi-source fusion node is used to calibrate the time of a designated node in the power distribution network in the following manner, wherein the designated node includes the multi-source fusion node or a node other than the multi-source fusion node: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set; After the designated node completes the time calibration, the other nodes in the power distribution network are time-calibrated based on the designated node; After the nodes in the power distribution network complete time synchronization, the time synchronization period of the terminal wireless device connected to the node is obtained according to the time error coefficient and the maximum time synchronization tolerance threshold of the terminal wireless device; the terminal wireless device is time synchronized according to the time synchronization period.

2. The time calibration method according to claim 1, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The nodes in the power distribution network are connected via power line carrier communication links and / or wireless communication links. The multiple layers of nodes in the power distribution network include master nodes and slave nodes. The 0th layer node in the power distribution network is the master node, and the other layer nodes except the 0th layer node are slave nodes. The master node and the slave node are both provided with a zero-crossing detection circuit. The upper layer nodes of the slave nodes include: the master node, the master node is a designated node in the power distribution network, or a node that is timed by the designated node in the power distribution network. The time calibrating of other nodes in the power distribution network based on the designated node includes: After the upper node of the slave node completes time calibration, a time calibration beacon sent by the upper node is received, wherein the time calibration beacon contains time calibration information, and the time calibration information includes: a time value of the sending time of the time calibration beacon, and an NTB time difference between the sending time and the first zero-crossing time of the phase line where the upper node sending the time calibration beacon is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the upper node sending the time calibration beacon; Obtaining the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located; The slave node is timed according to the time calibration information in the received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located.

3. The time calibration method according to claim 1, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The nodes in the power distribution network are connected via power line carrier communication links and / or wireless communication links. The multiple layers of nodes in the power distribution network include time calibration nodes and time-calibrated nodes. The time calibration nodes and time-calibrated nodes are respectively in the same layer, adjacent layers or across layers. The time calibration nodes include: designated nodes in the power distribution network, or nodes that are time-calibrated through designated nodes in the power distribution network. The time calibration of other nodes in the power distribution network based on the designated nodes includes: Acquire first time synchronization information, where the first time synchronization information is a local clock timing value of the time-synchronized node acquired by the time-synchronized node at a reference time or a time having a preset relationship with the reference time; Acquire second time synchronization information, where the second time synchronization information is a local clock timing value of the time synchronization node acquired by the time synchronization node at the reference time after completing the time synchronization; Performing time calibration on the time-calibrated node based on the first time calibration information and the second time calibration information; Among them, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: the rising edge zero-crossing time and / or the falling edge zero-crossing time.

4. The time calibration method according to claim 1, characterized in that: The step of acquiring the time calibration period of the terminal wireless device according to the time error coefficient of the terminal wireless device connected to the node and the maximum time synchronization tolerance threshold comprises: Obtain the time error coefficient of the terminal wireless device to form a time error coefficient set , recorded as: ; Where n represents the number of the terminal wireless devices, the time error coefficient of the i-th terminal wireless device is the time interval between two time calibrations performed by the node on the i-th terminal wireless device , and the internal clock time error of the ith terminal wireless device after the two calibrations , calculated by the following formula: ,in, , is the internal clock time of the i-th terminal wireless device after the node performs the first time calibration on the i-th terminal wireless device, The internal clock time of the i-th terminal wireless device after the node performs the second time calibration on the i-th terminal wireless device; Acquire a maximum time synchronization tolerance threshold of the terminal wireless device; Calculate the maximum timing cycle of the terminal wireless device according to the maximum time synchronization tolerance threshold and the time error coefficient set to form a maximum timing cycle set , where the maximum timing period of the i-th terminal wireless device is , is the maximum time synchronization tolerance threshold of the i-th terminal wireless device; Time slot allocation is performed according to the maximum timing cycle of the terminal wireless device to obtain the timing cycle of the terminal wireless device.

5. The time calibration method according to claim 4, characterized in that: The step of calibrating the time of the terminal wireless device according to the calibration period includes: Determine the optimization goal: in, The power consumption generated by the node calibrating the terminal wireless device; The channel time occupied by the node for calibrating the terminal wireless device, is a threshold of the channel occupation ratio for the node to perform time synchronization on the terminal wireless device, is the time calibration period of the i-th terminal wireless device; Optimize the time synchronization period of the terminal wireless device according to the optimization target ; The terminal wireless device is time-calibrated according to the optimized time-calibration cycle.

6. A time synchronization method for a multi-source fusion node, characterized in that: The multi-source fusion node supports fusion timing of multiple different timing sources, and the timing method includes: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; the first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of a designated node, and the designated node includes the multi-source fusion node or a node other than the multi-source fusion node; When there is one first intermediate value set, there are one or more elements in the first intermediate value set, and the first intermediate value set is used to calibrate the time of the designated node.

7. The time calibration method according to claim 6, characterized in that: The step of obtaining a plurality of timing times respectively from a plurality of different timing sources comprises: Acquire a preferred timing source set, wherein the preferred timing source set includes a plurality of different preferred timing sources, and the preferred timing source is a timing source that satisfies an evaluation condition and is screened out from the plurality of different timing sources by evaluating them; Based on the preferred timing source set, multiple timing times respectively from the multiple different preferred timing sources are acquired.

8. The time calibration method according to claim 7, characterized in that: The preferred timing source set is determined in the following manner: Acquire timing source evaluation indicators of the multiple different timing sources, wherein the timing source evaluation indicators are used to evaluate the availability of the timing sources; Constructing a utility function according to the timing source evaluation index, and using the utility function to calculate the utility values ​​of the multiple different timing sources; The multiple different timing sources are sorted from high to low according to the utility values, and according to the sorting result, a preset number of timing sources are selected to form the preferred timing source set.

9. The time calibration method according to claim 8, characterized in that: The timing source evaluation index includes: timing signal quality, timing accuracy, timing credibility and long-term availability; constructing a utility function according to the timing source evaluation index, and using the utility function to calculate the utility values ​​of the multiple different timing sources, including: Obtain the timing signal strength and / or the timing signal signal-to-noise ratio and / or the timing signal jitter rate of each timing source, and obtain the timing signal quality score of each timing source according to the timing signal strength and / or the timing signal signal-to-noise ratio and / or the timing signal jitter rate of each timing source; Obtain the timing accuracy of each timing source, and obtain the timing accuracy score of each timing source according to the timing accuracy of each timing source; By comparing the synchronization of the timing time of each timing source with the time pulse signal, the timing credibility of each timing source is judged, including: monitoring the frequency of the time pulse signal of each timing source, calculating the pulse deviation of each timing source, and obtaining the timing credibility score of each timing source according to the pulse deviation of each timing source; Counting the available time of each timing source within a preset time period, obtaining the long-term availability of each timing source according to the available time of each timing source within the preset time period, and obtaining the score of the long-term availability of each timing source according to the long-term availability of each timing source; The utility value of each timing source is calculated according to the following utility function constructed based on the score of the timing signal quality, the score of the timing accuracy, the score of the timing credibility and the score of the long-term availability: ； in, represents the utility value of the i-th timing source, represents the score of the timing signal quality of the i-th timing source, The weight representing the quality of the timing signal of the i-th timing source; represents the score of the timing accuracy of the i-th timing source, Represents the weight of the timing accuracy of the i-th timing source; Indicates the score of the timing reliability of the i-th timing source; Represents the weight of the timing credibility of the i-th timing source; represents the score of the long-term availability of the i-th timing source, Represents the weight of the long-term availability of the i-th timing source.

10. The time calibration method according to claim 8, characterized in that: The obtaining of timing source evaluation indicators of the plurality of different timing sources comprises: Obtain the current timing mode, where the current timing mode includes: a conventional timing mode, an emergency timing mode, a high-precision timing mode, a regional timing mode, and a backup timing mode; Obtain timing source evaluation indicators of the multiple different timing sources in the current timing mode.

11. The time calibration method according to claim 6, characterized in that: The determining a first intermediate value set according to the multiple timing times includes: Obtaining the timing accuracy and comprehensive credibility of each timing source; wherein the comprehensive credibility is determined based on the stability parameter, accuracy parameter and environmental factor of the corresponding timing source; Determine the timing accuracy range of each timing source according to the timing accuracy of each timing source; Determine the trust density of each timing source according to the timing accuracy interval and the comprehensive trustworthiness of each timing source, wherein the trust density is the comprehensive trustworthiness divided by the length of the timing accuracy interval; Normalize the trust density of each timing source; The multi-source fused timing time is calculated according to the timing time of each timing source and the credible density of each timing source after normalization, and the multi-source fused timing time forms the first intermediate value set.

12. The time calibration method according to claim 11, characterized in that: The multi-source fusion timing time is calculated according to the timing time of each timing source and the credible density of each timing source after normalization, including: The multi-source fusion timing time is calculated using the following formula: : ； in, is the timing time of the i-th timing source; is the normalized credible density of the i-th timing source, =1, n is the total number of timing sources; The first intermediate value set is used to calibrate the time of the designated node in the following manner, including: The multi-source fusion timing is used to calibrate the time of the designated node.

13. The time calibration method according to claim 7, characterized in that: The determining one or more first intermediate value sets according to the multiple timing times includes: Obtain the timing accuracy of each preferred timing source; Determine the timing range of each preferred timing source according to the timing accuracy and timing time of each preferred timing source; The intersection interval formed by the intersection of each timing range interval is determined by comparing the timing range intervals of each preferred timing source; wherein the two interval endpoints of the intersection interval form the first intermediate value set.

14. The time calibration method according to claim 13, characterized in that: When the first intermediate value set is one, the first intermediate value set is used to calibrate the time of the designated node in the following manner, including: Taking the average value of the two interval endpoints in the first intermediate value set as the multi-source fusion timing time, and using the multi-source fusion timing time to calibrate the time of the designated node; When there are multiple first intermediate value sets, determining multiple corresponding second intermediate values ​​according to the multiple first intermediate value sets respectively includes: The second intermediate value corresponding to each first intermediate value set is determined as follows: Determine the timing accuracy interval of each preferred timing source corresponding to the first intermediate value set according to the timing accuracy of each preferred timing source corresponding to the first intermediate value set; Determine the credibility density of each preferred timing source corresponding to the first intermediate value set according to the credibility and timing precision interval of each preferred timing source corresponding to the first intermediate value set, wherein the credibility density is the credibility divided by the length of the timing precision interval; The second intermediate value corresponding to the first intermediate value set is determined based on the maximum of the credible densities of the preferred timing sources corresponding to the first intermediate value set and the length of the intersection interval corresponding to the first intermediate value set, and the second intermediate value is the product of the maximum and the length of the intersection interval.

15. The time calibration method according to claim 14, characterized in that: The selecting a preferred second intermediate value from a plurality of second intermediate values ​​according to a preset rule comprises: selecting a maximum of the plurality of second intermediate values ​​as the preferred second intermediate value; The first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of the designated node in the following manner, including: The average value of two interval endpoints in the first intermediate value set corresponding to the preferred second intermediate value is used as the multi-source fusion timing time, and the multi-source fusion timing time is used to calibrate the time of the designated node.

16. The time calibration method according to claim 7, characterized in that: The time calibration method also includes: Monitoring the availability of each preferred timing source in the preferred timing source set; When the number of available preferred timing sources in the preferred timing source set does not meet a preset number threshold, the preferred timing source set is re-determined.

17. The time calibration method according to claim 16, characterized in that: The monitoring the availability of each preferred timing source in the preferred timing source set includes: The local clock error of the multi-source fusion node after the time calibration is estimated by least squares to generate a first error compensation parameter and the second error compensation parameter ; According to the running values ​​corresponding to the i-2, i-1 and i moments of the local clock of the multi-source fusion node, And the first error compensation parameter and the second error compensation parameter Get the time of the local clock i of the multi-source fusion node for prediction compensation ,in, ； The timing time of each preferred timing source in the preferred timing source set at the time i is obtained, and is recorded as: ; n represents the number of preferred timing sources in the preferred timing source set; The error between the timing time of each preferred timing source at time i in the preferred timing source set and the time of the local clock of the multi-source fusion node at time i of the prediction compensation is calculated respectively, wherein the timing time of the jth preferred timing source at time i is The error between the time at the local clock i of the multi-source fusion node compensated by the prediction Denoted as: ； It is determined whether each error is greater than a set error threshold. If so, it is determined that the corresponding preferred timing source is not available, and the corresponding preferred timing source is deleted from the preferred timing source set.

18. The time calibration method according to claim 6, characterized in that: The multi-source fusion node is in a first mobile communication network, the multiple different timing sources supported by the multi-source fusion node include a mobile communication air interface timing source and a preset reference timing source, and the acquiring of multiple timing times respectively from the multiple different timing sources includes: Obtaining the timing time of n historical moments corresponding to the preset reference timing source to form a first timing time sequence; wherein n is a positive integer greater than a preset threshold; Obtaining the timing time of the mobile communication air interface timing source corresponding to the n historical moments to form a second timing time sequence; The determining one or more first intermediate value sets according to the multiple timing times includes: Calculate the timing time deviation value between the first timing time sequence and the second timing time sequence corresponding to each historical moment to form an original timing time deviation value sequence; Based on each of the preset multiple window length values, respectively, the original timing time deviation value sequence is subjected to moving average filtering processing to generate multiple filtered timing time deviation value sequences corresponding to the multiple window length values, wherein the filtered timing time deviation value sequences form the first intermediate value set; Wherein, the filtered timing time deviation value sequence corresponding to the window length value is determined in the following manner: ， in, represents the ith sequence value in the filtered timing time deviation value sequence, m represents the window length value, Represents the ijth sequence value in the original timing time deviation value sequence.

19. The time calibration method according to claim 18, characterized in that: The determining a plurality of corresponding second intermediate values ​​according to the plurality of first intermediate value sets respectively comprises: The second intermediate value corresponding to each first intermediate value set is determined as follows: The Pearson coefficient p is calculated according to the original timing time deviation value sequence and the filtered timing time deviation value sequence corresponding to the first intermediate value set. The Pearson coefficient p is the second intermediate value corresponding to the first intermediate value set. The Pearson coefficient p is expressed by the following formula: ， in, It is represented as the i-th sequence value in the original timing time deviation value sequence, and are respectively the means of the original timing time deviation value sequence and the filtered timing time deviation value sequence, is the covariance of the original timing time deviation value sequence and the filtered timing time deviation value sequence, and are respectively the standard deviations of the original timing time deviation value sequence and the filtered timing time deviation value sequence.

20. The time calibration method according to claim 19, characterized in that: The selecting a preferred second intermediate value from a plurality of second intermediate values ​​according to a preset rule comprises: The multiple Pearson coefficients corresponding to the multiple window length values ​​are compared with the preset Pearson coefficient threshold value respectively, and the Pearson coefficient among the multiple Pearson coefficients that is closest to the preset Pearson coefficient threshold value is used as the preferred second intermediate value.

21. The time calibration method according to claim 20, characterized in that: The first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of the designated node in the following manner, including: The timing time optimization parameter is determined according to the nth sequence value in the filtered timing time deviation value sequence corresponding to the preferred second intermediate value and the air interface transmission delay corresponding to the nth historical moment of the mobile communication air interface timing source, wherein the timing time optimization parameter Use the following formula to express it: ， in, is the nth filtered timing deviation value sequence value, is the air interface transmission delay corresponding to the nth historical moment; The timing time optimization parameter is used to correct the timing time of the mobile communication air interface timing source, and the corrected timing time of the mobile communication air interface timing source is used to calibrate the time of the designated node.

22. The time calibration method according to claim 21, characterized in that: The method of using the timing time optimization parameter to correct the timing time of the mobile communication air interface timing source includes: Obtain the reference time and the time advance TA sent by the mobile communication air interface timing source; Determine the current air interface transmission delay according to the time advance TA; The sum of the current air interface transmission delay and the reference time sent by the mobile communication air interface timing source is used as the timing time of the mobile communication air interface timing source; The timing time of the mobile communication air interface timing source is corrected using the following formula based on the timing time optimization parameter: ， in, is the corrected timing time of the mobile communication air interface timing source, is the reference time sent by the mobile communication air interface timing source, is the current air interface transmission delay.

23. The time calibration method according to claim 21, characterized in that: The designated node includes: a mobile communication timing node, the mobile communication timing node is in the first mobile communication network or the second mobile communication network, and the mobile communication timing node supports the mobile communication air interface timing source; and the using the timing time optimization parameter to correct the timing time of the mobile communication air interface timing source includes: Sending the timing time optimization parameter to the mobile communication base station of the first mobile communication network, so that the mobile communication base station in the first mobile communication network carries the timing time optimization parameter to perform timing on the mobile communication timing node in the first mobile communication network, so that the mobile communication timing node in the first mobile communication network uses the timing time optimization parameter to correct the timing time of the mobile communication air interface timing source; And / or, so that the mobile communication base station of the first mobile communication network transmits the timing time optimization parameters back to the mobile communication access layer network, so that the mobile communication access layer network sends the timing time optimization parameters to the mobile communication base station in the second mobile communication network, so that the mobile communication base station in the second mobile communication network carries the timing time optimization parameters to time the mobile communication timing nodes in the second mobile communication network, so that the mobile communication timing nodes in the second mobile communication network use the timing time optimization parameters to correct the timing time of the mobile communication air interface timing source.

24. The time calibration method according to claim 23, characterized in that: When the first mobile communication network includes a plurality of multi-source fusion nodes, the timing method further includes: Sending the multiple timing time optimization parameters respectively determined by the multiple multi-source fusion nodes to the mobile communication base station in the first mobile communication network, so that the mobile communication base station in the first mobile communication network determines the final timing time optimization parameter according to the multiple timing time optimization parameters; Receive multiple timing time optimization parameters corresponding to the multiple multi-source fusion nodes sent by the mobile communication base station of the first mobile communication network; use the multiple timing time optimization parameters to correct the timing time of the mobile communication air interface timing source respectively to obtain the corresponding multiple corrected timing time of the mobile communication air interface timing source, calculate the difference between the multiple corrected timing time of the mobile communication air interface timing source and the timing time of the preset reference timing source respectively, obtain multiple errors corresponding to the multiple timing time optimization parameters, and send the multiple errors corresponding to the multiple timing time optimization parameters to the mobile communication base station of the first mobile communication network, so that after the mobile communication base station of the first mobile communication network receives the multiple errors corresponding to the multiple timing time optimization parameters sent by each multi-source fusion node, it weighted averages the errors calculated by the multiple multi-source fusion nodes using the same timing time optimization parameters to obtain multiple weighted average results, and sends the timing time optimization parameter of the multi-source fusion node corresponding to the smallest of the multiple weighted average results as the final timing time optimization parameter to the multiple multi-source fusion nodes; The final timing time optimization parameter sent by the mobile communication base station of the first mobile communication network is received, so as to use the final timing time optimization parameter to correct the timing time of the mobile communication air interface timing source.

25. The time calibration method according to claim 6, characterized in that: The multi-source fusion node is in a first mobile communication network, the multiple different timing sources supported by the multi-source fusion node include a mobile communication air interface timing source and a preset reference timing source, the mobile communication air interface timing source includes a cellular communication air interface timing and a direct communication timing, the first mobile communication network also includes a non-cellular timing node, the non-cellular timing node does not support cellular communication air interface timing and supports direct communication timing, the designated node is connected to the non-cellular timing node via a direct communication link, and the timing method also includes: After the designated node is timed, the delay measurement information is interacted with the non-cellular timing node through the Precision Time Protocol (PTP), so that the non-cellular timing node performs time synchronization based on the designated node.

26. A time calibration method for a power distribution network, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, the 0th layer node is a master node, and the nodes of other layers except the 0th layer node are slave nodes, the slave nodes are connected to the upper layer nodes through a power line carrier communication link and / or a wireless communication link, the master node and the slave node are both provided with a zero-crossing detection circuit, the timing method is applied to the slave nodes in the power distribution network, and the timing method includes: After the upper node of the slave node completes time calibration, a time calibration beacon sent by the upper node is received, wherein the time calibration beacon contains time calibration information, and the time calibration information includes: a time value of the sending time of the time calibration beacon, and an NTB time difference between the sending time and the first zero-crossing time of the phase line where the upper node sending the time calibration beacon is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the upper node sending the time calibration beacon; Obtaining the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located; Performing time calibration on the slave node according to the time calibration information in the received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located; The upper node of the slave node includes: the master node, the master node is a designated node in the power distribution network, or a node that performs time synchronization through the designated node, the designated node includes a multi-source fusion node or a node other than the multi-source fusion node, the multi-source fusion node supports fusion timing of multiple different timing sources, and the designated node in the power distribution network is synchronized in the following manner through the multi-source fusion node: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

27. The time calibration method according to claim 26, characterized in that: The first zero-crossing time and the second zero-crossing time are the same zero-crossing time; or There is a preset relationship between the first zero-crossing time and the second zero-crossing time.

28. The time calibration method according to claim 26, characterized in that: The slave node is also connected to the lower node via a power line carrier communication link and / or a wireless communication link, and the timing method further includes: After the slave node completes the time calibration, it sends a time calibration beacon to the lower-layer node, so that the lower-layer node calibrates the local time according to the time calibration information in the received time calibration beacon.

29. The time calibration method according to claim 26, characterized in that: The time calibration of the slave node according to the time calibration information in the received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located comprises: Obtaining a time calibration NTB time difference according to the NTB time difference in the time calibration information, wherein the time calibration NTB time difference corresponds to the phase line where the slave node is located; Calculate the time calibration beacon transmission delay time according to the time calibration NTB time difference and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located; Calculate the calibration time corresponding to the reception time of the time calibration beacon according to the transmission delay time of the time calibration beacon and the time value of the sending time in the calibration information; The time is calibrated using the calibration time corresponding to the reception time of the time calibration beacon.

30. The time calibration method according to claim 29, characterized in that: in, The NTB time difference includes: any one or more of a first NTB time difference, a second NTB time difference and a third NTB time difference; the first NTB time difference, the second NTB time difference and the third NTB time difference correspond to three different phase lines respectively, and the obtaining of the time calibration NTB time difference according to the NTB time difference in the time calibration information includes: When the NTB time difference in the timing information includes the first NTB time difference, the second NTB time difference and the third NTB time difference, the NTB time difference in the timing information corresponding to the phase line where the slave node is located is used as the timing NTB time difference; When the NTB time difference in the timing information is any one of the first NTB time difference, the second NTB time difference, and the third NTB time difference, and the upper node that sends the time calibration beacon and the slave node are in-phase nodes, the NTB time difference in the timing information is used as the timing NTB time difference; when the NTB time difference in the timing information is any one of the first NTB time difference, the second NTB time difference, and the third NTB time difference, and the upper node that sends the time calibration beacon and the slave node are not in-phase nodes, obtain two NTB time differences in the time calibration beacon sent by the master node that correspond to the phase line where the slave node is located and the phase line where the upper node that sends the time calibration beacon is located, obtain the difference between the two NTB time differences, and subtract the difference from the NTB time difference in the timing information to obtain the timing NTB time difference.

31. The time calibration method according to claim 29, characterized in that: The time calibration beacon transmission delay time is calculated using the following formula: ； The calibration time corresponding to the reception time of the time calibration beacon is calculated using the following formula: ； in, represents a calibration time corresponding to the reception moment of the time calibration beacon; Indicates the transmission delay time of the time calibration beacon; The time value representing the sending time in the time calibration information; represents the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located; is the power frequency cycle; n is the number of power frequency cycles spanned during the transmission of the time calibration beacon, n≥0, It is the time difference of the time calibration NTB.

32. A time calibration method for a power distribution network, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, the 0th layer node is a master node, and the nodes of other layers except the 0th layer node are slave nodes, the master node is connected to the lower layer slave node through a power line carrier communication link and / or a wireless communication link, and the master node and the slave node are both provided with a zero-crossing detection circuit. The timing method is applied to the master node in the power distribution network, and the timing method includes: After completing the time calibration, a time calibration beacon is sent to the lower-layer slave node to realize the time calibration of the lower-layer slave node; the time calibration beacon contains the time calibration information, so that the lower-layer slave node can calibrate the local time according to the time calibration information in the time calibration beacon and the NTB time difference between the receiving time of the time calibration beacon and the zero-crossing time of the phase line where the lower-layer slave node is located; wherein the time calibration information includes: the time value of the sending time of the time calibration beacon, and the NTB time difference between the sending time and the zero-crossing time of the phase line where the master node is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the master node; The master node is a designated node in the power distribution network, or a node that is timed by the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to sync the designated node in the power distribution network in the following manner: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

33. A time calibration method for a power distribution network, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The timing nodes and the nodes to be timed are respectively in the same layer, adjacent layers or across layers and are connected via a power line carrier communication link and / or a wireless communication link. The timing method is applied to the nodes to be timed in the power distribution network. The timing method includes: Acquire first time synchronization information, where the first time synchronization information is a local clock timing value of the time-synchronized node acquired by the time-synchronized node at a reference time or a time having a preset relationship with the reference time; Acquire second time synchronization information, where the second time synchronization information is a local clock timing value of the time synchronization node acquired by the time synchronization node at the reference time after completing the time synchronization; Performing time calibration on the time-calibrated node based on the first time calibration information and the second time calibration information; Wherein, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: a rising edge zero-crossing time and / or a falling edge zero-crossing time; The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

34. The time calibration method according to claim 33, characterized in that: When the reference time is a specified zero-crossing time, the first time calibration information is the time value recorded by the local clock at one or more specified zero-crossing times on the phase line where the time calibration node is located; the second time calibration information is the time value recorded by the local clock at one or more specified zero-crossing times on the phase line where the time calibration node is located; When the reference time is the time when the node being calibrated and the timing node simultaneously receive the reference beacon sent by the reference node, the physical layers of the timing node, the node being calibrated and the reference node have the same transmission and reception delay under the same communication mode, and the first timing information and the second timing information are respectively the time values ​​recorded using the local clock when the node being calibrated and the timing node simultaneously receive the reference beacon sent by the same reference node.

35. The time calibration method according to claim 33, characterized in that: The obtaining of the second timing information includes: Receive a time calibration beacon sent by the timing node, wherein the time calibration beacon carries the second timing information; and obtain the second timing information from the time calibration beacon.

36. The time calibration method according to claim 35, characterized in that: After receiving the time calibration beacon sent by the timing node, the timing method further includes: Recording a calibration time value, where the calibration time value is a time value measured by the local clock of the time-calibrated node corresponding to the moment of receiving the time calibration beacon; The step of timing the node to be timed based on the first timing information and the second timing information includes: timing the node to be timed based on the first timing information, the second timing information and the calibration time scale value using the following formula: ； in, represents the first time synchronization information, represents the second timing information, represents the calibration time scale value, Represents the local clock timing value of the node being calibrated after the calibration time value is calibrated.

37. The time calibration method according to claim 35, characterized in that: When time calibration beacons are received from multiple timing nodes, the timing information in the time calibration beacon sent by the timing node with the closest communication distance, better communication quality or lowest level to the timing node is selected as the second timing information.

38. The time calibration method according to claim 35, characterized in that: If time calibration beacons sent by multiple timing nodes are received, the multiple timing nodes include: a first timing node and a second timing node; The step of calibrating the time of the node to be timed based on the first time calibration information and the second time calibration information includes: When the first timing node has the shortest communication distance or the lowest level with the node to be timed relative to the second timing node, the node to be timed is timed based on the second timing information of the first timing node and the first timing information; When the first timing node and the second timing node are at the same level, signal quality indicators of the first timing node and the second timing node when communicating with the source node of the upper level are respectively obtained, the corresponding communication quality is evaluated according to the signal quality indicators, and the timing node that meets the evaluation conditions among the first timing node and the second timing node is selected according to the communication quality evaluation result; the timing of the timing node being calibrated is performed based on the second timing information of the timing node that meets the evaluation conditions and the first timing information.

39. The time calibration method according to claim 33, characterized in that: The time calibration method also includes: The local clock error of the node being timed after multiple time calibrations is estimated by least squares to generate a first error compensation parameter. and the second error compensation parameter ; According to the running values ​​corresponding to the i-2, i-1 and i moments of the local clock of the node being timed, And the first error compensation parameter and the second error compensation parameter Determine the time at time i of the local clock of the node being timed to be predicted and compensated ,in, 。 40. The time calibration method according to claim 33, characterized in that: When the reference time is a specified zero-crossing time, the step of calibrating the time of the time-calibrated node based on the first time calibration information and the second time calibration information includes: According to the first time calibration information and the second time calibration information, obtaining the time deviation recorded by the local clock at the designated zero-crossing moment in the same voltage waveform cycle of the same phase line between the time calibration node and the time-calibrated node; The time deviation is used to calibrate the time of the node being timed.

41. The time calibration method according to claim 40, characterized in that: The step of obtaining the time deviation of the timing node and the timing-corrected node corresponding to the designated zero-crossing moment in the same voltage waveform cycle of the same phase line according to the first timing information and the second timing information comprises: When the node to be timed is in phase with the time-setting node, obtaining the time value of the specified zero-crossing moment in the same voltage waveform cycle corresponding to the first time-setting information in the second time-setting information; When the node being timed is out of phase with the time calibration node, the phase difference between the phase line where the node being timed is located and the phase line where the time calibration node is located is obtained, and according to the phase difference, the time value of the specified zero-crossing moment in the same phase line and the same voltage waveform period corresponding to the first time calibration information in the second time calibration information is obtained; When there are multiple phase lines where the timing node is located, according to the time value of the specified zero-crossing moment corresponding to the phase line where the timing node is located in the first timing information, obtain the time value of the specified zero-crossing moment in the same voltage waveform period of the same phase line corresponding to the first timing information in the second timing information; The time deviation between the first timing information and the second timing information corresponding to the same designated zero-crossing moment in the same voltage waveform cycle is calculated.

42. The time calibration method according to claim 41, characterized in that: If there are multiple designated zero-crossing moments, the time calibration method further includes: The average value of the time deviations of the same designated zero-crossing moment in the first timing information and the second timing information is calculated, and the time of the node being timed is calibrated using the average value of the time deviations.

43. A time calibration method for a power distribution network, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The timing nodes and the nodes to be timing-calibrated are respectively in the same layer, adjacent layers or across layers and are connected via a power line carrier communication link and / or a wireless communication link. The timing method is applied to the timing nodes in the power distribution network. The timing method includes: After completing the time calibration, generating the second time calibration information; The second time synchronization information is sent to the time-synchronized node, so that the time-synchronized node obtains the second time synchronization information, and performs time synchronization on the time-synchronized node based on the first time synchronization information and the obtained second time synchronization information; the first time synchronization information is the local clock timing value of the time-synchronized node obtained by the time-synchronized node at a reference time or a time having a preset relationship with the reference time, and the second time synchronization information is the local clock timing value of the time-synchronizing node obtained by the time-synchronizing node at the reference time after the time synchronization is completed; Wherein, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: a rising edge zero-crossing time and / or a falling edge zero-crossing time; The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

44. The time calibration method according to claim 43, characterized in that: The sending the second timing information to the timing-corrected node includes: A time calibration beacon is sent to the node to be time-calibrated directly or through a relay node, wherein the time calibration beacon carries the second time calibration information.

45. A time calibration device for a power distribution network, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The timing nodes and the nodes to be timed are respectively in the same layer, adjacent layers or across layers, and are connected through power line carrier communication links and / or wireless communication links. The timing device is arranged at the nodes to be timed in the power distribution network, and the timing device includes: A first time synchronization information acquisition module is configured to acquire first time synchronization information, wherein the first time synchronization information is a local clock timing value of the time-synchronized node acquired by the time-synchronized node at a reference time or a time having a preset relationship with the reference time; A second time synchronization information acquisition module is configured to acquire second time synchronization information, where the second time synchronization information is a local clock timing value of the time synchronization node acquired by the time synchronization node at the reference time after completing the time synchronization; A first timing module is configured to perform timing on the timing-corrected node based on the first timing information and the second timing information; Wherein, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: a rising edge zero-crossing time and / or a falling edge zero-crossing time; The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the multi-source fusion node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the multi-source fusion node is time-calibrated according to the first intermediate value set.

46. ​​The time setting device according to claim 45, characterized in that: The time calibration device also includes: The clock self-maintaining module is configured to perform least square estimation on the local clock error after multiple calibrations to generate the first error compensation parameter and the second error compensation parameter ; According to the running values ​​corresponding to the local clock at time i-2, i-1 and i respectively And the first error compensation parameter and the second error compensation parameter Determine the predicted compensated local clock time at time i ,in, 。 47. A time calibration device for a power distribution network, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes. The timing nodes and the nodes to be timing-calibrated are respectively in the same layer, adjacent layers or across layers, and are connected through power line carrier communication links and / or wireless communication links. The timing device is arranged at the timing node in the power distribution network, and the timing device includes: The first time synchronization information generating module is configured to generate the second time synchronization information after completing the time synchronization; A first time synchronization information sending module is configured to send the second time synchronization information to the time-synchronized node, so that the time-synchronized node obtains the second time synchronization information and performs time synchronization on the time-synchronized node based on the first time synchronization information and the obtained second time synchronization information; the first time synchronization information is a local clock timing value of the time-synchronized node obtained by the time-synchronized node at a reference time or a time having a preset relationship with the reference time, and the second time synchronization information is a local clock timing value of the time-synchronizing node obtained by the time-synchronizing node at the reference time after the time synchronization is completed; Wherein, the reference time is the time when the time-corrected node and the time-correcting node simultaneously receive the reference beacon sent by the reference node; and / or, the time-correcting node and the time-corrected node are both provided with a zero-crossing detection circuit, and the reference time is a specified zero-crossing time, and the specified zero-crossing time includes: a rising edge zero-crossing time and / or a falling edge zero-crossing time; The timing node is a designated node in the power distribution network, or a node that performs timing through the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to perform timing on the designated node in the power distribution network in the following manner: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

48. A time calibration device for a multi-source fusion node, characterized in that: The multi-source fusion node supports the fusion of multiple different timing sources, and the timing device includes: a multi-source timing time acquisition module and a multi-source timing fusion module; The multi-source timing time acquisition module is configured to acquire multiple timing times from multiple different timing sources; The multi-source timing fusion module is configured to determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value set is determined according to the timing times from at least two different timing sources; when there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; the first intermediate value set corresponding to the preferred second intermediate value is used to calibrate the time of a designated node, wherein the designated node includes the multi-source fusion node or a node other than the multi-source fusion node; when there is one first intermediate value set, there are one or more elements in the first intermediate value set, and the first intermediate value set is used to calibrate the time of the designated node.

49. The time setting device according to claim 48, characterized in that: The step of obtaining a plurality of timing times respectively from a plurality of different timing sources comprises: Acquire a preferred timing source set, wherein the preferred timing source set includes a plurality of different preferred timing sources, and the preferred timing source is a timing source that satisfies an evaluation condition and is screened out from the plurality of different timing sources by evaluating them; Based on the preferred timing source set, multiple timing times respectively from the multiple different preferred timing sources are acquired.

50. The time setting device according to claim 49, characterized in that: The time calibration device also includes: The timing error monitoring module is configured to monitor the availability of each preferred timing source in the preferred timing source set; when the number of preferred timing sources with availability in the preferred timing source set does not meet a preset number threshold, the preferred timing source set is re-determined.

51. A time calibration device for a power distribution network, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, the 0th layer node is a master node, and the nodes of other layers except the 0th layer node are slave nodes, the slave nodes are connected to the upper layer nodes through a power line carrier communication link and / or a wireless communication link, the master node and the slave node are both provided with a zero-crossing detection circuit, the timing device is arranged at the slave node in the power distribution network, and the timing device includes: The upper node time calibration beacon receiving module is configured to receive the time calibration beacon sent by the upper node after the upper node of the slave node completes the time calibration, wherein the time calibration beacon contains the time calibration information, and the time calibration information includes: the time value of the sending time of the time calibration beacon, and the NTB time difference between the sending time and the first zero-crossing time of the phase line where the upper node sending the time calibration beacon is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the upper node sending the time calibration beacon; An NTB time difference acquisition module is configured to acquire an NTB time difference between a reception time of the time calibration beacon and a second zero-crossing time of the phase line where the slave node is located; A slave node timing module is configured to perform timing on the slave node according to the timing information in the received time calibration beacon and the NTB time difference between the reception time of the time calibration beacon and the second zero crossing time of the phase line where the slave node is located; The upper node of the slave node includes: the master node, the master node is a designated node in the power distribution network, or a node that performs time synchronization through the designated node, the designated node includes a multi-source fusion node or a node other than the multi-source fusion node, the multi-source fusion node supports fusion timing of multiple different timing sources, and the designated node in the power distribution network is synchronized in the following manner through the multi-source fusion node: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

52. The time setting device according to claim 51, characterized in that: The slave node is also connected to the lower node via a power line carrier communication link and / or a wireless communication link, and the timing device further includes: The slave node time calibration beacon sending module is configured to send a time calibration beacon to the lower node after the slave node completes the time calibration, so that the lower node can calibrate the local time according to the time calibration information in the received time calibration beacon.

53. A time calibration device for a power distribution network, characterized in that: The power distribution network adopts a hierarchical networking mode and includes multiple layers of nodes, the 0th layer node is a master node, and the nodes of other layers except the 0th layer node are slave nodes, the master node is connected to the lower layer slave node through a power line carrier communication link and / or a wireless communication link, the master node and the slave node are both provided with a zero-crossing detection circuit, the time calibration device is arranged at the master node in the power distribution network, and the time calibration device includes: The master node time calibration beacon sending module is configured to send a time calibration beacon to the lower-layer slave node after completing the time calibration, so as to realize the time calibration of the lower-layer slave node; the time calibration beacon contains the time calibration information, so that the lower-layer slave node can calibrate the local time according to the time calibration information in the time calibration beacon and the NTB time difference between the receiving time of the time calibration beacon and the zero-crossing time of the phase line where the lower-layer slave node is located; wherein the time calibration information includes: the time value of the sending time of the time calibration beacon, and the NTB time difference between the sending time and the zero-crossing time of the phase line where the master node is located, and the time value of the sending time of the time calibration beacon is timed by the local clock of the master node; The master node is a designated node in the power distribution network, or a node that is timed by the designated node. The designated node includes a multi-source fusion node or a node other than the multi-source fusion node. The multi-source fusion node supports fusion timing of multiple different timing sources. The multi-source fusion node is used to sync the designated node in the power distribution network in the following manner: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set.

54. A multi-source wide-area power distribution network hierarchical timing system, characterized in that: The timing system includes a plurality of nodes, at least one of which is a multi-source fusion node, and the multi-source fusion node supports fusion timing of a plurality of different timing sources; the timing system also includes a terminal wireless device, and the terminal wireless device is connected to the node in the timing system; wherein: The multi-source fusion node is configured to perform time synchronization on a designated node in the time synchronization system in the following manner, wherein the designated node includes the multi-source fusion node or a node other than the multi-source fusion node: Obtain multiple timing times from multiple different timing sources; Determine one or more first intermediate value sets according to the multiple timing times, wherein the first intermediate value sets are determined according to the timing times from at least two different timing sources; When there are multiple first intermediate value sets, there are multiple elements in the first intermediate value set, and multiple corresponding second intermediate values ​​are determined according to the multiple first intermediate value sets respectively; wherein, for each first intermediate value set, the second intermediate value is determined according to the credibility of the timing source corresponding to the first intermediate value set, or according to the timing time deviation value between the timing times of the timing sources corresponding to the first intermediate value set; a preferred second intermediate value is selected from the multiple second intermediate values ​​according to a preset rule; and the designated node is timed according to the first intermediate value set corresponding to the preferred second intermediate value; When the first intermediate value set is one, the elements in the first intermediate value set are one or more, and the designated node is timed according to the first intermediate value set; The designated node is configured to perform time calibration on other nodes in the time calibration system after completing time calibration; Among them, after completing the time calibration, the node in the time calibration system connected to the terminal wireless device obtains the time calibration period of the terminal wireless device according to the time error coefficient and the maximum time synchronization tolerance threshold of the terminal wireless device connected to the node; and calibrates the terminal wireless device according to the time calibration period.

55. A chip, characterized in that: A time calibration device comprising any one of claims 45 to 53; or, comprising a memory and a processor; wherein the memory is used to store one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the time calibration method according to any one of claims 1 to 44.

56. An electronic device, characterized in that: It comprises a memory and a processor; wherein the memory is used to store computer instructions, wherein the computer instructions are executed by the processor to implement the time calibration method described in any one of claims 1 to 44.

57. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by the processor, the time calibration method described in any one of claims 1 to 44 is implemented.

58. A computer program product comprising computer instructions, characterized in that: When the computer instructions are executed by the processor, the time calibration method described in any one of claims 1 to 44 is implemented.

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