High-precision time synchronization method and device applied to electric energy metering system

Abstract

The invention provides a high-precision time synchronization method and device applied to an electric energy metering system. Belongs to the technical field of power system time synchronization. The method comprises the following steps: a concentrator performs time comparison interaction with a reference time station through a satellite common-view technology, obtains a time difference of local time of the concentrator relative to the reference time station, and outputs standard time; the power line carrier master station obtains standard time and transmits the standard time to the power line carrier terminal station in a power line carrier communication mode; and the power line carrier terminal station determines the time deviation of the power line carrier terminal station relative to the power line carrier master station by adopting a bidirectional message time synchronization mechanism, and compensates an internal clock according to the time deviation so as to realize time synchronization. According to the method, the time consistency of the electric energy metering devices in the transformer area can be improved under the existing electric energy metering system architecture, the synchronous state can be mastered and monitored in a centralized mode, and the high-precision time synchronization and operation management requirements are met.

Description

Technical Field

[0001] This invention belongs to the field of power system time synchronization technology, and in particular relates to a high-precision time synchronization method and device for use in power metering systems. Background Technology

[0002] Against the backdrop of the ongoing construction of smart grids and the reform of the power market, electricity metering devices are widely used in time-of-use pricing, electricity trading metering, load analysis, and event sequence determination. Their time consistency directly affects the accuracy of metering and the fairness of the business.

[0003] With the increasing sophistication of applications, the demand for time accuracy has risen from minutes to milliseconds, and in some scenarios, even microsecond-level synchronization is required. In existing power systems, electricity metering devices are typically connected to a master station via concentrators. The master station uses a Global Navigation Satellite System (GNSS, such as GPS or BeiDou) as its time reference and transmits time via high-speed power line communication (HPLC). Current time synchronization largely relies on concentrators broadcasting time synchronization commands to electricity meters within the distribution area at fixed intervals. This method is susceptible to grid noise, load fluctuations, unstable communication link quality, and differences in the number and distribution of electricity meters, leading to delays and fluctuations during command transmission and forwarding. This results in increased time deviations at remote electricity meters and decreased time consistency between devices.

[0004] Existing technologies typically improve synchronization by increasing the synchronization frequency, extending the communication window, or concentrating synchronization during specific time periods. They may also combine multiple communication methods for time distribution. However, in practical deployments, a trade-off must be struck between communication resource consumption, system complexity, and operational stability. Furthermore, the effectiveness is uncertain when the distribution area is large or communication conditions are complex. In addition, when internal clock drift occurs or clock jumps are caused by power outages or restorations, deviations may go undetected for extended periods, impacting time-of-use pricing, event analysis, and maintenance management. Overall, existing time synchronization and monitoring technologies remain limited in terms of synchronization accuracy stability, status awareness, and large-scale adaptability. Summary of the Invention

[0005] The purpose of this invention is to provide a high-precision time synchronization method and device for use in power metering systems. This method and device can improve the time consistency of power metering devices within a distribution area under the existing power metering system architecture, and enable centralized control and monitoring of the synchronization status, thereby meeting the requirements for high-precision time synchronization and operation management.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a high-precision time synchronization method for an electricity metering system, the electricity metering system comprising a reference time station, a concentrator, and an electricity metering device, the method comprising: The concentrator interacts with the reference time station through satellite common-view technology to obtain the time difference between the concentrator's local time and the reference time station, and compensates the internal clock of the concentrator based on the time difference to output standard time. The power line carrier master station deployed on the concentrator obtains the standard time and transmits the standard time to the power line carrier terminal stations deployed on the power metering devices within the distribution area via power line carrier communication. The power line carrier terminal station uses a two-way message time synchronization mechanism to determine the time deviation between the power line carrier terminal station and the power line carrier master station, and compensates the internal clock according to the time deviation to achieve time synchronization.

[0007] Furthermore, high-precision time synchronization methods for electricity metering systems also include: The power line carrier terminal station reports the time deviation to the power line carrier master station; The power line carrier master station summarizes the time deviations of multiple power line carrier terminal sites within the distribution area and provides the summary results to the concentrator. The concentrator uploads the aggregated results to the data server via the mobile communication network. The data server receives and stores the aggregated results to monitor the synchronization status of each power line carrier terminal site within the distribution area.

[0008] Furthermore, the steps for determining the time deviation between the power line carrier terminal station and the power line carrier master station include: The power line carrier master station sends a synchronization message to the power line carrier terminal station, and the power line carrier master station records the transmission time of the synchronization message as t1 based on the master station's local clock. After sending the synchronization message, the power line carrier master station sends a follow-up message to the power line carrier terminal station, and carries the sending time t1 in the follow-up message; The power line carrier terminal station receives the synchronization message, and records the reception time of the synchronization message as t2 on its local clock, and receives the follow-up message to obtain the transmission time t1; The power line carrier terminal station sends a delay request message to the power line carrier master station, and the power line carrier terminal station records the time of transmission of the delay request message as t3 based on the terminal's local clock. The power line carrier master station receives the delay request message and records the reception time of the delay request message as t4 based on the master station's local clock. The power line carrier master station sends a delay response message to the power line carrier terminal station and carries the reception time t4 in the delay response message; The power line carrier terminal station receives the delay response message to obtain the reception time t4, and calculates the time offset based on the following formula: Offset = 1 / 2 × [(t2) t1)+(t3 t4)).

[0009] Furthermore, the steps by which the concentrator interacts with the reference time station via satellite common-view technology for time comparison include: The concentrator generates a local global satellite navigation system universal time transfer standard format file on the concentrator side; The reference time station generates a global satellite navigation system universal time transfer standard format file on the reference time station side and sends it to the concentrator through the mobile communication network; The concentrator receives the Global Navigation Satellite System General Time Transfer Standard Format file from the reference time station and performs a difference operation between the local Global Navigation Satellite System General Time Transfer Standard Format file and the reference time station's Global Navigation Satellite System General Time Transfer Standard Format file to obtain the time difference. The concentrator compensates for the internal clock based on the time difference and outputs a time-frequency signal as the standard time after compensation.

[0010] Furthermore, the steps for transmitting standard time to power line carrier terminal sites deployed on electricity metering devices within the distribution area via power line carrier communication include: The power line carrier master station acquires the standard time and modulates the standard time into a carrier signal. The power line carrier master station loads the carrier signal onto the A-phase, B-phase, and C-phase power lines for transmission. Power line carrier terminal sites extract carrier signals from power lines and demodulate them to obtain standard time.

[0011] In a second aspect, the present invention provides a high-precision time synchronization device for use in an electricity metering system. The high-precision time synchronization device is deployed in the electricity metering system, which includes a reference time station, a concentrator, and an electricity metering device. The high-precision time synchronization device includes: The concentrator is used to compare and interact with the reference time station through satellite common-view technology, obtain the time difference between the concentrator's local time and the reference time station, and compensate the internal clock of the concentrator based on the time difference to output standard time. The power line carrier master station is deployed on the concentrator to obtain the standard time and transmit the standard time to the power line carrier terminal stations deployed on the power metering devices in the distribution area via power line carrier communication. Power line carrier terminal stations are deployed on power metering devices. They are used to determine the time deviation between the power line carrier terminal station and the power line carrier master station using a two-way message time synchronization mechanism, and to compensate the internal clock based on the time deviation to achieve time synchronization.

[0012] Furthermore, the power line carrier terminal station is also used to report time deviations to the power line carrier master station; The power line carrier master station is also used to summarize the time deviations of multiple power line carrier terminal sites within the distribution area and provide the summary results to the concentrator. The concentrator is also used to upload the aggregated results to the data server via the mobile communication network, so that the data server can receive and store them to monitor the synchronization status of each power line carrier terminal site in the distribution area.

[0013] Furthermore, the power line carrier master station is also used to send synchronization messages to the power line carrier terminal stations, and records the sending time of the synchronization message as t1 based on the master station's local clock; After sending the synchronization message, the power line carrier master station is also used to send a follow-up message to the power line carrier terminal station, and carries the sending time t1 in the follow-up message; The power line carrier terminal site is also used to receive synchronization messages, record the reception time of the synchronization message as t2 based on the terminal's local clock, and receive follow-up messages to obtain the transmission time t1; The power line carrier terminal site is also used to send delay request messages to the power line carrier master station, and records the sending time of the delay request message as t3 based on the local clock of the terminal. The power line carrier master station is also used to receive delay request messages and record the reception time of the delay request message as t4 based on the master station's local clock. The power line carrier master station is also used to send delay response messages to power line carrier terminal stations, and carries the reception time t4 in the delay response messages; The power line carrier terminal station is also used to receive delay response messages to obtain the reception time t4, and to calculate the time offset based on the following formula: Offset = 1 / 2 × [(t2) t1)+(t3 t4)).

[0014] Furthermore, the concentrator is also used to generate local global satellite navigation system universal time transfer standard format files on the concentrator side; The reference time station is also used to generate a global satellite navigation system universal time transfer standard format file on the reference time station side, and send it to the concentrator via a mobile communication network; The concentrator is also used to receive the Global Navigation Satellite System Universal Time Transfer Standard (GNSSUP) format file from the reference time station, and to perform difference processing on the local GNSSUP format file and the GNSSUP format file from the reference time station to obtain the time difference. Based on the time difference, the internal clock is compensated and the standard time is output.

[0015] Furthermore, the power line carrier master station is also used to modulate the standard time into a carrier signal and load the carrier signal onto the A-phase, B-phase, and C-phase power lines for transmission. Power line carrier terminal sites are also used to extract carrier signals from power lines and demodulate them to obtain standard time.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention introduces satellite common-view technology at the concentrator side for time tracing of the reference time station and combines power line carrier communication and a two-way message time synchronization mechanism within the distribution area to achieve a complete synchronization process from time reference acquisition, time distribution within the distribution area, to time compensation at the terminal side. Compared with existing time synchronization methods that mainly rely on one-way broadcast time synchronization, this invention does not depend on issuing time synchronization commands at fixed intervals. Instead, it accurately calculates time deviations through two-way message interaction between terminal stations and the master station, thereby effectively eliminating the impact of random delays in power line transmission on synchronization accuracy. This improves the time synchronization accuracy of electricity metering devices within the distribution area from the second and millisecond levels to a higher level, meeting the application scenarios with high time consistency requirements, such as time-of-use billing, event sequence analysis, and fault location.

[0017] 2. By setting up a mechanism where time deviations are reported by power line carrier terminal sites, centrally aggregated by the power line carrier master station, and uniformly uploaded to the data server by the concentrator, this invention builds a centralized monitoring capability for synchronization status based on time synchronization. Unlike the traditional open-loop method where time synchronization ends once completed, this invention can continuously acquire the actual time deviations of each terminal site within the distribution area, enabling visualization and traceable management of synchronization effects. In the event of terminal clock drift, abnormal jumps, or synchronization failures, problematic devices can be quickly located through server-side data, avoiding manual troubleshooting of each device, improving operational efficiency, and reducing maintenance costs in large-scale distribution area scenarios.

[0018] 3. This invention reuses existing power line carrier communication networks and the mobile communication capabilities of concentrators to achieve high-precision time synchronization and centralized monitoring functions without adding dedicated time synchronization lines or changing the overall architecture of the existing power metering system. On the one hand, by modulating the standard time into a carrier signal and transmitting it to the A, B, and C phase power lines, the construction costs associated with adding new communication links are avoided. On the other hand, by aggregating the time differences of terminals and uploading them uniformly through the master station, frequent interactions between terminals and servers are reduced, communication bandwidth usage and system operating load are lowered, and the stability and scalability of the solution are improved under large-scale distribution area deployment conditions. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a flowchart illustrating a high-precision time synchronization method applied to an electricity metering system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the system architecture of the high-precision time synchronization method according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the timing interaction of the high-precision time synchronization method according to an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the calculation of master-slave clock time deviation in a bidirectional message time synchronization mechanism according to an embodiment of the present invention. Figure 5 This is a schematic diagram of a high-precision time synchronization device applied to an electricity metering system according to an embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0021] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0022] Example 1 like Figure 1 and Figure 2As shown, this embodiment provides a high-precision time synchronization method for electricity metering systems, applicable to time synchronization and status monitoring scenarios of electricity metering devices in power systems. The method includes steps S1 to S3. The electricity metering system includes a reference time station, a concentrator, and electricity metering devices. The concentrator houses a Central Coordinator (CCO), and the electricity metering devices are equipped with Power Line Carrier Terminal Stations (STAs).

[0023] In existing electricity metering systems, electricity meters typically connect to concentrators via High-speed Power Line Communication (HPLC). The concentrators then use a three-tiered communication architecture—master station, concentrator, and electricity meters—to complete data acquisition and control transmission. Current HPLC time synchronization mechanisms often employ the concentrator broadcasting time synchronization commands to the electricity meters at fixed intervals. However, this method is prone to accumulating delays during multi-level forwarding when the network is deeply layered, electricity meters are widely distributed within a distribution area, or communication link quality fluctuates. This causes the time synchronization accuracy of remote electricity meters to degrade from milliseconds to seconds or even greater. Furthermore, existing time synchronization processes are mostly one-way command transmissions, lacking feedback and centralized monitoring of time deviations at the terminal side. This makes it difficult to promptly grasp the synchronization status of each electricity meter within a distribution area. Moreover, point-to-point time synchronization or repeated calibration consumes significant communication bandwidth and is inefficient, failing to meet the needs of large-scale distribution areas for high-precision time synchronization and operational status monitoring.

[0024] Based on the above problems, this embodiment constructs a complete process of time reference tracing, stable transmission, two-way synchronization and centralized monitoring. Without changing the overall architecture of the existing power metering system, it realizes high-precision time synchronization of power metering devices in the transformer area and centralized monitoring of the synchronization status, thereby forming a closed-loop time synchronization and monitoring system.

[0025] like Figure 1 and Figure 3 As shown, in step S1, the concentrator interacts with the reference time station through satellite common-view technology to obtain the time difference between the concentrator's local time and the reference time station, and compensates the internal clock of the concentrator based on the time difference to output standard time.

[0026] In this embodiment, the provincial grid side is the provincial data and time service side of the power system, which is used to provide provincial-level time reference services and data aggregation services. The provincial grid side can be deployed with a reference time station and a provincial grid data server. The reference time station is used to generate and provide reference time-related data for time comparison, and the provincial grid data server is used to receive and store the synchronization status data of each terminal in the distribution area to achieve centralized monitoring.

[0027] Specifically, the concentrator first generates a local Common GNSS Generic Time Transfer Standard (CGGTTS) file based on the satellite signals it receives. This file is used to characterize the correspondence between the concentrator's local clock and satellite time. At the same time, the reference time station generates a GNSS Generic Time Transfer Standard file on its side and sends it to the concentrator via a mobile communication network. The mobile communication network can be a fourth-generation mobile communication network or a fifth-generation mobile communication network, and the Global Navigation Satellite System (GNSS) can include the BeiDou Navigation Satellite System.

[0028] After receiving the Global Navigation Satellite System (GNSS) Universal Time Transfer Standard (UTS) format file from the reference time station, the concentrator performs a difference operation between its local GNSS UTS format file and the reference time station's GNSS UTS format file to obtain the time difference between the concentrator's local time and the reference time station. The concentrator then compensates its internal clock based on this time difference and outputs the standard time after the compensation is completed.

[0029] Furthermore, the concentrator and the provincial network can also interact via mobile communication networks to request and distribute time comparison data. Specifically, the concentrator sends a time comparison data request to the provincial network, which responds by distributing a Global Navigation Satellite System (GNSS) universal time transfer standard format file from the reference time station to the concentrator. After time synchronization within the distribution area is completed, the distribution area is a collection of power metering devices within the power supply area of ​​the distribution transformer managed by the concentrator. The power line carrier master station aggregates the time deviations reported by multiple power line carrier terminal stations within the distribution area and provides this data to the concentrator. The concentrator then uploads the aggregated results to the provincial network data server via mobile communication networks, enabling the server to receive and store the aggregated results for centralized monitoring and analysis of the synchronization status of each power line carrier terminal station within the distribution area.

[0030] Using the above method, the concentrator can reproduce a time reference consistent with the base time station locally without directly connecting to an external dedicated time synchronization line, providing a unified and stable time source for subsequent time synchronization within the distribution area. This method fully utilizes the high-precision characteristics of satellite common-view technology, effectively reducing the impact of communication link instability on the accuracy of the time reference.

[0031] In step S2, the power line carrier master station deployed on the concentrator acquires the standard time and transmits the standard time to the power line carrier terminal stations deployed on the power metering devices within the distribution area via power line carrier communication.

[0032] Specifically, after acquiring the standard time output by the concentrator, the power line carrier master station analyzes and modulates the analyzed time information into a carrier signal. Subsequently, the power line carrier master station loads the carrier signal onto the A-phase, B-phase, and C-phase power lines for transmission.

[0033] Power line carrier terminal stations within the distribution area extract carrier signals from the corresponding power lines and demodulate them to obtain standard time. By reusing existing power lines as the transmission medium for time signals, standard time can be distributed within the distribution area without the need to lay additional dedicated communication lines, thereby reducing system deployment costs and improving the feasibility of time synchronization.

[0034] In step S3, the power line carrier terminal station adopts a two-way message time synchronization mechanism to determine the time deviation between the power line carrier terminal station and the power line carrier master station, and compensates the internal clock according to the time deviation to achieve time synchronization.

[0035] In this embodiment, the bidirectional message time synchronization mechanism can adopt the Precision Time Protocol (PTP).

[0036] like Figure 4 As shown, the power line carrier master station acts as the master clock, and the power line carrier terminal station acts as the slave clock. The master clock and slave clock exchange timestamps through the synchronization message sync, the follow message Follow_Up, the delay request message Delay_Req, and the delay response message Delay_Resp. In the process of message exchange, the basis for calculating the link delay and time offset is formed.

[0037] Specifically, the power line carrier master station sends a synchronization message sync to the power line carrier terminal station, and records the sending time of the synchronization message sync as t1 based on the master station's local clock.

[0038] After sending the synchronization message sync, the power line carrier master station sends a follow message Follow_Up to the power line carrier terminal station, and carries the sending time t1 in the Follow_Up message.

[0039] The power line carrier terminal station receives the synchronization message sync and records the reception time of the synchronization message sync as t2 based on the terminal's local clock. At the same time, it receives the follow message Follow_Up to obtain the transmission time t1.

[0040] Subsequently, the power line carrier terminal station sends a delay request message Delay_Req to the power line carrier master station, and records the sending time of the delay request message Delay_Req as t3 based on the terminal's local clock.

[0041] The power line carrier master station receives the delay request message Delay_Req and records the reception time of the delay request message Delay_Req as t4 based on the master station's local clock. Then, it sends a delay response message Delay_Resp to the power line carrier terminal station, and carries the reception time t4 in the delay response message Delay_Resp.

[0042] The power line carrier terminal station receives the delay response message Delay_Resp to obtain the reception time t4, and calculates the time offset Offset based on the following formula: Offset = 1 / 2 × [(t2) t1)+(t3 t4)).

[0043] Where t1 is the synchronization message transmission time recorded by the local clock of the power line carrier master station, t2 is the synchronization message reception time recorded by the local clock of the power line carrier terminal station, t3 is the delay request message transmission time recorded by the local clock of the power line carrier terminal station, and t4 is the delay request message reception time recorded by the local clock of the power line carrier master station. The power line carrier terminal station compensates its internal clock according to the time offset to ensure that its time output is consistent with that of the power line carrier master station.

[0044] By using bidirectional message exchange, the time deviation between the terminal station and the master station can be accurately calculated without pre-assuming one-way link delay, effectively improving the synchronization accuracy of terminals within the distribution area.

[0045] After step S3, the power line carrier terminal station reports its calculated time deviation to the power line carrier master station. The power line carrier master station summarizes the time deviations of multiple power line carrier terminal stations in the distribution area and provides the summary results to the concentrator.

[0046] The concentrator uploads the aggregated results to a data server via a mobile communication network. The data server receives and stores the aggregated results to monitor the synchronization status of each power line carrier terminal site within the distribution area. In this way, the server can centrally monitor the time synchronization status of each power metering device within the distribution area and provide data support for subsequent operation and maintenance, anomaly analysis, and optimization of time synchronization strategies.

[0047] Under this closed-loop mechanism, power line carrier terminal sites do not need to frequently interact directly with the server. Instead, they can uniformly aggregate and upload data through the main station and concentrator, thereby reducing communication load and improving the overall operating efficiency of the system.

[0048] Through the above steps, this embodiment completes the entire process from tracing the reference time station, generating the standard time of the concentrator, distributing the standard time within the distribution area, calculating and compensating the time deviation of the power line carrier terminal site, and centrally monitoring the synchronization status. It realizes a closed-loop system of high-precision time synchronization and dynamic monitoring, which can effectively improve the time synchronization accuracy and operational controllability of the power metering system in large-scale distribution area scenarios.

[0049] In summary, this invention achieves a high-precision, monitorable time synchronization system within the existing power metering system architecture through a closed-loop structure comprising reference time station tracing, concentrator time reproduction, power line carrier standard time distribution, terminal bidirectional message synchronization, and centralized monitoring of synchronization status. This solution avoids the problems of insufficient accuracy and imperceptible effects of traditional one-way broadcast time synchronization, and enables continuous monitoring and rapid location of synchronization status through terminal time difference feedback and centralized aggregation mechanisms. Furthermore, the solution reuses existing power line carrier communication and mobile communication network resources, eliminating the need for additional dedicated time synchronization lines. Balancing synchronization accuracy, engineering feasibility, and system scalability, it effectively improves the time consistency of power metering devices within a distribution area, providing a reliable time foundation for time-of-use metering, event analysis, and refined power grid management.

[0050] Example 2 like Figure 5 As shown, based on the same inventive concept as the above embodiments, the present invention also provides a high-precision time synchronization device for use in an electricity metering system. The high-precision time synchronization device is deployed in the electricity metering system, which includes a reference time station, a concentrator, and an electricity metering device. The high-precision time synchronization device includes: The concentrator is used to compare and interact with the reference time station through satellite common-view technology, obtain the time difference between the concentrator's local time and the reference time station, and compensate the internal clock of the concentrator based on the time difference to output standard time. The power line carrier master station is deployed on the concentrator to obtain the standard time and transmit the standard time to the power line carrier terminal stations deployed on the power metering devices in the distribution area via power line carrier communication. Power line carrier terminal stations are deployed on power metering devices. They are used to determine the time deviation between the power line carrier terminal station and the power line carrier master station using a two-way message time synchronization mechanism, and to compensate the internal clock based on the time deviation to achieve time synchronization.

[0051] In this embodiment of the invention, the power line carrier terminal station is also used to report the time deviation to the power line carrier master station; The power line carrier master station is also used to summarize the time deviations of multiple power line carrier terminal sites within the distribution area and provide the summary results to the concentrator. The concentrator is also used to upload the aggregated results to the data server via the mobile communication network, so that the data server can receive and store them to monitor the synchronization status of each power line carrier terminal site in the distribution area.

[0052] In this embodiment of the invention, the power line carrier master station is also used to send a synchronization message to the power line carrier terminal station, and record the sending time of the synchronization message as t1 based on the master station's local clock; After sending the synchronization message, the power line carrier master station is also used to send a follow-up message to the power line carrier terminal station, and carries the sending time t1 in the follow-up message; The power line carrier terminal site is also used to receive synchronization messages, record the reception time of the synchronization message as t2 based on the terminal's local clock, and receive follow-up messages to obtain the transmission time t1; The power line carrier terminal site is also used to send delay request messages to the power line carrier master station, and records the sending time of the delay request message as t3 based on the local clock of the terminal. The power line carrier master station is also used to receive delay request messages and record the reception time of the delay request message as t4 based on the master station's local clock. The power line carrier master station is also used to send delay response messages to power line carrier terminal stations, and carries the reception time t4 in the delay response messages; The power line carrier terminal station is also used to receive delay response messages to obtain the reception time t4, and to calculate the time offset based on the following formula: Offset = 1 / 2 × [(t2) t1)+(t3 t4)).

[0053] In this embodiment of the invention, the concentrator is also used to generate a local global satellite navigation system universal time transfer standard format file on the concentrator side; The reference time station is also used to generate a global satellite navigation system universal time transfer standard format file on the reference time station side, and send it to the concentrator via a mobile communication network; The concentrator is also used to receive the Global Navigation Satellite System Universal Time Transfer Standard (GNSSUP) format file from the reference time station, and to perform difference processing on the local GNSSUP format file and the GNSSUP format file from the reference time station to obtain the time difference. Based on the time difference, the internal clock is compensated and the standard time is output.

[0054] In this embodiment of the invention, the power line carrier master station is also used to modulate the standard time into a carrier signal and load the carrier signal onto the A-phase, B-phase, and C-phase power lines for transmission. Power line carrier terminal sites are also used to extract carrier signals from power lines and demodulate them to obtain standard time.

[0055] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A high-precision time synchronization method for use in an electricity metering system, characterized in that, The electricity metering system includes a reference time station, a concentrator, and an electricity metering device; the method includes: The concentrator interacts with the reference time station through satellite common-view technology to obtain the time difference between the concentrator's local time and the reference time station, and compensates the internal clock of the concentrator based on the time difference to output standard time. The power line carrier master station deployed on the concentrator obtains the standard time and transmits the standard time to the power line carrier terminal station deployed on the power metering device in the distribution area via power line carrier communication. The power line carrier terminal station uses a two-way message time synchronization mechanism to determine the time deviation between the power line carrier terminal station and the power line carrier master station, and compensates the internal clock according to the time deviation to achieve time synchronization.

2. The high-precision time synchronization method for an electricity metering system according to claim 1, characterized in that, Also includes: The power line carrier terminal station reports the time deviation to the power line carrier master station; The power line carrier master station summarizes the time deviations of multiple power line carrier terminal sites within the distribution area and provides the summary results to the concentrator. The concentrator uploads the aggregated results to the data server via a mobile communication network. The data server receives and stores the aggregated results for monitoring the synchronization status of each power line carrier terminal site within the distribution area.

3. The high-precision time synchronization method for an electricity metering system according to claim 1, characterized in that, The step of determining the time deviation between the power line carrier terminal station and the power line carrier master station includes: The power line carrier master station sends a synchronization message to the power line carrier terminal station, and the power line carrier master station records the transmission time of the synchronization message as t1 based on the master station's local clock; After sending the synchronization message, the power line carrier master station sends a follow-up message to the power line carrier terminal station, and carries the sending time t1 in the follow-up message; The power line carrier terminal station receives the synchronization message, and the power line carrier terminal station records the reception time of the synchronization message as t2 on its local clock, and receives the follow message to obtain the transmission time t1; The power line carrier terminal station sends a delay request message to the power line carrier master station, and the power line carrier terminal station records the time of transmission of the delay request message as t3 based on the terminal's local clock. The power line carrier master station receives the delay request message, and the power line carrier master station records the reception time of the delay request message as t4 based on the master station's local clock; The power line carrier master station sends a delay response message to the power line carrier terminal station and carries the receiving time t4 in the delay response message; The power line carrier terminal station receives the delay response message to obtain the reception time t4, and calculates the time offset based on the following formula: Offset=1 / 2×[(t2 t1)+(t3 t4)].

4. The high-precision time synchronization method for an electricity metering system according to claim 1, characterized in that, The steps for the concentrator to perform time comparison and interaction with the reference time station via satellite common-view technology include: The concentrator generates a local global satellite navigation system universal time transfer standard format file on the concentrator side; The reference time station generates a global satellite navigation system universal time transfer standard format file on the reference time station side and sends it to the concentrator through a mobile communication network; The concentrator receives the Global Navigation Satellite System General Time Transmission Standard Format file from the reference time station and performs a difference operation between the local Global Navigation Satellite System General Time Transmission Standard Format file and the Global Navigation Satellite System General Time Transmission Standard Format file from the reference time station to obtain the time difference. The concentrator compensates its internal clock based on the time difference and outputs a time-frequency signal as the standard time after compensation.

5. The high-precision time synchronization method for an electricity metering system according to claim 1, characterized in that, The step of transmitting the standard time to the power line carrier terminal station deployed on the power metering device within the distribution area via power line carrier communication includes: The power line carrier master station acquires the standard time and modulates the standard time into a carrier signal; The power line carrier master station loads the carrier signal onto the A-phase, B-phase, and C-phase power lines respectively for transmission; The power line carrier terminal station extracts the carrier signal from the power line and demodulates it to obtain the standard time.

6. A high-precision time synchronization device for use in an electricity metering system, characterized in that, The high-precision time synchronization device is deployed in the power metering system, which includes a reference time station, a concentrator, and a power metering device. The high-precision time synchronization device includes: The concentrator is used to perform time comparison and interaction with the reference time station through satellite common-view technology, obtain the time difference between the local time of the concentrator and the reference time station, and compensate the internal clock of the concentrator based on the time difference to output standard time. A power line carrier master station, which is deployed on the concentrator, is used to acquire the standard time and transmit the standard time to the power line carrier terminal stations deployed on the power metering device within the distribution area via power line carrier communication. A power line carrier terminal station, deployed on the power metering device, is used to determine the time deviation of the power line carrier terminal station relative to the power line carrier master station using a two-way message time synchronization mechanism, and to compensate the internal clock according to the time deviation to achieve time synchronization.

7. The high-precision time synchronization device for an electricity metering system according to claim 6, characterized in that, The power line carrier terminal station is also used to report the time deviation to the power line carrier master station; The power line carrier master station is also used to summarize the time deviations of multiple power line carrier terminal sites within the distribution area and provide the summary results to the concentrator. The concentrator is also used to upload the aggregated results to a data server via a mobile communication network, so that the data server can receive and store them for monitoring the synchronization status of each power line carrier terminal site within the distribution area.

8. The high-precision time synchronization device for an electricity metering system according to claim 6, characterized in that, The power line carrier master station is also used to send synchronization messages to power line carrier terminal stations, and record the sending time of the synchronization message as t1 based on the master station's local clock; After sending the synchronization message, the power line carrier master station is also used to send a follow-up message to the power line carrier terminal station, and carry the sending time t1 in the follow-up message; The power line carrier terminal station is also used to receive the synchronization message, record the reception time of the synchronization message as t2 based on the terminal's local clock, and receive the follow message to obtain the transmission time t1. The power line carrier terminal station is also used to send a delay request message to the power line carrier master station, and record the sending time of the delay request message as t3 based on the local clock of the terminal. The power line carrier master station is also used to receive the delay request message and record the reception time of the delay request message as t4 based on the master station's local clock. The power line carrier master station is also used to send a delay response message to the power line carrier terminal station, and to carry the receiving time t4 in the delay response message; The power line carrier terminal station is also used to receive the delay response message to obtain the reception time t4, and to calculate the time deviation Offset based on the following formula: Offset=1 / 2×[(t2 t1)+(t3 t4)].

9. The high-precision time synchronization device for an electricity metering system according to claim 6, characterized in that, The concentrator is also used to generate a local global satellite navigation system universal time transfer standard format file on the concentrator side; The reference time station is also used to generate a global satellite navigation system universal time transfer standard format file on the reference time station side, and send it to the concentrator through a mobile communication network; The concentrator is also used to receive the Global Navigation Satellite System Universal Time Transmission Standard Format file from the reference time station, and to perform difference processing on the local Global Navigation Satellite System Universal Time Transmission Standard Format file and the Global Navigation Satellite System Universal Time Transmission Standard Format file from the reference time station to obtain the time difference, and to output the standard time after compensating the internal clock based on the time difference.

10. The high-precision time synchronization device for an electricity metering system according to claim 6, characterized in that, The power line carrier master station is also used to modulate the standard time into a carrier signal and load the carrier signal onto the A-phase, B-phase, and C-phase power lines for transmission. The power line carrier terminal station is also used to extract the carrier signal from the power line and demodulate it to obtain the standard time.

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