A distribution network DTU data synchronization method and system supporting multiple synchronization algorithms

Abstract

The application provides a network distribution DTU data synchronization method supporting multiple synchronization algorithms, comprising: setting multiple synchronization algorithm calculation modules, a synchronization algorithm self-switching module and a sampling synchronization calculation module for a DTU device; the multiple synchronization algorithm calculation modules configure multiple synchronization algorithms and calculate synchronization parameters based on each synchronization algorithm, including synchronization quality Q; the synchronization algorithm self-switching module selects a synchronization algorithm with optimal synchronization quality according to the network type used for communication between each DTU device, the synchronization quality Q and the accuracy of each synchronization algorithm, and obtains the synchronization parameters corresponding to the synchronization algorithm with optimal synchronization quality; the sampling synchronization calculation module uses the synchronization parameters provided by the synchronization algorithm self-switching module and the opposite side sampling data sent by the opposite side DTU device to perform calculation, and converts the opposite side sampling data into synchronization data synchronized with the local side sampling data. The application can realize sampling synchronization of the DTU device under multiple synchronization algorithms in the scene of multiple opposite side devices interconnected.

Description

Technical Field

[0001] This invention relates to the technical field of relay protection, and more specifically, to a distribution network DTU data synchronization method and system that supports multiple synchronization algorithms. Background Technology

[0002] Distribution Terminal Units (DTUs) are crucial equipment in distribution networks, used for data acquisition and calculation of primary quantities in the power grid. Currently, the industry commonly incorporates differential protection functionality into DTUs to more accurately locate and quickly isolate fault points. The implementation of differential protection requires adjacent DTUs in the distribution network to exchange sampled data and synchronize sampled data at both ends.

[0003] Devices that typically support differential protection will set up a dedicated fiber optic network to connect the devices on both sides point-to-point. However, in actual distribution network applications, some sites do not have dedicated differential protection fiber optic channels. Therefore, when designing distribution network DTU equipment, it is necessary to consider compatibility with various communication networks such as fiber optics, cables, 4G, and 5G.

[0004] In the field of relay protection, fiber-optic-based differential protection devices generally use the ping-pong method for synchronization. The ping-pong method requires a "rigid network," meaning fixed network routing, fixed communication delay, and equal round-trip communication delay. However, 4G and 5G wireless networks, due to their large and variable communication delays, cannot use the ping-pong method. Currently, differential protection on wireless networks mostly uses a clock synchronization method based on a unified clock signal. Synchronization is achieved using an externally accessed unified clock signal, but this method relies on an external time source; if the external time signal is abnormal, the differential protection function must be blocked. Therefore, some scholars have proposed a self-synchronization method for differential protection based on the fault time. This method synchronizes sampled data based on the principle of identical fault times. However, this method is difficult to calculate the absolute fault time, resulting in generally low synchronization accuracy, and synchronization cannot be achieved when only one side operates. Currently, some scholars have also proposed a self-synchronization algorithm based on the phase of the non-fault state voltage waveform. However, this scheme cannot prepare synchronized sampled data before the fault occurs when an open-circuit line is connected to a fault. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a distribution network DTU data synchronization method and system that supports multiple synchronization algorithms. In scenarios where multiple devices are interconnected, sampling synchronization with multiple devices is achieved by setting up a set of modules for each device.

[0006] The present invention adopts the following technical solution.

[0007] A method for synchronizing data of distribution network DTUs that supports multiple synchronization algorithms includes the following steps:

[0008] Step 1: Set up multiple synchronization algorithm calculation modules, synchronization algorithm self-switching modules, and sampling synchronization calculation modules for the DTU device. The local DTU device and the remote DTU device are connected through multiple synchronization algorithm calculation modules.

[0009] Step 2: The multi-synchronization algorithm calculation module configures multiple synchronization algorithms and calculates synchronization parameters based on each algorithm. These synchronization parameters include: the synchronization benchmark t between the crystal oscillator clocks inside the local DTU device and the remote DTU device. 对侧 and t 本侧 , clock ratio on both sides M, synchronization quality Q;

[0010] Step 3: The synchronization algorithm self-switching module selects the synchronization algorithm with the best synchronization quality based on the network type, synchronization quality Q and accuracy of each synchronization algorithm used for communication between the local DTU device and the remote DTU device, and obtains the synchronization parameters corresponding to the synchronization algorithm with the best synchronization quality.

[0011] Step 4: The sampling synchronization calculation module uses the synchronization parameters provided by the synchronization algorithm self-switching module and the sampling data sent by the DTU device on the other side to perform calculations, and converts the sampling data on the other side into synchronization data that is synchronized with the sampling data on this side.

[0012] Preferably, in step 2, the synchronization algorithm further includes: an external time synchronization algorithm, a ping-pong synchronization algorithm, a phase self-synchronization algorithm, and a fault-time self-synchronization algorithm.

[0013] Preferably, in step 2, the synchronization benchmark t 对侧 t 本侧 These are the timestamps of the crystal clocks of the local DTU device and the DTU device on the opposite side at the same moment, generated based on the internal crystal clock of each DTU device, and the unit is nanoseconds.

[0014] Preferably, in step 2, calculating the clock ratio M between the two sides based on each synchronization algorithm further includes:

[0015] Based on the crystal clocks of both devices, calculate the ratio of the time measurement length within the same time period, which is the clock ratio M between the two devices.

[0016] Preferably, in step 2, the calculation of synchronization quality Q further includes: calculating the time accuracy through each synchronization algorithm, and obtaining the value of synchronization quality Q based on the time accuracy of the IRIG-B code.

[0017] Preferably, step 3 further includes:

[0018] Step 3-1: The synchronization algorithm self-switching module selects the range of available synchronization algorithms based on the type of communication network used by the DTU device.

[0019] Step 3-2: For the available synchronization algorithms, the synchronization algorithm self-switching module receives the synchronization quality Q corresponding to each synchronization algorithm obtained in step 2, and sorts them by combining the magnitude of the synchronization quality Q and the accuracy capability of the synchronization algorithm itself, and selects the synchronization algorithm with the best synchronization quality.

[0020] Preferably, in step 3-1, the communication network type used by the DTU device includes rigid networks and non-rigid networks, and the range of synchronization algorithms that can be used according to the communication network type also includes:

[0021] For the synchronization algorithm self-switching module, when the communication network used by the DTU device is a rigid network, only the external time synchronization algorithm and the ping-pong synchronization algorithm can be used.

[0022] When the communication network used by the DTU device is a non-rigid network, it can use external time synchronization algorithms, ping-pong synchronization algorithms, phase self-synchronization algorithms, and fault-time self-synchronization algorithms.

[0023] Preferably, step 3-2 further includes:

[0024] Within the range of available synchronization algorithms determined in step 3-1, the synchronization quality Q calculated by each synchronization algorithm within the range is compared first, and the synchronization algorithm with the best synchronization quality Q is selected, that is, the synchronization algorithm corresponding to the smallest synchronization quality Q is selected first.

[0025] When multiple synchronization algorithms have the same synchronization quality Q, they are sorted according to their own accuracy capability, that is, the best synchronization quality they can provide, and the synchronization algorithm that can provide better quality is selected. The best synchronization quality that each synchronization algorithm can provide is sorted as follows: external time synchronization algorithm, ping-pong synchronization algorithm, phase self-synchronization algorithm, and fault-time self-synchronization algorithm.

[0026] Preferably, step 4 further includes:

[0027] Step 4-1: The sampling synchronization calculation module receives the sampling data sent by the DTU device on the other side and uses the synchronization parameters to convert the sampling time stamp t of the sampling data on the other side into the local time stamp.

[0028] The resulting local timescale t 转 satisfy:

[0029] t 转 =t 本侧 +(tt 对侧 )*M

[0030] Step 4-2: Using the difference method, based on the sampling time of this side, the sampling data of the opposite side is resampled by difference to obtain the sampling data of the opposite side that is synchronized with the local sampling data, i.e., the synchronized data.

[0031] The present invention also provides a distribution network DTU data synchronization system that supports multiple synchronization algorithms, including: a multiple synchronization algorithm calculation module, a synchronization algorithm self-switching module, and a sampling synchronization calculation module;

[0032] The multi-synchronization algorithm calculation module can calculate synchronization parameters for synchronizing sampled data under different synchronization algorithms. These synchronization parameters include: the synchronization benchmark t for the local and remote sides. 对侧 t 本侧 , clock ratio on both sides M, synchronization quality Q;

[0033] The synchronization algorithm self-switching module is used to automatically select the synchronization algorithm with the best current synchronization quality based on the synchronization quality Q calculated by each synchronization algorithm, and obtain the synchronization parameters corresponding to the selected synchronization algorithm through the multiple synchronization algorithm calculation module, and provide them to the sampling synchronization calculation module.

[0034] The sampling synchronization calculation module converts the sampled data based on the synchronization parameters provided by the synchronization algorithm self-switching module. This includes converting the sampling time stamp of the sampled data from the other side to the local time stamp, and using the difference method to resample the sampled data from the other side based on the sampling time of the local side, so as to obtain the sampled data from the other side that is synchronized with the local sampled data.

[0035] The beneficial effects of the present invention are that, compared with the prior art, the present invention can synchronize the sampling data of adjacent DTU devices when using different communication networks, so that the DTU devices can realize differential protection function in various complex usage scenarios of the distribution network, and can improve the synchronization accuracy. It can also achieve synchronization when one side operates, and can prepare the synchronization of sampling data before the fault occurs when the distribution network line encounters an open-circuit line or a fault. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating the distribution network DTU data synchronization method that supports multiple synchronization algorithms in this invention.

[0037] Figure 2 This is a schematic diagram illustrating the self-switching of synchronization quality Q and various synchronization algorithms in this invention;

[0038] Figure 3 This is a schematic diagram of the structure of the distribution network DTU data synchronization system that supports multiple synchronization algorithms in this invention. Detailed Implementation

[0039] The present application will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and should not be construed as limiting the scope of protection of the present application.

[0040] like Figure 1 As shown, this invention proposes a method for synchronizing distribution network DTU data that supports multiple synchronization algorithms. The method includes the following steps:

[0041] Step 1: Set up multiple synchronization algorithm calculation modules, synchronization algorithm self-switching modules, and sampling synchronization calculation modules for the DTU device. The local DTU device and the remote DTU device are connected through multiple synchronization algorithm calculation modules.

[0042] Each DTU device is equipped with multiple synchronization algorithm calculation modules, a synchronization algorithm self-switching module, and a sampling synchronization calculation module, and the multiple synchronization algorithm calculation modules of this DTU device and the multiple synchronization algorithm calculation modules of the opposite DTU device are interconnected.

[0043] Furthermore, in scenarios where multiple devices are interconnected, each device is equipped with a set of multiple synchronization algorithm calculation modules, a synchronization algorithm self-switching module, and a sampling synchronization calculation module. In this way, multiple devices can be interconnected through multiple synchronization algorithm calculation modules and achieve sampling synchronization through subsequent calculations.

[0044] Step 2: The multi-synchronization algorithm calculation module configures multiple synchronization algorithms and calculates the synchronization parameters for each algorithm. These synchronization parameters include the synchronization benchmark t between the crystal oscillator clocks inside the local DTU and the remote DTU. 对侧 and t 本侧 , clock ratio on both sides M, synchronization quality Q;

[0045] The synchronization algorithms include: external time synchronization algorithm, ping-pong synchronization algorithm, phase self-synchronization algorithm, and fault-time self-synchronization algorithm.

[0046] Specifically, the external time synchronization algorithm is based on a unified external clock. It converts the internal crystal clock of each DTU device to the unified external clock. The time conversion is achieved by converting the internal crystal clock of the other DTU device to the unified external clock and then to the internal crystal clock of the local DTU device.

[0047] The ping-pong synchronization algorithm measures the latency of the current communication network by sending ping-pong messages to the other end and receiving a reply, thereby enabling the conversion of time scales between the two sides.

[0048] The phase self-synchronization algorithm is based on the fact that two devices in the distribution network are close to each other. Therefore, by comparing the phase of the same channel on both sides during non-fault times, the conversion parameters of the internal clocks of the two devices can be calculated, thus providing synchronization services during fault times.

[0049] The fault-time self-synchronization algorithm aligns the internal clocks of both devices at the moment the fault occurs and calculates the conversion method of the internal clocks of both devices.

[0050] Based on various synchronization algorithms, the synchronization benchmark t of the crystal oscillator clocks inside the local DTU device and the remote DTU device is calculated. 对侧 t 本侧 Synchronous benchmark t 对侧 t 本侧 These are the timestamps of the crystal clocks of the local DTU device and the DTU device on the opposite side at the same moment, generated based on the internal crystal clocks of each DTU device, and the units are uniformly converted to nanoseconds.

[0051] The calculation of the clock ratio M between the two sides based on the synchronization algorithms also includes: calculating the ratio of the time measurement length within the same time period based on the crystal oscillator clocks of the two devices, which is the clock ratio M between the two sides.

[0052] The calculation of synchronization quality Q also includes: calculating the time accuracy through various synchronization algorithms, and obtaining the value of synchronization quality Q based on the time accuracy. The data format of synchronization quality Q in this invention is as follows:

[0053] Adjustments were made based on the time synchronization quality definition of IRIG-B code.

[0054] Since IRIG-B codes are mostly used as external time sources in the field of relay protection, the definition of synchronization quality Q in this invention is designed based on the time quality definition of IRIG-B codes:

[0055] Differential alarm protection typically requires that the phase deviation not exceed 3°. Based on the 50Hz frequency of my country's power grid, 3° is approximately 166.66μs. Therefore, when the synchronization quality Q equals 7, the original 1ms accuracy definition of the IRIG-B code is changed to a value of 150μs, which is close to the 3° phase difference, in order to ensure the phase requirement required by the differential protection, and the quality after quality 9 is omitted.

[0056] Preferably, since the phase deviation corresponding to 1μs is approximately 0.018°, its impact on differential protection is negligible. Therefore, the definitions of these three qualities when Q=1, 2, and 3 can be omitted.

[0057] Furthermore, the corresponding synchronization quality Q is obtained based on the time accuracy of the IRIG-B code. The correspondence between the time accuracy of the IRIG-B code and the synchronization quality Q is as follows:

[0058] If the star lock is normal and the synchronization is without deviation, then Q = 0;

[0059] If the time accuracy is better than 1μs, that is, the error value is less than 1μs, then Q = 4;

[0060] If the time accuracy is better than 10μs, that is, the error value is greater than 1μs and less than 10μs, Q = 5;

[0061] If the time accuracy is better than 100μs, that is, the error value is greater than 10μs and less than 100μs, then Q = 6;

[0062] If the time accuracy is better than 150μs, that is, the error value is greater than 100μs and less than 150μs, then Q = 7;

[0063] If the time accuracy is better than 10ms, that is, the error value is greater than 150μs and less than 10ms, then Q = 8;

[0064] If the synchronized data is unavailable, then Q = 15.

[0065] Preferably, for external time synchronization, the synchronization quality Q in this invention is defined based on the time quality of IRIG-B code time synchronization. Therefore, when the synchronization quality is based on external time synchronization, it can be calculated by the external clock source and given according to the IRIG-B code standard protocol and sent to the multiple synchronization algorithm calculation module of the DTU device. That is, for external time synchronization, there is no need for the multiple synchronization algorithm calculation module of the DTU device to perform error calculation, and the synchronization quality Q value given by the external clock source can be used directly.

[0066] The synchronization parameters corresponding to each synchronization algorithm can be obtained through calculations by various synchronization algorithm calculation modules.

[0067] Step 3: The synchronization algorithm self-switching module selects the synchronization algorithm with the best synchronization quality based on the communication network type used by the DTU device, the synchronization quality Q, and the accuracy of each synchronization algorithm, and obtains the synchronization parameters corresponding to the synchronization algorithm with the best synchronization quality.

[0068] Step 3 also includes:

[0069] Step 3-1: The synchronization algorithm self-switching module selects the range of available synchronization algorithms based on the type of communication network used by the DTU device.

[0070] Specifically, based on the actual network environment in which the DTU is used, the communication network type used by the DTU device can be divided into two types: rigid network and non-rigid network.

[0071] A rigid network must satisfy the conditions of fixed network routing, fixed communication delay, and equal round-trip communication delay. If these conditions are not met, it indicates that the communication network type used is a non-rigid network.

[0072] In general, direct fiber optic or network cable connections can be considered rigid networks. If fiber optic or network cables are used to form a network through various routing devices, it is necessary to determine whether the current network is a rigid network based on the actual network settings. However, wireless networks such as 4G and 5G generally have more complex routing and larger communication latency jitter, so they can be considered "non-rigid networks".

[0073] For the synchronization algorithm self-switching module, when the communication network used by the DTU device is a rigid network, only the external time synchronization algorithm and the ping-pong synchronization algorithm can be used.

[0074] When the communication network used by the DTU device is a non-rigid network, it can use external time synchronization algorithms, ping-pong synchronization algorithms, phase self-synchronization algorithms, and fault-time self-synchronization algorithms.

[0075] Step 3-2: For the available synchronization algorithms, the synchronization algorithm self-switching module receives the synchronization quality Q corresponding to each synchronization algorithm obtained in step 2, and sorts them by combining the magnitude of the synchronization quality Q and the accuracy capability of the synchronization algorithm itself, and selects the synchronization algorithm with the best synchronization quality.

[0076] Specifically, within the range of available synchronization algorithms determined in step 3-1, the synchronization quality Q calculated by each synchronization algorithm within the range is compared first, and the synchronization algorithm with the best synchronization quality Q is selected, that is, the synchronization algorithm corresponding to the smallest synchronization quality Q is selected first.

[0077] When multiple synchronization algorithms have the same synchronization quality Q, they are ranked according to their own accuracy capability, that is, the best synchronization quality that each synchronization algorithm can provide. The synchronization algorithm that can provide better quality is selected first. The best synchronization quality that each synchronization algorithm can provide is ranked as follows: external time synchronization algorithm, ping-pong synchronization algorithm, phase self-synchronization algorithm, and fault-time self-synchronization algorithm.

[0078] Furthermore, the range of synchronization quality Q that each synchronization algorithm can provide is as follows: Figure 3 As shown:

[0079] When the communication network used by the DTU device is a rigid network and the ping-pong synchronization algorithm is used, the synchronization quality Q ranges from 4, 5, to 6.

[0080] When the communication network used by the DTU device is a rigid network and an external time synchronization algorithm is used, the synchronization quality Q ranges from 0, 4, 5, to 6.

[0081] When the communication network used by the DTU device is not a rigid network and an external time synchronization algorithm is used, the synchronization quality Q ranges from 0, 4, 5, to 6.

[0082] When the communication network used by the DTU device is not a rigid network and the ping-pong synchronization algorithm is used, the synchronization quality Q ranges from 6, 7, to 8.

[0083] When the communication network used by the DTU device is not a rigid network and a phase self-synchronization algorithm is used, the synchronization quality Q ranges from 5, 6, to 7.

[0084] When the communication network used by the DTU device is not a rigid network and a fault-time self-synchronization algorithm is used, the synchronization quality Q ranges from 6 to 7.

[0085] Furthermore, for external time synchronization algorithms, their synchronization quality is the same as that of external time synchronization accuracy. Therefore, the time quality provided by the external time synchronization source can be used directly. Under normal star locking conditions, it should be filled with 0. If the external time synchronization source enters self-keeping mode, the synchronization quality Q will decrease continuously with time. Then, if the synchronization quality Q exceeds 6 (error value is more than 100μs), it should be set to 15 (invalid).

[0086] For the ping-pong synchronization algorithm, fill in the required precision according to the algorithm's specifications. In rigid networks, only use a quality of 4-6. In non-rigid networks, since ping-pong synchronization is essentially unusable, the synchronization quality Q should only be 6-8. Setting Q to 15 (invalid) is not recommended if it exceeds 8. Actual measurements of 4G and 5G wireless networks, due to their large latency jitter, show a stable value of 8; therefore, the ping-pong synchronization algorithm cannot be directly used for synchronization in wireless networks.

[0087] For the phase self-synchronization algorithm, fill in the accuracy provided in the synchronization algorithm. It is only used for "non-rigid networks". The usable quality range is 5-7. Anything exceeding 15 will be invalid.

[0088] For the fault-time self-synchronization algorithm, fill in the accuracy provided in the synchronization algorithm. Since it is difficult to accurately calculate the fault time, the general error range is the current sampling interval. When sampling at 8000Hz, the sampling interval is 125μs, corresponding to a quality of 7. When calculating the fault time more accurately, you can fill in 6. If synchronization fails, set it to 15 (invalid).

[0089] Therefore, when the synchronization quality Q is the same, the preferred order of the synchronization algorithms is: external time synchronization algorithm, ping-pong synchronization algorithm, phase self-synchronization algorithm, and fault-time self-synchronization algorithm.

[0090] Based on the above synchronization algorithm selection method, if the external time source is synchronized normally, the synchronization quality Q provided by the multiple synchronization algorithm calculation module is 0, and the synchronization algorithm with the best synchronization quality is the external time synchronization algorithm. If the external time source is not synchronized normally, the synchronization algorithm with the best synchronization quality is selected and used according to the above synchronization algorithm selection steps.

[0091] Step 4: The sampling synchronization calculation module uses the synchronization parameters provided by the synchronization algorithm self-switching module and the sampling data sent by the DTU device on the other side to perform calculations, and converts the sampling data on the other side into synchronization data that is synchronized with the sampling data on this side.

[0092] Specifically, obtaining contralateral sampling data synchronized with the local sampling data also includes:

[0093] Step 4-1: The sampling synchronization calculation module receives the sampling data sent by the DTU device on the other side and uses the synchronization parameters to convert the sampling time stamp t of the sampling data on the other side into the local time stamp.

[0094] The resulting local timescale t 转 satisfy:

[0095] t 转 =t 本侧 +(tt 对侧 )*M

[0096] Step 4-2: Using the difference method, based on the sampling time of this side, the sampling data of the opposite side is resampled by difference to obtain the sampling data of the opposite side that is synchronized with the local sampling data, i.e., the synchronized data.

[0097] like Figure 3 As shown, the present invention also provides a distribution network DTU data synchronization system that supports multiple synchronization algorithms. The above-mentioned distribution network DTU data synchronization method that supports multiple synchronization algorithms can be implemented based on the system. The system includes a multiple synchronization algorithm calculation module 1, a synchronization algorithm self-switching module 2, and a sampling synchronization calculation module 3, and the above modules are set on each DTU device.

[0098] Among them, the multi-synchronization algorithm calculation module 1 can calculate the synchronization parameters used to synchronize the sampled data under different synchronization algorithm principles. The synchronization parameters include: the synchronization benchmark t on the local side and the opposite side. 对侧 t 本侧 , clock ratio on both sides M, synchronization quality Q;

[0099] The synchronization algorithm self-switching module 2 is used to automatically select the synchronization algorithm with the current synchronization quality based on the synchronization quality Q calculated by each synchronization algorithm, and obtain the synchronization parameters corresponding to the selected synchronization algorithm through the multiple synchronization algorithm calculation module 1, and provide them to the sampling synchronization calculation module 3.

[0100] The sampling synchronization calculation module 3 of the local DTU device converts the received sampled data from the other side based on the synchronization parameters provided by the self-switching module 2 of the local DTU device's synchronization algorithm. This includes converting the sampling time stamp of the other side's sampled data into the local time stamp, and using the difference method to resample the difference of the other side's sampled data based on the sampling time of the local side, so as to obtain the other side's sampled data that is synchronized with the local sampled data.

[0101] The beneficial effects of this invention are that, compared with the prior art, it can synchronize the sampling data of adjacent DTU devices when using different communication networks, enabling DTU devices to achieve differential protection functions in various complex usage scenarios of power distribution networks, and improving synchronization accuracy.

[0102] The applicant of this invention has provided a detailed description of the embodiments of the invention in conjunction with the accompanying drawings. However, those skilled in the art should understand that the above embodiments are merely preferred embodiments of the invention. The detailed description is only intended to help readers better understand the spirit of the invention and is not intended to limit the scope of protection of the invention. On the contrary, any improvements or modifications made based on the inventive spirit of the invention should fall within the scope of protection of the invention.

Claims

1. A method for synchronizing data of distribution network DTUs supporting multiple synchronization algorithms, characterized in that, Includes the following steps: Step 1: Set up multiple synchronization algorithm calculation modules, synchronization algorithm self-switching modules, and sampling synchronization calculation modules for the DTU device. The local DTU device and the remote DTU device are connected through multiple synchronization algorithm calculation modules. Step 2: The multi-synchronization algorithm calculation module configures multiple synchronization algorithms and calculates synchronization parameters based on each algorithm. These synchronization parameters include: the synchronization benchmark t between the crystal oscillator clocks inside the local DTU device and the remote DTU device. 对侧 and t 本侧 , clock ratio on both sides M, synchronization quality Q; Synchronous benchmark t 对侧 t 本侧 These are the timestamps of the crystal clocks of the local DTU device and the DTU device on the opposite side at the same moment; Step 3: The synchronization algorithm self-switching module selects the synchronization algorithm with the best synchronization quality based on the network type, synchronization quality Q and accuracy of each synchronization algorithm used for communication between the local DTU device and the remote DTU device, and obtains the synchronization parameters corresponding to the synchronization algorithm with the best synchronization quality. Step 4: The sampling synchronization calculation module uses the synchronization parameters provided by the synchronization algorithm self-switching module and the sampling data sent by the DTU device on the other side to perform calculations, and converts the sampling data on the other side into synchronization data that is synchronized with the sampling data on this side.

2. The distribution network DTU data synchronization method supporting multiple synchronization algorithms according to claim 1, characterized in that, In step 2, the synchronization algorithm also includes: external time synchronization algorithm, ping-pong synchronization algorithm, phase self-synchronization algorithm and fault time self-synchronization algorithm.

3. The distribution network DTU data synchronization method supporting multiple synchronization algorithms according to claim 1, characterized in that, In step 2, the synchronization benchmark t 对侧 t 本侧 The clock is generated based on the internal crystal oscillator clock of each DTU device, with the unit being nanoseconds.

4. The distribution network DTU data synchronization method supporting multiple synchronization algorithms according to claim 1, characterized in that, Step 2, calculating the clock ratio M between the two sides based on each synchronization algorithm, also includes: Based on the crystal clocks of both devices, calculate the ratio of the time measurement length within the same time period, which is the clock ratio M between the two devices.

5. The distribution network DTU data synchronization method supporting multiple synchronization algorithms according to claim 1, characterized in that, In step 2, the calculation of synchronization quality Q also includes: calculating the time accuracy through each synchronization algorithm, and obtaining the value of synchronization quality Q based on the time accuracy of the IRIG-B code.

6. The distribution network DTU data synchronization method supporting multiple synchronization algorithms according to claim 1, characterized in that, Step 3 also includes: Step 3-1: The synchronization algorithm self-switching module selects the range of available synchronization algorithms based on the type of communication network used by the DTU device. Step 3-2: For the available synchronization algorithms, the synchronization algorithm self-switching module receives the synchronization quality Q corresponding to each synchronization algorithm obtained in step 2, and sorts them by combining the magnitude of the synchronization quality Q and the accuracy capability of the synchronization algorithm itself, and selects the synchronization algorithm with the best synchronization quality.

7. The distribution network DTU data synchronization method supporting multiple synchronization algorithms according to claim 6, characterized in that, In step 3-1, the communication network type used by the DTU device includes rigid networks and non-rigid networks. The range of synchronization algorithms that can be used depending on the communication network type also includes: For the synchronization algorithm self-switching module, when the communication network used by the DTU device is a rigid network, only the external time synchronization algorithm and the ping-pong synchronization algorithm can be used. When the communication network used by the DTU device is a non-rigid network, it can use external time synchronization algorithms, ping-pong synchronization algorithms, phase self-synchronization algorithms, and fault-time self-synchronization algorithms.

8. The distribution network DTU data synchronization method supporting multiple synchronization algorithms according to claim 6, characterized in that, Step 3-2 further includes: Within the range of available synchronization algorithms determined in step 3-1, the synchronization quality Q calculated by each synchronization algorithm within the range is compared first, and the synchronization algorithm with the best synchronization quality Q is selected, that is, the synchronization algorithm corresponding to the smallest synchronization quality Q is selected first. When multiple synchronization algorithms have the same synchronization quality Q, they are sorted according to their own accuracy capability, that is, the best synchronization quality they can provide, and the synchronization algorithm that can provide better quality is selected. The best synchronization quality that each synchronization algorithm can provide is sorted as follows: external time synchronization algorithm, ping-pong synchronization algorithm, phase self-synchronization algorithm, and fault-time self-synchronization algorithm.

9. The distribution network DTU data synchronization method supporting multiple synchronization algorithms according to claim 1, characterized in that, Step 4 also includes: Step 4-1: The sampling synchronization calculation module receives the sampling data sent by the DTU device on the other side and uses the synchronization parameters to convert the sampling time stamp t of the sampling data on the other side into the local time stamp. The resulting local timescale t 转 satisfy: t 转 =t 本侧 +(t-t 对侧 )*M Step 4-2: Using the difference method, based on the sampling time of this side, the sampling data of the opposite side is resampled by difference to obtain the sampling data of the opposite side that is synchronized with the local sampling data, i.e., the synchronized data.

10. A distribution network DTU data synchronization system supporting multiple synchronization algorithms, utilizing the distribution network DTU data synchronization method supporting multiple synchronization algorithms as described in any one of claims 1-9, characterized in that, include: Multiple synchronization algorithm calculation module (1), synchronization algorithm self-switching module (2), and sampling synchronization calculation module (3); The multi-synchronization algorithm calculation module (1) is capable of calculating synchronization parameters for synchronizing sampled data under different synchronization algorithms. The synchronization parameters include: the synchronization benchmark t on the local side and the opposite side. 对侧 t 本侧 , clock ratio on both sides M, synchronization quality Q; The synchronization algorithm self-switching module (2) is used to automatically select the synchronization algorithm with the best current synchronization quality according to the synchronization quality Q calculated by each synchronization algorithm, and obtain the synchronization parameters corresponding to the selected synchronization algorithm through the multiple synchronization algorithm calculation module (1), and provide them to the sampling synchronization calculation module (3). The sampling synchronization calculation module (3) converts the sampling data based on the synchronization parameters provided by the synchronization algorithm self-switching module (2), including converting the sampling time stamp of the sampling data on the other side into the local time stamp, and using the difference method to resample the sampling data on the other side based on the sampling time of the local side, so as to obtain the sampling data on the other side that is synchronized with the local sampling data.

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