A distribution network differential protection method, system and distribution terminal

Abstract

The present invention discloses a distribution network differential protection method, system and distribution terminal in the field of distribution network technology. The method is executed by the distribution terminal, including: obtaining the reference time forwarded by the customer terminal device; exchanging data with the adjacent distribution terminal through the customer terminal device through the 5G deterministic network to collect complete information required for differential protection calculation; generating a data message by combining the reference time and the collected information required for differential protection calculation; transmitting the data message to the distribution management system through the 5G deterministic network, so that the distribution management system can perform differential protection calculation according to the data message; wherein the adjacent distribution terminal refers to a distribution terminal located on the same distribution line as the input end or output end of the current distribution terminal, and the information required for differential protection calculation includes at least the current sampling value flowing into and out of the distribution terminal and the time stamp information of the current sampling value. The present invention can improve the reliability of differential protection.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution networks, and in particular to a power distribution network differential protection method, system and power distribution terminal. Background Art

[0002] The distribution network differential protection uses Kirchhoff's current theorem to measure the inflow and outflow currents of the protected distribution terminal under a time synchronization mechanism. If they are equal, the differential current is zero. When a fault occurs in the distribution terminal, the current flowing into the distribution terminal and the current flowing out of the distribution terminal are no longer equal, and the differential current is greater than zero, which triggers the differential protection action, tripping the circuit breakers on each side of the distribution terminal to disconnect the power supply of the faulty equipment.

[0003] Traditional differential protection systems use optical fiber as a communication channel. Faced with huge amounts of data interaction, they cannot guarantee the synchronization of data flowing into and out of the distribution terminals, resulting in unreliable differential protection control and inability to ensure safe and reliable operation of the distribution network. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a distribution network differential protection method, system and distribution terminal, which utilize 5G deterministic networks for data transmission to improve the reliability of differential protection.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] In one aspect, the present invention provides a distribution network differential protection method, which is performed by a distribution terminal and includes:

[0007] Obtain the benchmark time forwarded by the client terminal device;

[0008] The customer terminal device exchanges data with the adjacent distribution terminal through the 5G deterministic network to collect the information required for the complete differential protection calculation;

[0009] generating a data message by combining the reference time and the collected information required for differential protection calculation;

[0010] The data message is transmitted to the distribution management system through the 5G deterministic network, so that the distribution management system can perform differential protection calculation according to the data message; wherein, the adjacent distribution terminal refers to the distribution terminal that is located on the same distribution line as the input or output end of the current distribution terminal; the information required for the differential protection calculation includes at least the current sampling values ​​flowing into and out of the distribution terminal and the time stamp information of the current sampling values.

[0011] Furthermore, the information required for differential protection calculation also includes a switch status used for differential protection control of distribution terminals.

[0012] Furthermore, the method further comprises:

[0013] The time delay for the next acquisition of information required for differential protection calculation is calculated based on the time stamp information of the current sampling value and the reference time.

[0014] Furthermore, the method for calculating the time delay for collecting the information required for the differential protection calculation next time includes:

[0015] Calculate the average time deviation of the time stamp information of the current sampling value of each distribution terminal relative to the current sampling reference time;

[0016] The average time deviation is summed with the next sampling reference time to obtain the time delay for collecting the information required for differential protection calculation next time.

[0017] Furthermore, the format of the data message is as follows:

[0018] First DTU_m DTU_n DTU_k Time_0 CRC

[0019] Among them, DTU_m, DTU_n, and DTU_k are all information required for differential protection calculation collected from adjacent distribution terminals through data exchange, Time_0 is the reference time, and CRC is the check bit.

[0020] In another aspect, the present invention provides a power distribution terminal, comprising:

[0021] Time acquisition module: used to obtain the reference time forwarded by the client terminal device;

[0022] Acquisition module: used to exchange data with adjacent distribution terminals via the customer terminal device through the 5G deterministic network to collect the complete information required for differential protection calculation;

[0023] Message generation module: used to generate a data message by combining the reference time and the information required for the differential protection calculation;

[0024] Transmission module: used to transmit the data message to the power distribution management system through the 5G deterministic network, so that the power distribution management system can perform differential protection calculation according to the data message;

[0025] Among them, the adjacent distribution terminal refers to a distribution terminal located on the same distribution line as the input or output of the current distribution terminal; the information required for the differential protection calculation includes at least the current sampling values ​​flowing into and out of the distribution terminal and the time stamp information of the current sampling values.

[0026] Furthermore, the power distribution terminal also includes:

[0027] Calculation module: used to calculate the time delay for the next acquisition of information required for differential protection calculation based on the time stamp information of the current sampling value and the reference time.

[0028] Furthermore, the calculation module includes:

[0029] The first calculation submodule is used to calculate the average time deviation of the time stamp information of the current sampling value of each distribution terminal relative to the current sampling reference time;

[0030] The second calculation submodule is used to perform a sum operation on the average time deviation and the next sampling reference time to obtain the time delay for collecting the information required for the differential protection calculation next time.

[0031] In another aspect, the present invention further provides a distribution network differential protection system, comprising:

[0032] Customer terminal equipment: used to forward the reference time to the distribution terminal and realize data exchange between the current distribution terminal and the adjacent distribution terminal through the 5G deterministic network;

[0033] Distribution terminal: used for collecting complete information required for differential protection calculation through data exchange, and generating a data message by combining the reference time and the collected information required for differential protection calculation;

[0034] Distribution management system: used to receive data messages generated by distribution terminals through 5G deterministic networks, and perform differential protection calculations based on the data messages;

[0035] Among them, the adjacent distribution terminal refers to a distribution terminal located on the same distribution line as the input or output of the current distribution terminal; the information required for the differential protection calculation includes at least the current sampling values ​​flowing into and out of the distribution terminal and the time stamp information of the current sampling values.

[0036] Furthermore, the distribution network differential protection system also includes:

[0037] Timing server: used to periodically send broadcast frames with reference time through the 5G deterministic network;

[0038] The client terminal device is also used to obtain the broadcast frame through the 5G deterministic network and extract the reference time from the broadcast frame;

[0039] The power distribution terminal is also used to calculate the time delay for the next collection of information required for differential protection calculation according to the time stamp information of the current sampling value and the reference time.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The customer terminal equipment exchanges data with the adjacent distribution terminal through the low-latency, highly reliable 5G deterministic network to collect the information required for the complete differential protection calculation, ensuring the time synchronization of the collected information, thereby improving the reliability of the differential protection action;

[0042] The time delay for the next collection of information required for differential protection calculation is calculated based on the reference time and the time stamp information of the currently collected data. The deviation of the information collection time of each distribution terminal relative to the reference time is taken into account, so that the next sampling time of each distribution terminal is accurately aligned, and the time synchronization of the information collected by each distribution terminal is further improved, making the differential protection control more accurate and reliable, which helps to ensure the safe and reliable operation of the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention provides a structure principle block diagram of a distribution network differential protection system. DETAILED DESCRIPTION

[0044] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0045] Embodiment 1:

[0046] The embodiment of the present invention provides a distribution network differential protection method, which can be Figure 1 The distribution terminal (abbreviated as DTU in the figure) in the distribution network differential protection system shown in the figure is executed. Each distribution terminal is equipped with a customer terminal device (abbreviated as CPE in the figure) connected to it, and each distribution terminal is connected to the 5G deterministic network through its own customer terminal device. The specific steps include:

[0047] Step 1: Obtain the reference time forwarded by the customer terminal device, and exchange data with the adjacent distribution terminal through the 5G deterministic network via the customer terminal device to collect the complete information required for differential protection calculation;

[0048] Step 2: Generate a data message by combining the reference time and the collected information required for differential protection calculation;

[0049] Step 3: Transmitting the data message to the power distribution management system through the 5G deterministic network, so that the power distribution management system can perform differential protection calculation according to the data message;

[0050] The information required for the differential protection calculation includes at least the current sampling values ​​flowing into and out of the distribution terminal and the time stamp information of the current sampling values. It should be noted that there can be multiple distribution terminals. Figure 1 Only three distribution terminals are shown for illustration purposes. Figure 1 The input or output of the three distribution terminals are located on the same distribution line and are adjacent distribution terminals. The current distribution terminal can realize differential protection control by collecting the current flowing into and out of the current distribution terminal from the adjacent distribution terminal. The distribution management system is part of the distribution master station and can realize differential protection calculation and differential protection instruction generation through existing computer programs.

[0051] The differential protection of the distribution network uses Kirchhoff's current theorem to measure the inflow current and outflow current of the protected distribution terminal under the time synchronization mechanism: if they are equal, the differential current is zero; if they are not equal, differential protection control needs to be performed. Therefore, the information required for the differential protection calculation described in the embodiment of the present invention includes at least the current sampling values ​​flowing into and out of the distribution terminal, and may also include the switch state used for the differential protection control of the distribution terminal.

[0052] The embodiment of the present invention adopts 5G deterministic network to replace the traditional fiber channel, which can build a horizontal network at both ends or multiple ends of the distribution network and a vertical network from the distribution terminal to the distribution master station. The 5G deterministic network has the advantages of low latency and high reliability, and can realize deterministic network communication, especially in the uRLLC scenario, which can achieve the goal of 0.5ms uplink and downlink delay, and the reliability of transmitting 32-byte packets within 1ms of user plane delay is 99.999%. Applying the 5G deterministic network to the data communication of differential protection of the distribution network can realize the real-time processing and fault isolation of differential protection control of the distribution network.

[0053] Embodiment 2:

[0054] The embodiment of the present invention provides a distribution network differential protection method, which is different from the first embodiment in that the distribution terminal also needs to calculate the delay of the next acquisition of information required for differential protection calculation to achieve accurate alignment of the sampling time of each distribution terminal, specifically including:

[0055] The time stamp information of the current sampling value is extracted, and the time delay for the next acquisition of information required for differential protection calculation is calculated based on the time stamp information and the reference time.

[0056] The reference time can be generated by a timing server connected to the 5G deterministic network. The customer terminal device can obtain the reference time through the 5G deterministic network and forward it to the power distribution terminal.

[0057] The method for calculating the time delay for the next acquisition of information required for differential protection calculation according to the time stamp information and the reference time includes:

[0058] Step a: Calculate the average time deviation of the time stamp information of the current sampling value of each distribution terminal relative to the current sampling reference time;

[0059] by Figure 1 Take the three distribution terminals shown in the figure as an example, assuming that the reference time sent by the synchronization server is T0 (i) , distribution terminal DTU m 、DTU n 、DTU k The time stamp information of the current sampling values ​​collected this time is T m (i) 、T n (i) 、T k (i) , then the average time deviation

[0060] Step b: The average time deviation is summed with the next sampling reference time to obtain the time delay for collecting the information required for the differential protection calculation next time. The calculation formula can be expressed as: Δ = T0 (i+1) +Δ i+1 , where Δ is the time delay for collecting the information required for differential protection calculation next time; It is the reference time for the next sampling received by the power distribution terminal.

[0061] It should be noted that the 5G deterministic network creates slices based on the distribution network differential protection slice template and starts data message transmission; if the delay (i.e. Δ) exceeds 10ms, it indicates that the existing slice function is aging, and the slice needs to be updated according to the differential control delay requirements.

[0062] As an embodiment of the present invention, the format of the data message can be written in the following format:

[0063] First DTU_m DTU_n DTU_k Time_0 CRC

[0064] Among them, DTU_m, DTU_n, and DTU_k are all information required for differential protection calculation collected from adjacent distribution terminals through data exchange, Time_0 is the reference time, and CRC is the check bit.

[0065] The distribution network differential protection method provided in the embodiment of the present invention calculates the delay of the next collection of information required for differential protection calculation according to the reference time and the time stamp information of the currently collected data, takes into account the deviation of the information collection time of each distribution terminal relative to the reference time, so that the next sampling time of each distribution terminal is accurately aligned, and further improves the time synchronization of the information collected by each distribution terminal, so that the differential protection control is more accurate and reliable, which helps to ensure the safe and reliable operation of the distribution network.

[0066] Embodiment three:

[0067] An embodiment of the present invention provides a power distribution terminal, which can be used to implement the method described in Embodiment 1 or Embodiment 2, specifically including:

[0068] Time acquisition module: used to obtain the reference time forwarded by the client terminal device;

[0069] Acquisition module: used to exchange data with adjacent distribution terminals via the customer terminal device through the 5G deterministic network to collect the complete information required for differential protection calculation;

[0070] Message generation module: used to generate data message by combining the information required for differential protection calculation and reference time;

[0071] Transmission module: used to transmit the data message to the power distribution management system through the 5G deterministic network, so that the power distribution management system can perform differential protection calculation according to the data message;

[0072] Among them, the adjacent distribution terminal refers to a distribution terminal located on the same distribution line as the input or output of the current distribution terminal; the information required for the differential protection calculation includes at least the current sampling values ​​flowing into and out of the distribution terminal and the time stamp information of the current sampling values.

[0073] The distribution terminal provided in the embodiment of the present invention adopts a 5G deterministic network instead of a traditional fiber optic channel to communicate with adjacent distribution terminals and a distribution management system, thereby realizing real-time processing and fault isolation of differential protection control of the distribution network.

[0074] To further ensure synchronization of sampling times of the power distribution terminals, the power distribution terminal provided in the embodiment of the present invention further includes:

[0075] Calculation module: used to calculate the time delay for the next acquisition of information required for differential protection calculation based on the time stamp information of the current sampling value and the reference time.

[0076] Specifically, the calculation module includes:

[0077] The first calculation submodule is used to calculate the average time deviation of the time stamp information of the current sampling value of each distribution terminal relative to the current sampling reference time;

[0078] The second calculation submodule is used to perform a sum operation on the average time deviation and the next sampling reference time to obtain the time delay for collecting the information required for the differential protection calculation next time.

[0079] The specific method for calculating the time delay for the next acquisition of information required for differential protection calculation may refer to the relevant contents recorded in the second embodiment.

[0080] Those skilled in the art should understand that the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0081] Embodiment 4:

[0082] like Figure 1 FIG. 1 is a block diagram showing a structure principle of a distribution network differential protection system provided by an embodiment of the present invention, including:

[0083] Customer terminal equipment: used to forward the reference time to the distribution terminal and realize data exchange between the current distribution terminal and the adjacent distribution terminal through the 5G deterministic network;

[0084] Distribution terminal: used for collecting complete information required for differential protection calculation through data exchange, and generating a data message by combining the reference time and the collected information required for differential protection calculation;

[0085] Distribution management system: used to receive data messages generated by distribution terminals through 5G deterministic networks, and perform differential protection calculations based on the data messages;

[0086] The information required for the differential protection calculation includes at least the current sampling values ​​flowing into and out of the power distribution terminal and the time stamp information of the current sampling values.

[0087] It should be noted that: there can be multiple power distribution terminals. Figure 1 Only three distribution terminals are shown for illustration purposes. Figure 1 The input or output of the three distribution terminals are located on the same distribution line and are adjacent distribution terminals. The distribution management system is a part of the distribution master station and can realize differential protection calculation and differential protection instruction generation through existing computer programs.

[0088] As an embodiment of the present invention, the distribution network differential protection system may further include:

[0089] Timing server: used to periodically send broadcast frames with reference time through the 5G deterministic network;

[0090] The client terminal device is also used to obtain the broadcast frame through the 5G deterministic network and extract the reference time from the broadcast frame;

[0091] The distribution terminal is also used to extract the time stamp information in the information required for differential protection calculation, and calculate the delay for the next collection of information required for differential protection calculation based on the time stamp information and the reference time. The specific calculation method can refer to the relevant content recorded in Example 2.

[0092] 5G deterministic networks can measure and predict deterministic network indicators by using the time stamp information in data packets, perform bidirectional mapping and coordination between services and networks, and use the network management system to orchestrate resources and manage slices. 5G deterministic networks can create end-to-end slices, achieve deterministic communication between nodes in the system, and perform real-time communication quality perception and monitoring to ensure communication quality.

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A distribution network differential protection method, executed by a distribution terminal, characterized in that: include: Obtain the benchmark time forwarded by the client terminal device; The customer terminal device exchanges data with the adjacent distribution terminal through the 5G deterministic network to collect the information required for the complete differential protection calculation; generating a data message by combining the reference time and the collected information required for differential protection calculation; Transmitting the data message to the power distribution management system through the 5G deterministic network, so that the power distribution management system can perform differential protection calculation according to the data message; The adjacent distribution terminal refers to a distribution terminal located on the same distribution line as the input terminal or output terminal of the current distribution terminal; the information required for the differential protection calculation includes at least the current sampling values ​​flowing into and out of the distribution terminal and the time stamp information of the current sampling values; The method further comprises: Calculate the time delay for the next acquisition of information required for differential protection calculation based on the time stamp information of the current sampling value and the reference time; The method for calculating the time delay for the next acquisition of information required for differential protection calculation includes: Calculate the average time deviation of the time stamp information of the current sampling value of each distribution terminal relative to the current sampling reference time; The average time deviation is summed with the next sampling reference time to obtain the time delay for collecting the information required for differential protection calculation next time.

2. The distribution network differential protection method according to claim 1, characterized in that: The information required for differential protection calculation also includes switch states used for differential protection control of distribution terminals.

3. The distribution network differential protection method according to claim 1, characterized in that: The format of the data message is as follows: ； Among them, DTU_m, DTU_n, and DTU_k are all information required for differential protection calculation collected from adjacent distribution terminals through data exchange, Time_0 is the reference time, and CRC is the check bit.

4. A power distribution terminal, characterized in that: include: Time acquisition module: used to obtain the reference time forwarded by the client terminal device; Acquisition module: used to exchange data with adjacent distribution terminals via the customer terminal device through the 5G deterministic network to collect the complete information required for differential protection calculation; Message generation module: used to generate a data message by combining the reference time and the information required for the differential protection calculation; Transmission module: used to transmit the data message to the power distribution management system through the 5G deterministic network, so that the power distribution management system can perform differential protection calculation according to the data message; Calculation module: used to calculate the time delay of the next acquisition of information required for differential protection calculation according to the time stamp information of the current sampling value and the reference time; The adjacent distribution terminal refers to a distribution terminal located on the same distribution line as the input terminal or output terminal of the current distribution terminal; the information required for the differential protection calculation includes at least the current sampling values ​​flowing into and out of the distribution terminal and the time stamp information of the current sampling values; The calculation module comprises: The first calculation submodule is used to calculate the average time deviation of the time stamp information of the current sampling value of each distribution terminal relative to the current sampling reference time; The second calculation submodule is used to perform a sum operation on the average time deviation and the next sampling reference time to obtain the time delay for collecting the information required for the differential protection calculation next time.

5. A distribution network differential protection system, characterized in that: include: Customer terminal equipment: used to forward the reference time to the distribution terminal and realize data exchange between the current distribution terminal and the adjacent distribution terminal through the 5G deterministic network; Distribution terminal: used for collecting complete information required for differential protection calculation through data exchange, and generating a data message by combining the reference time and the collected information required for differential protection calculation; Distribution management system: used to receive data messages generated by distribution terminals through 5G deterministic networks, and perform differential protection calculations based on the data messages; Timing server: used to periodically send broadcast frames with reference time through the 5G deterministic network; The client terminal device is also used to obtain the broadcast frame through the 5G deterministic network and extract the reference time from the broadcast frame; The power distribution terminal is also used to calculate the time delay for the next acquisition of information required for differential protection calculation according to the time stamp information of the current sampling value and the reference time, specifically including: Calculate the average time deviation of the time stamp information of the current sampling value of each distribution terminal relative to the current sampling reference time; The average time deviation is summed with the next sampling reference time to obtain the time delay for collecting the information required for differential protection calculation next time; Among them, the adjacent distribution terminal refers to a distribution terminal located on the same distribution line as the input or output of the current distribution terminal; the information required for the differential protection calculation includes at least the current sampling values ​​flowing into and out of the distribution terminal and the time stamp information of the current sampling values.

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