Power distribution network relay protection fixed value setting method and device

Abstract

The invention provides a power distribution network relay protection fixed value setting method and device. The method comprises the following steps: constructing a primary equipment topology connection relation of a power distribution network outgoing line unit; identifying the distributed new energy equipment in the outgoing line unit; searching a path from the distributed new energy equipment to an equivalent bus according to the topological connection relation; recording a primary equipment set in the path; integrating the primary equipment set and the equivalent bus to form global topological connection; calculating the short-circuit current of the power distribution network based on the global topological connection; and setting a fixed value of the relay protection device according to the short-circuit current. According to the invention, by constructing the multi-outlet-unit collaborative topology and identifying the new energy path, the calculation model is simplified, the new energy influence of the same bus is considered, and the short-circuit current calculation precision is improved, so that the efficient and accurate setting of the relay protection setting value is realized, and the stable operation of the power grid is ensured.

Description

Technical Field

[0001] This application belongs to the field of relay setting, and in particular relates to a method and device for setting relay protection settings in a distribution network. Background Technology

[0002] Currently, the global energy structure is undergoing a profound transformation. Driven by sustainable development strategies, the proportion of distributed renewable energy sources such as solar photovoltaic and wind power being integrated into distribution networks has increased significantly. This trend has not only accelerated the utilization of clean energy but also brought many new challenges to the operation and management of traditional distribution networks, especially in the setting of relay protection parameters, where traditional methods have revealed significant limitations.

[0003] Traditionally, in the setting of distribution network relay protection, distributed renewable energy sources are often simply treated as ordinary loads, ignoring their significant differences in characteristics compared to traditional loads. Distributed renewable energy sources are characterized by intermittency, randomness, and reverse power flow, which dynamically affect parameters such as voltage, current, and power flow direction in the distribution network. However, traditional setting methods fail to effectively assess and adjust these dynamic effects, leading to potential maloperation or failure to operate of relay protection settings when facing complex faults, severely impacting the safe and stable operation of the distribution network. Furthermore, existing distribution network relay protection setting calculation systems often only consider the topology model of the current outgoing unit when setting values, neglecting the changes in the overall distribution network topology after the integration of distributed renewable energy sources.

[0004] With the large-scale integration of distributed renewable energy sources, the topology of distribution networks has become more complex and dynamic. Relying solely on the topology model of a single outgoing unit for setting parameters is clearly insufficient to meet practical needs. This limitation results in insufficient sensitivity and selectivity of protection settings when facing complex faults, and may even lead to malfunctions or failures to operate, further threatening the safe operation of the distribution network.

[0005] Crucially, the integration of distributed renewable energy sources means that when a fault occurs at different locations in the distribution network, the short-circuit current from these renewable sources may exhibit amplifying, draining, or reverse effect, significantly altering the power supply mode and fault current distribution characteristics of the traditional distribution network. Traditional setting methods fail to adequately consider this change, resulting in relay protection devices being unable to accurately and quickly identify faults and take correct actions when faults occur, thus affecting the safe, reliable, and efficient operation of the distribution network.

[0006] Faced with these challenges, existing technologies still encounter problems when handling setting adjustments in distribution networks containing distributed renewable energy sources, such as excessively large computational models and difficulties in balancing computational efficiency and accuracy. How to improve computational efficiency while ensuring accuracy has become a critical issue that urgently needs to be addressed. Furthermore, as the scale of distributed renewable energy integration expands, setting adjustment methods need to possess greater adaptability and scalability to meet the integration requirements of distributed power sources of different scales. Summary of the Invention

[0007] The purpose of this application is to overcome the deficiencies in the prior art and provide a method and device for setting the relay protection settings of a distribution network.

[0008] This application provides a method for setting the relay protection settings in a distribution network, including:

[0009] Construct the primary equipment topology connection relationship of the outgoing unit of the distribution network;

[0010] Identify the distributed new energy equipment within the outgoing unit;

[0011] Based on the topological connection relationship, find the path from the distributed new energy equipment to the equivalent bus;

[0012] Record the set of primary devices in the path;

[0013] The primary equipment set and the equivalent bus are integrated to form a global topology connection;

[0014] Calculate the distribution network short-circuit current based on the global topology connection;

[0015] The relay protection device settings are determined based on the short-circuit current.

[0016] Optionally, the step of finding the path from the distributed new energy equipment to the equivalent bus based on the topological connection relationship includes:

[0017] Starting from the access node of the distributed new energy equipment and using the connection relationship of the primary equipment as the edge, the topology path is traversed through the breadth-first search algorithm until the equivalent bus is reached.

[0018] Optionally, the set of primary devices in the path is recorded, including:

[0019] A unique identifier is added to the node number of each outgoing unit to make the node number of different outgoing units globally unique.

[0020] Optionally, integrating the primary equipment set with the equivalent bus to form a global topology connection includes:

[0021] Get the topology of all devices in the current outgoing unit;

[0022] Obtain the equipment topology relationship from the average busbar in other outgoing units to the new energy path;

[0023] Using the equivalent bus as the root node, the above topological relationships are merged into a global topological connection.

[0024] Optionally, calculating the distribution network short-circuit current based on the global topology connection includes:

[0025] By simulating different fault locations using an iterative algorithm, the short-circuit current values ​​of each branch under different fault scenarios are calculated.

[0026] Optionally, the step of finding the path from the distributed new energy equipment to the equivalent bus based on the topological connection relationship includes:

[0027] Determine the equivalent busbar to which the current outgoing unit belongs;

[0028] Using the equivalent bus as the target, the new energy path of all outgoing units under the equivalent bus is searched cyclically.

[0029] Optionally, the step of setting the relay protection device settings according to the short-circuit current includes:

[0030] The protection device's operating threshold is dynamically set based on the short-circuit current calculation results to ensure accurate fault identification.

[0031] This application also provides a power distribution network relay protection setting device, comprising:

[0032] The module constructs the primary equipment topology connection relationships of the outgoing units of the distribution network;

[0033] The identification module identifies the distributed new energy equipment within the outgoing unit;

[0034] The lookup module searches for the path from the distributed new energy equipment to the equivalent bus based on the topological connection relationship.

[0035] The recording module records the set of primary devices along the path;

[0036] The integration module integrates the primary equipment set with the equivalent bus to form a global topology connection;

[0037] The calculation module calculates the distribution network short-circuit current based on the global topology connection;

[0038] The setting module sets the relay protection device settings based on the short-circuit current.

[0039] This application also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0040] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the above-described method.

[0041] The beneficial effects of this application are:

[0042] This application provides a method for setting relay protection parameters in a distribution network, comprising: constructing the primary equipment topology connection relationship of a distribution network outgoing unit; identifying distributed renewable energy equipment within the outgoing unit; finding the path from the distributed renewable energy equipment to the equivalent bus based on the topology connection relationship; recording the set of primary equipment in the path; integrating the set of primary equipment with the equivalent bus to form a global topology connection; calculating the distribution network short-circuit current based on the global topology connection; and setting the relay protection device parameters based on the short-circuit current. This application simplifies the calculation model and takes into account the impact of renewable energy sources on the same bus by constructing a collaborative topology of multiple outgoing units and identifying renewable energy paths, thereby improving the accuracy of short-circuit current calculation and achieving efficient and accurate setting of relay protection parameters, ensuring stable operation of the power grid. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the setting process for the relay protection settings in the distribution network in this application. Detailed Implementation

[0044] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is to be understood that various forms of implementation of the present disclosure are intended and should not be limited to the embodiments set forth herein. Rather, the embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0045] Please refer to Figure 1 As shown, this application provides a method for setting the relay protection settings in a distribution network, including:

[0046] S101. Construct the primary equipment topology connection relationship of the distribution network outgoing unit;

[0047] First, create new plant information, including the plant's name and voltage level.

[0048] Next, construct the equivalent busbar under the new plant and enter the positive sequence impedance and zero sequence impedance information of the equivalent busbar in both large and small modes.

[0049] Then, new outgoing units are built under the equivalent bus, a distribution network model including photovoltaic and wind power is drawn, and the protection configuration information and impedance parameter information of the equipment are improved.

[0050] In practice, using outgoing line units as the basic unit, an undirected graph model is generated from the power grid diagram based on graph theory algorithms, and a standardized topology connection relationship is constructed for each outgoing line unit. The topology data of each primary device includes the following key information: the unique identifier of the primary device, the unique identifier of its respective outgoing line unit, the device type, the first node number, and the last node number.

[0051] When constructing the topology connection relationship, a primary device is randomly selected as the starting point for numbering. Based on the connection order of the primary devices and the rules of the number of device endpoints, the complete topology connection relationship of all primary devices in the outgoing unit is generated in sequence.

[0052] Clicking save triggers the topology generation process, and this operation is repeated to draw multiple outgoing units under the equivalent bus in sequence.

[0053] S102. Identify the distributed new energy equipment within the outgoing unit;

[0054] After completing the topology construction of the outgoing units, based on the topological connections of the outgoing units, all new energy sets in the outgoing units are located, including distributed new energy devices such as photovoltaics and wind power. Specifically, the identification process involves traversing the device data of the outgoing units to filter out devices whose type is new energy.

[0055] S103. Find the path from the distributed new energy equipment to the equivalent bus based on the topological connection relationship;

[0056] Starting with each distributed renewable energy device and using the connected device nodes as edges, a breadth-first search algorithm is used to find paths to the equivalent bus. The search process ends at the equivalent bus, finding all possible paths from the renewable energy device to the equivalent bus.

[0057] This process is performed after the selected outgoing unit is selected. First, based on the relationship between the outgoing unit and the equivalent bus, the equivalent bus of the selected outgoing unit is found. Then, other outgoing units with the same equivalent bus are searched for paths.

[0058] S104. Record the set of primary devices in the path;

[0059] Record the set of primary equipment and their topological connections along all paths from the new energy equipment to the equivalent bus. To avoid conflicts between node numbers of different outgoing units, a unique identifier for the outgoing unit is added to the node number, effectively preventing node number confusion. After completing the path search for one new energy equipment, continue traversing the next new energy equipment until all new energy equipment in the outgoing units has been traversed.

[0060] The unique identifier refers to a unique code or information string used to distinguish different outgoing units.

[0061] S105. Integrate the primary equipment set with the equivalent bus to form a global topology connection;

[0062] All equipment and topology relationships of the selected outgoing unit, as well as the equivalent bus-new energy path equipment and topology relationships of other outgoing units, are connected and integrated with the equivalent bus as the root node to construct a new topology connection relationship and equipment set.

[0063] Specifically, it includes:

[0064] Based on the equivalent bus to which the selected outgoing unit belongs, find all outgoing units under that bus.

[0065] The selected outgoing line unit loads all equipment and topology relationships, while other outgoing line units only load the equipment and topology relationships on the equivalent bus-new energy path;

[0066] Using the equivalent bus as the root node, these devices are connected together to form a global topology.

[0067] This process constructs a global correlation matrix G = (V, E), where the vertex set V = {v_i|i∈[1,n]} represents n outgoing units, and the edge set E represents the reconfigurable connection relationships between outgoing units.

[0068] S106. Calculate the distribution network short-circuit current based on the global topology connection;

[0069] Based on the integrated global topology, a mathematical model of the distribution network incorporating distributed renewable energy is constructed, and an iterative algorithm is used to accurately calculate the short-circuit current of each branch under different fault scenarios. The specific calculation process simulates different fault locations and calculates the short-circuit current values ​​of the set branches, providing a data foundation for setting the circuit parameters.

[0070] S107. Set the relay protection device settings according to the short-circuit current.

[0071] Based on the calculated short-circuit current, the setting value of the protection device is set.

[0072] Specifically, this includes setting the action threshold of the protection device based on the short-circuit current value to ensure that the setting can accurately identify the fault and make the correct action, thereby ending the entire setting process.

[0073] Furthermore, taking four outgoing units on an equivalent busbar in a distribution network as an example, traditional methods only consider the selected outgoing units in the modeling and setting of the distribution network. However, this method often fails to account for the impact of short-circuit currents from other renewable energy sources on the research object, leading to reduced setting performance. The method proposed in this application effectively solves this problem. Through innovative modeling ideas, this application significantly reduces the size of the aggregation model, thereby greatly improving the efficiency of distribution network model generation. In addition, this application fully considers the impact of renewable energy access on short-circuit current, providing more accurate results when calculating short-circuit current. This provides a more scientific and accurate basis for the setting of distribution network protection devices, significantly improving the adaptability of the settings to the network operating state.

[0074] Furthermore, this application innovatively generates simplified paths from the equivalent busbar to new energy sources through preset rules. While ensuring model accuracy, it effectively solves the problem of excessively large calculation model size in traditional methods, and considers the impact of other outgoing new energy sources on the short-circuit current of this outgoing line. Compared with existing technologies, this application significantly improves the efficiency of distribution network setting calculations, and the protection settings based on new energy short-circuit current calculations enhance selectivity and sensitivity, providing more reliable technical support for the safe and stable operation of the power grid.

[0075] Its technological advantages are mainly reflected in:

[0076] 1) It achieved intelligent topology simplification of the new energy cluster;

[0077] 2) It ensures a balance between computational efficiency and accuracy;

[0078] 3) It can adapt to the access requirements of distributed power sources of different scales.

[0079] Therefore, this application has significant practical value in distribution network setting, and can effectively improve the operational reliability and management level of the distribution network. By applying this application, it ensures that after the integration of distributed renewable energy sources, considering the changes in the overall topology of the distribution network, the relay protection settings can accurately and quickly identify faults and take correct actions, thereby guaranteeing the safe, reliable, and efficient operation of the distribution network.

[0080] This application also provides a power distribution network relay protection setting device, comprising:

[0081] The module constructs the primary equipment topology connection relationships of the outgoing units of the distribution network;

[0082] The identification module identifies the distributed new energy equipment within the outgoing unit;

[0083] The lookup module searches for the path from the distributed new energy equipment to the equivalent bus based on the topological connection relationship.

[0084] The recording module records the set of primary devices along the path;

[0085] The integration module integrates the primary equipment set with the equivalent bus to form a global topology connection;

[0086] The calculation module calculates the distribution network short-circuit current based on the global topology connection;

[0087] The setting module sets the relay protection device settings based on the short-circuit current.

[0088] This application also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0089] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the above-described method.

[0090] The above description of the embodiments is provided to enable those skilled in the art to understand and apply this application. Those skilled in the art will readily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without inventive effort. Therefore, this application is not limited to the above embodiments, and any improvements and modifications made to this application based on the disclosure thereof should be within the scope of protection of this application.

Claims

1. A method for setting relay protection parameters in a distribution network, characterized in that, include: Construct the primary equipment topology connection relationship of the outgoing unit of the distribution network; Identify the distributed new energy equipment within the outgoing unit; Based on the topological connection relationship, find the path from the distributed new energy equipment to the equivalent bus; Record the set of primary devices in the path; The primary equipment set and the equivalent bus are integrated to form a global topology connection; Calculate the distribution network short-circuit current based on the global topology connection; The relay protection device settings are determined based on the short-circuit current.

2. The method for setting the relay protection settings in a distribution network according to claim 1, characterized in that, The step of finding the path from the distributed new energy equipment to the equivalent bus based on the topological connection relationship includes: Starting from the access node of the distributed new energy equipment and using the connection relationship of the primary equipment as the edge, the topology path is traversed through the breadth-first search algorithm until the equivalent bus is reached.

3. The method for setting the relay protection settings in a distribution network according to claim 1, characterized in that, Record the set of primary devices in the path, including: A unique identifier is added to the node number of each outgoing unit to make the node number of different outgoing units globally unique.

4. The method for setting the relay protection settings in a distribution network according to claim 1, characterized in that, Integrating the primary equipment set with the equivalent bus to form a global topology connection includes: Get the topology of all devices in the current outgoing unit; Obtain the equipment topology relationship from the average busbar in other outgoing units to the new energy path; Using the equivalent bus as the root node, the above topological relationships are merged into a global topological connection.

5. The method for setting the relay protection settings in a distribution network according to claim 1, characterized in that, Calculating the distribution network short-circuit current based on the global topology connection includes: By simulating different fault locations using an iterative algorithm, the short-circuit current values ​​of each branch under different fault scenarios are calculated.

6. The method for setting the relay protection settings in a distribution network according to claim 1, characterized in that, The step of finding the path from the distributed new energy equipment to the equivalent bus based on the topological connection relationship includes: Determine the equivalent busbar to which the current outgoing unit belongs; Using the equivalent bus as the target, the new energy path of all outgoing units under the equivalent bus is searched cyclically.

7. The method for setting the relay protection settings in a distribution network according to claim 1, characterized in that, The step of setting the relay protection device settings according to the short-circuit current includes: The protection device's action threshold is dynamically set based on the short-circuit current calculation results to ensure accurate fault identification.

8. A power distribution network relay protection setting device, characterized in that, include: The module constructs the primary equipment topology connection relationships of the outgoing units of the distribution network; The identification module identifies the distributed new energy equipment within the outgoing unit; The lookup module searches for the path from the distributed new energy equipment to the equivalent bus based on the topological connection relationship. The recording module records the set of primary devices along the path; The integration module integrates the primary equipment set with the equivalent bus to form a global topology connection; The calculation module calculates the distribution network short-circuit current based on the global topology connection; The setting module sets the relay protection device settings based on the short-circuit current.

9. An electronic device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed in a computer, causes the computer to perform the method described in any one of claims 1-7.

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