Topological structure simplification system, method and equipment of power system and medium

Abstract

The invention discloses a topological structure simplification system, method and device of a power system and a medium. The system comprises an input module and a simplification module. The input module is used for a user to input data file information of the power system; the simplification module comprises the following steps: constructing a topological structure model according to the data file information and determining an initial reserved node set; determining a to-be-screened node set according to the node features of each node in the topological structure model, removing the to-be-screened node set and the corresponding associated edges from the topological structure model to obtain a plurality of first augmented sub-graphs, and performing hierarchical screening on each first augmented sub-graph based on the first node number to obtain a screening result, determining an elimination node set and a boundary node set based on the screening result and the initial reserved node set; and generating a node admittance matrix based on the elimination node set and the electrical relationship, simplifying the node admittance matrix, and outputting a simplified target topological structure model. According to the invention, the complexity of the power grid topology model can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of power systems, and in particular to a system, method, device and medium for simplifying the topology of a power system. Background Art

[0002] With the continuous development of power systems, AC / DC hybrid power grids are becoming increasingly large and complex. When conducting operational analysis, fault diagnosis, planning, and control research on these power grid topology models, they often face tremendous computational pressure. This not only results in low computational efficiency, but also can lead to excessive consumption of computing resources due to the large amount of data, making it difficult to obtain accurate analysis results. Furthermore, complex power grid topology models hinder researchers from quickly and accurately grasping the overall operating status and key characteristics of the power grid, thus affecting the accuracy of analysis results. Therefore, to improve the efficiency and accuracy of power grid analysis while reducing computational costs and resource consumption, it is particularly important to rationally simplify the power grid topology model.

[0003] Existing power grid topology simplification methods typically establish a full-system model based on the grid node admittance matrix. Based on research requirements, the nodes are divided into a set of boundary nodes to be retained and a set of internal nodes to be eliminated. Block matrix theory is then used to decompose the admittance matrix into retained node sub-blocks, internal node sub-blocks, and mutual admittance coupling sub-blocks. An improved Gaussian elimination method is then applied to reduce the internal node matrix order. However, this method employs a relatively sparse and dispersed selection of retained nodes, while simultaneously eliminating subnets formed by node connections and excessive retained node connections. This results in increased network topology complexity after simplification and a loss of the sparsity and structural characteristics of the original grid, making it difficult to meet the requirements of efficient analysis and precise control. Summary of the Invention

[0004] The present invention provides a system, method, device and medium for simplifying the topology structure of an electric power system to reduce the complexity of the power grid topology model and meet the needs of efficient analysis and precise control.

[0005] An embodiment of the present invention provides a method for simplifying the topology of a power system, comprising: an input module and a simplification module;

[0006] The input module is used for allowing the user to input data file information of the power system and transmit the data file information to the simplification module;

[0007] The simplification module includes: a first determination unit, a second determination unit and a simplification element;

[0008] The first determining unit is configured to construct a topology structure model according to the data file information and determine an initial reserved node set of the topology structure model;

[0009] The second determination unit is used to determine a set of nodes to be filtered according to the node characteristics of each node in the topological structure model, and remove the set of nodes to be filtered and the corresponding associated edges from the copy of the topological structure model to obtain several subgraphs, determine a corresponding first augmented subgraph based on each of the subgraphs, perform hierarchical screening on each of the first augmented subgraphs based on the first number of nodes to obtain a screening result, and determine a target retained node set based on the screening result and the initial retained node set, and determine an eliminated node set and a boundary node set based on the target retained node set, wherein the first number of nodes is the number of retained nodes that have connecting edges between each of the first augmented subgraphs and the initial retained node set;

[0010] The simplification element is used to generate a node admittance matrix based on the eliminated node set and the electrical relationship, and simplify the node admittance matrix to output the simplified target topology structure model, wherein the electrical relationship is the electrical connection relationship between the eliminated node set and the boundary node set.

[0011] The embodiment of the present invention constructs a topology model by reading the power system data file, which can clearly present the overall structure and connection relationship of the power grid; by determining the initial retained node set, a basic framework can be set for the subsequent simplification process, ensuring that the simplified model can retain the most important parts of the power grid; by removing the node set to be filtered and the corresponding associated edges from the copy of the topology model, the number of nodes and connection relationships in the topology model are directly reduced, and the obtained subgraphs and subsequent hierarchical screening based on the first number of nodes can further remove relatively minor parts of the power grid topology analysis and understanding, retain key nodes and connection relationships, thereby effectively reducing the complexity of the power grid topology model; after generating a node admittance matrix based on eliminating the node set and electrical relationship, it is simplified, and the complex power grid electrical connection relationship can be simplified and expressed in matrix form, removing redundant electrical parameters and connection information, further reducing the complexity of the power grid topology model at the electrical parameter level, making the mathematical model of the power grid more concise and clear, and thus can be more efficiently used for various analysis and calculations of the power grid, providing a simpler and more effective model foundation for subsequent power grid analysis and precise control. Compared with the existing technology, this application can reduce the complexity of the power grid topology model and meet the needs of efficient analysis and precise control.

[0012] Furthermore, the second determining unit includes a calculating subunit and a processing subunit:

[0013] The calculation subunit is configured to calculate the out-of-line degree and the second node number of each node in the topological structure model, wherein the node characteristics include the out-of-line degree and the second node number, and the second node number is the number of retained nodes having connecting edges with the initial retained node set;

[0014] The processing sub-unit is used to add the node to the set of nodes to be screened if the out-of-line degree corresponding to each node is greater than a first preset threshold and the second number of nodes is greater than a second preset threshold, until all nodes in the topological structure model are processed and the set of nodes to be screened is determined.

[0015] In this way, by calculating the outgoing degree and the second number of nodes of each node, it is possible to accurately find nodes in the topology model with relatively simple connection relationships and fewer associations with the initial retained node set. By adding nodes with an outgoing degree greater than a first preset threshold and a number of retained nodes greater than a second preset threshold to the set of nodes to be screened, the number of nodes and the number of connecting lines in the topology model can be directly reduced, making the power grid topology model more concise.

[0016] Furthermore, the second determining unit further includes: a first searching subunit, a second searching subunit and an adding subunit:

[0017] The first search sub-unit is configured to traverse the nodes in each of the subgraphs and search the topology model for associated nodes in the initial retained node set connected to each of the subgraph nodes to determine an associated node set;

[0018] The second search subunit is used to search for the associated edges between the associated node set and each subgraph node in the topological structure model to obtain an associated edge set;

[0019] The adding sub-unit is used to add the associated node set and the associated edge set to the corresponding subgraph to obtain the corresponding first augmented subgraph.

[0020] In this way, by searching for associated nodes in the initial retained node set connected to each subgraph node in the topological structure model, determining the associated node set, and searching for the corresponding associated edge set, the key retained nodes and connection relationships related to the current subgraph can be accurately located, reducing the number of nodes and edges that need to be considered in subsequent processing. The associated node set and the associated edge set are added to the corresponding subgraph to form the first augmented subgraph, so that each subgraph removes redundant and minor connections while retaining its closely connected parts with the initial retained node set.

[0021] Furthermore, the second determining unit further includes: a traversing subunit and a screening subunit, specifically:

[0022] The traversal sub-unit is used to determine the number of first nodes in each of the first augmented subgraphs that belong to the initial retained node set and have connecting edges with other nodes in the corresponding first augmented subgraph;

[0023] The screening subunit is configured to: if the first node number is less than a third preset threshold, traverse all nodes in each first augmented subgraph, and determine whether there is a breakpoint in the first augmented subgraph; if there is a breakpoint, remove all breakpoints and corresponding associated edges in the copy of the first augmented subgraph to obtain a plurality of second augmented subgraphs; and count a third node number of the initial reserved node set included in each second augmented subgraph, and if the third node number meets a preset condition, remove the corresponding node from each second augmented subgraph until no new breakpoint is generated in each second augmented subgraph or all nodes are traversed, to obtain a plurality of screening results.

[0024] In this way, by performing hierarchical screening on each first augmented subgraph, parts that are relatively unimportant for analysis and understanding of the power grid topology structure can be further removed, and key nodes and connection relationships are reserved, thereby effectively reducing the complexity of the power grid topology model.

[0025] Further, the screening subunit specifically includes:

[0026] If the third node number is 0, all nodes in the second augmented subgraph are removed.

[0027] If the third node number is 1, all nodes except the reserved node in the second augmented subgraph and the corresponding associated edges are removed, and new reserved associated edges are constructed between the reserved nodes.

[0028] In this way, the complex connection relationships inside the augmented subgraph can be greatly simplified, unnecessary details can be removed, and the power grid topology model is more concise and focuses on nodes and connection paths that are important for the overall power grid.

[0029] Further, the simplification unit includes a first determination subunit, a second determination subunit, and a third determination subunit.

[0030] The first determination subunit is configured to determine electrical parameters of each node in the elimination node set based on the data file information, and construct a first self-impedance matrix corresponding to the electrical parameters, wherein the electrical parameters include loads and power compensation devices.

[0031] The second determination subunit is configured to determine line parameters and transformer parameters between the elimination node set and the boundary node set based on the data file information, determine a mutual-impedance matrix of the elimination node set and the boundary node set based on resistance and reactance, and determine a second self-impedance matrix of the boundary node set based on the line parameters and the transformer parameters, wherein the line parameters include the resistance and the reactance.

[0032] The third determining subunit is configured to determine a corresponding node admittance matrix based on the first self-admittance matrix, the mutual admittance matrix, and the second self-admittance matrix.

[0033] By converting these parameters into the form of mutual admittance matrices and self-admittance matrices, the complex electrical connection relationship of the power grid can be clearly presented. By integrating the information of the three matrices, a complete and concise mathematical model can be constructed to represent the complex power grid system, so that subsequent power grid analysis and calculations can be carried out in a more concise and efficient mathematical framework, thereby greatly improving the efficiency of analysis and calculation.

[0034] Furthermore, the simplification element includes a simplification subunit and a fourth determination subunit, specifically:

[0035] The simplification subunit is used to process the node admittance matrix by using the Kron simplification method to obtain a simplified matrix;

[0036] The fourth determining subunit is configured to convert the simplified matrix into electrical parameters of the boundary node set, and determine a target topology structure model based on the boundary parameters.

[0037] By simplifying in this way, the complex electrical connection relationship of the power grid can be simplified and expressed in matrix form, eliminating redundant electrical parameters and connection information, further reducing the complexity of the power grid topology model at the electrical parameter level, making the mathematical model of the power grid more concise and clear, and thus able to be more efficiently used for various analysis and calculations of the power grid, providing a simpler and more effective model basis for subsequent power grid analysis and precise control.

[0038] Another embodiment of the present invention further provides a method for simplifying the topology of a power system, comprising:

[0039] Constructing a topology structure model according to the data file information input by the user, and determining an initial reserved node set of the topology structure model;

[0040] Determine a set of nodes to be filtered according to the node characteristics of each node in the topological structure model, remove the set of nodes to be filtered and the corresponding associated edges from the copy of the topological structure model to obtain several subgraphs, determine a corresponding first augmented subgraph based on each of the subgraphs, perform hierarchical screening on each of the first augmented subgraphs based on a first number of nodes to obtain a screening result, determine a target retained node set based on the screening result and the initial retained node set, determine an eliminated node set and a boundary node set based on the target retained node set, wherein the first number of nodes is the number of retained nodes having connecting edges between each of the first augmented subgraphs and the initial retained node set;

[0041] A node admittance matrix is ​​generated based on the eliminated node set and the electrical relationship, and the node admittance matrix is ​​simplified to output a simplified target topology structure model, wherein the electrical relationship is an electrical connection relationship between the eliminated node set and the boundary node set.

[0042] The embodiment of the present invention constructs a topology model by reading the power system data file, which can clearly present the overall structure and connection relationship of the power grid; by determining the initial retained node set, a basic framework can be set for the subsequent simplification process, ensuring that the simplified model can retain the most important parts of the power grid; by removing the node set to be filtered and the corresponding associated edges from the copy of the topology model, the number of nodes and connection relationships in the topology model are directly reduced, and the obtained subgraphs and subsequent hierarchical screening based on the first number of nodes can further remove relatively minor parts of the power grid topology analysis and understanding, retain key nodes and connection relationships, thereby effectively reducing the complexity of the power grid topology model; after generating a node admittance matrix based on eliminating the node set and electrical relationship, it is simplified, and the complex power grid electrical connection relationship can be simplified and expressed in matrix form, removing redundant electrical parameters and connection information, further reducing the complexity of the power grid topology model at the electrical parameter level, making the mathematical model of the power grid more concise and clear, and thus can be more efficiently used for various analysis and calculations of the power grid, providing a simpler and more effective model foundation for subsequent power grid analysis and precise control. Compared with the existing technology, this application can reduce the complexity of the power grid topology model and meet the needs of efficient analysis and precise control.

[0043] Another embodiment of the present invention also provides a terminal device, including: a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the steps of the method for simplifying the topology structure of the power system as described in the present invention.

[0044] Another embodiment of the present invention further provides a computer-readable storage medium item, comprising: a stored computer program, which controls the device where the computer-readable storage medium is located to execute the steps of the method for simplifying the topology structure of the power system as described in the present invention when the computer program is running. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0046] Figure 1This is a structural diagram of an embodiment of a simplified topology system of a power system provided by the present application;

[0047] Figure 2 This is a schematic structural diagram of an embodiment of a simplified module provided by this application;

[0048] Figure 3 It is a schematic diagram of subgraph augmentation provided by this application;

[0049] Figure 4 This is a comparison diagram of the traditional method provided by this application and the simplified result of this application;

[0050] Figure 5 This is a flow chart of an embodiment of a method for simplifying the topology structure of a power system provided in this application. DETAILED DESCRIPTION

[0051] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0053] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0054] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0055] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0056] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0057] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0058] The scale and structural complexity of AC / DC hybrid power grids are constantly increasing, but existing power grid topology simplification methods have shortcomings in node selection and network complexity after simplification, making it difficult to simultaneously meet the needs of efficient analysis and precise control. There is an urgent need for better simplification methods to improve efficiency and accuracy and reduce computational costs.

[0059] See also Figure 1 , in order to reduce the complexity of the power grid topology model, an embodiment of the present invention provides a power system topology simplification system, including: an input module 100 and a simplification module 200;

[0060] The input module 100 is used for allowing the user to input data file information of the power system and transmit the data file information to the simplification module 200;

[0061] In some embodiments, a user-friendly interface is developed, which may be a graphical user interface (GUI) or a command line interface (CLI), for receiving data file information of the power system (i.e., the AC / DC power grid to be studied) input by the user. For example, the user can select a data file stored in a local or network path through a file selection dialog box.

[0062] It should be noted that the data file information contains relevant data on various facilities in the power grid and their connection relationships, such as information on key facilities such as substations, power plants, load nodes, virtual nodes, as well as the connection status of transmission facilities such as AC transmission lines, DC transmission lines, and transformers.

[0063] It should be noted that after the user selects or inputs the data file information, the system needs to verify the validity of the file, ensure that the file exists and is correctly formatted, and then preprocess the data to extract the parameters (such as node information, line impedance, transformer parameters, etc.) and connection relationships of the power grid elements. The specific verification and extraction are not the focus of the present application, and therefore will not be expanded here.

[0064] Please refer to Figure 2 The simplification module 200 includes a first determination unit 2001, a second determination unit 2002, and a simplification unit 2003.

[0065] The first determination unit 2001 is configured to construct a topological structure model according to the data file information, and determine an initial reserved node set of the topological structure model.

[0066] In some embodiments, the topological structure model is constructed according to the data file information, specifically: according to the read data file, a weighted network graph G=(V,E) is constructed to represent the connection relationship between each site in the power system. Among them, the node set V covers all key facilities in the power grid, including substations of different voltage levels, various power plants, load nodes, and virtual nodes, etc.; the edge set E includes all transmission facilities connecting the above nodes, i.e. AC transmission lines, DC transmission lines, transformers, etc.

[0067] In some embodiments, the initial reserved node set of the topological structure model is determined, specifically: according to the specific research needs, the nodes that need to be reserved for research are added to the initial reserved node set saved_nod. At the same time, in addition to the nodes that need to be reserved for research, DC converter nodes, power plant nodes, and new energy station nodes, etc. are also added to the original reserved node set saved_nodes as nodes that must be reserved in the equivalent process.

[0068] It should be noted that the DC converter nodes, power plant nodes, and new energy station nodes, etc. as nodes that must be reserved in the equivalent process often have special roles or important electrical characteristics in the operation and analysis of the power grid, and will have a key impact on the equivalent and simplification process of the power grid, so they must be ensured to be reserved in the subsequent simplification process. The selection of other nodes will be based on the connection relationship between other nodes and the initial reserved node set saved_nodes.

[0069] The second determining unit 2002 is used to determine a set of nodes to be filtered according to the node characteristics of each node in the topological structure model, and remove the set of nodes to be filtered and the corresponding associated edges from the copy of the topological structure model to obtain several subgraphs, determine a corresponding first augmented subgraph based on each of the subgraphs, perform hierarchical screening on each of the first augmented subgraphs based on the first number of nodes to obtain a screening result, and determine a target retained node set based on the screening result and the initial retained node set, and determine an eliminated node set and a boundary node set based on the target retained node set, wherein the first number of nodes is the number of retained nodes that have connecting edges between each of the first augmented subgraphs and the initial retained node set;

[0070] The second determining unit 2002 includes a calculating subunit and a processing subunit:

[0071] The calculation subunit is configured to calculate the out-of-line degree and the second node number of each node in the topological structure model, wherein the node characteristics include the out-of-line degree and the second node number, and the second node number is the number of retained nodes having connecting edges with the initial retained node set;

[0072] In some embodiments, first, when constructing a topology model G according to the power grid data file information, an adjacency matrix A is generated at the same time, wherein the adjacency matrix A indicates whether there is a connection relationship between the nodes in the topology model; then, all nodes in the topology model G are traversed, and if there is an edge connecting node i and node j, the corresponding position A in the adjacency matrix A is added. ij The value of is set to 1, otherwise it is set to 0; then, for the currently visited node i, determine whether node i belongs to the reserved node set. If node i belongs to the initial reserved node set, it means that the node must be retained, and there is no need to calculate its outgoing degree and the number of connected reserved nodes. It is directly retained in the topology model G as the basis for subsequent analysis and processing. If node i does not belong to the initial reserved node set, that is, Then it is necessary to calculate the node characteristics of the node, that is, to calculate the linear dimension d i and the second node number d is .

[0073] In some embodiments, the line length d i Refers to the number of edges connected to node i, reflecting the connection density of node i in the power grid, where the outgoing line degree d i The calculation process is: traverse the i-th row of the adjacency matrix A, count the number of elements with a value of 1, and get the out-of-line degree d of node i i , the relevant calculation formula is: Where, d i is the line degree, A is the adjacency matrix of the topological structure model G, Aij = 1 indicates that there is a connection edge between node i and node j, otherwise A ij = 0, n is the number of nodes of the topological structure model G.

[0074] In some embodiments, the second number of nodes d is refers to the number of reserved nodes that have connection edges with the initial reserved node set, wherein the second number of nodes d is is calculated as follows: for each node i in the topological structure model G, the number of nodes belonging to the initial reserved node set saved_nodes that have connection edges with node i is counted by traversing the ith row in the adjacency matrix A, and the relevant calculation formula is: In the formula, d is is the second number of nodes, A ij = 1 indicates that there is a connection edge between node i and node j, otherwise A ij = 0.

[0075] It should be noted that the first, second and third do not represent the order of precedence and can be understood as nouns, wherein the first number of nodes refers to the number of reserved nodes that have connection edges with the initial reserved node set saved_nodes, the second number of nodes refers to the number of reserved nodes that have connection edges with the initial reserved node set saved_nodes for each node in the topological structure model, and the second number of nodes refers to the number of nodes in the initial reserved node set saved_nodes included in each second augmented subgraph.

[0076] The processing subunit is configured to add the node to the to-be-screened node set if the outgoing degree corresponding to the node is greater than a first preset threshold and the second number of nodes is greater than a second preset threshold, and determine the to-be-screened node set after processing all nodes in the topological structure model.

[0077] In some embodiments, after calculating the outgoing degree d i and the second number of nodes d is , according to the size and complexity of the specific power grid, a first preset threshold (such as 3) corresponding to the outgoing degree d i and a second preset threshold (such as 2) corresponding to the second number of nodes d is are set, which will be used as the basis for judging whether a node should be added to the to-be-screened node set; then, for each node, it is checked whether the outgoing degree d i is greater than the first preset threshold (such as 3) and the number of reserved nodes d isIs it greater than a second preset threshold (such as 2)? If both conditions are met, the node is added to the set of nodes to be screened, thereby quickly filtering out some nodes that obviously do not meet the retention conditions, reducing the amount of calculation in the subsequent screening process; according to the above steps, all nodes in the power grid topology model G are processed in turn until all nodes have passed the preliminary screening and the final set of nodes to be screened is determined. This set includes nodes that are considered to have a significant impact on network performance during the preliminary screening process. These nodes will be analyzed and screened in more detail later to determine the final set of retained nodes.

[0078] It should be noted that, in order to facilitate subsequent analysis, the topology model G needs to be copied into graph H. Graph H will be used specifically to simulate the node elimination process, that is, by removing nodes one by one and observing the changes in the network topology, if the outgoing degree d of node i i ≤2, then eliminating node i will not increase the complexity of the network, and they can be directly screened out of the set of nodes to be screened, that is, not put into the set of nodes to be screened, to reduce the amount of calculation in the subsequent screening process. Therefore, node i can be simulated and eliminated in graph H. Specifically, if the outgoing degree d i =1, indicating that there is only one node (denoted as node j) connected to node i in graph H. Simply removing node i and the associated edge (i, j) in graph H can simulate the elimination of node i in graph H. If d i = 2, indicating that two nodes (denoted as nodes u and v) are connected to node i in graph H. Node i needs to be simulated eliminated by removing node i and the edges (i, u) and (i, v) from graph H and adding the edge (u, v). Using these conditions, we perform a preliminary screening of the nodes in graph H, completing the processing of node i. The remaining nodes with connection characteristics are temporarily retained in graph H for further simplification in subsequent steps.

[0079] It should be noted that only the outgoing degree d is considered when performing node screening. i The reason is: the second node number d is The set of retained nodes directly connected to node i is a subset of the set of directly connected nodes, so d is ≤d i , when d i =2, d is Can be 0, 1, 2, d is = 0 means that node i is directly connected to two other nodes to be screened, d is =1 means that node i is directly connected to one retained node and one node to be screened, d is = 2 Node i is directly connected to 2 retained nodes. In these cases, eliminating node i will cause the two connected nodes to establish a new edge while eliminating node i and the edge associated with node i, which will not increase the complexity and is also applicable to di = 2, the simulation elimination method is shown in FIG. 2, so d is is not required to be eliminated. i = 1, the same as d i = 2, both do not need to eliminate d is = 1, the same as d i = 2, and d is = 3, it means that node i is an important connection node, and its elimination will bring potential higher complexity, so it needs to be reserved, especially the two cases of (d i = 2, d is = 2) and (d i = 3, d is = 2) need to be distinguished, the former means that node i is separated into an 'isolated' node to be eliminated by two reserved nodes, and it is not connected to other nodes to be eliminated, and its elimination will not increase the complexity; while the latter means that node i is connected to two reserved nodes and also connected to a node to be screened, and its elimination may increase greater complexity, in addition, this node connection feature generally corresponds to the connection relationship between the power plant main site and the power generation node and the power grid, and its elimination will make the power generation nodes connected, which does not conform to the actual connection characteristics of the power grid. For other cases, d i , d is cannot be directly screened according to the node characteristics, so the node characteristics need to be further screened through subsequent steps.

[0080] In this way, by calculating the outgoing degree of each node and the second node number, the nodes with relatively simple connection relationship and less association with the initial reserved node set in the topological structure model can be accurately found out, and by adding the nodes with the outgoing degree greater than the first preset threshold and the reserved node number greater than the second preset threshold to the node set to be screened, the number of nodes and the number of connection lines in the topological structure model can be directly reduced, so that the power grid topology model is more concise.

[0081] In some embodiments, the set of nodes to be screened and the corresponding associated edges are removed from the copy of the topological structure model to obtain a plurality of subgraphs, specifically: all nodes in the set of nodes to be screened and the edges associated with these nodes are removed from the copy of the topological structure model (i.e., the copy of the topological structure model), that is, similar to deleting a specific station and its directly connected lines from the network, thereby dividing the network into multiple unconnected parts, thereby obtaining a plurality of subgraphs net, which are closely connected internally but not connected to each other, forming a set of subgraphs nets = {net i |i = 1, 2,..., N}.

[0082] In some embodiments, the second determining unit 2002 further includes: a first searching subunit, a second searching subunit, and an adding subunit:

[0083] The first search sub-unit is configured to traverse the nodes in each of the subgraphs and search the topology model for associated nodes in the initial retained node set connected to each of the subgraph nodes to determine an associated node set;

[0084] In some embodiments, all nodes in each subgraph nets are traversed in turn in the topology model. While traversing each subgraph nets node, the neighbor node of the node is checked to see if it is a node in the initial saved node set saved_nodes. If such a neighbor node exists, the neighbor node is recorded as the associated node between the current subgraph node and the initial saved node set saved_nodes. Through such a checking and recording process, an associated node set V can be gradually constructed. sk , which contains all the initially retained nodes connected to the current subgraph node. After completing the neighbor node check for a subgraph node, the found associated nodes are added to the associated node set. For each subgraph node, the above steps are repeated until all subgraph nodes have been traversed. The final associated node set V sk , which fully represents the connection relationship between the current subgraph and the initial set of retained nodes. Specifically, for each node u in saved_nodes, determine whether there is an edge (u,v) in the topological structure model, where v is the subgraph net k For any node in , if there is such an edge, add node u to the associated node set V sk The relevant formula is: Where V sk is the set of associated nodes; and Representation diagram The node set and edge set of the initial retained node set saved_nodes; v is the subgraph net k A node of ; G is the topological structure model.

[0085] The second search subunit is used to search for the associated edges between the associated node set and each subgraph node in the topological structure model to obtain an associated edge set;

[0086] In some embodiments, for each subgraph nets, each node in the subgraph is traversed to check its relationship with the associated node set V skSpecifically, we can check the adjacency matrix or directly traverse the neighbor list of the node to determine whether there is an edge between the two nodes. If there is a connecting edge, the corresponding edge is recorded and added to the associated edge set E. sk Specifically, continue to search for the edge (u, v) in the topology model G. For the edge (u, v) in the topology model G, if the node u is a subgraph net k If the node in is a node and node v is a node in saved_nodes, then add the edge (u,v) to the associated edge set E sk The relevant formula is: E sk ={(u,v)∈E(G)|u∈V(net k )∧v∈saved_nodes}; where E sk is the set of associated edges; and Representation diagram The node set and edge set of u; u is the subgraph net k A node; v is a node in the initial reserved node set saved_nodes; G is the topological structure model.

[0087] The adding sub-unit is used to add the associated node set and the associated edge set to the corresponding subgraph to obtain the corresponding first augmented subgraph.

[0088] In some embodiments, the associated node set V sk and the associated edge set E sk Add to the corresponding subgraph nets to get the corresponding first augmented subgraph, specifically add the subgraph net k The node set V(net k ) and the associated node set V sk Merge to form a new node set V(aug_net k ), and the subgraph net k The edge set E(net k ) and the associated edge set E sk Merge to form a new edge set E(aug_net k ), get the first augmented subgraph aug_net k , the relevant formula is aug_net k =(V(aug_net k )∪V sk ,E(aug_net k )∪E sk ); Repeat the above steps until all subgraphs net k ∈net sAll processing is completed, and the complete first augmented subgraph set aug_net is obtained s , to achieve amplification.

[0089] It should be noted that because the subgraph net k It is one of the multiple subgraphs formed by deleting the set to be filtered from the copy H of the topological structure model, and its network does not contain the nodes in the set of nodes to be filtered, because the subsequent steps need to be based on the subgraph net k The connection relationship between the nodes in the initial reserved node set saved_nodes is carried out, so in this step, the subgraph net k Expanded to the first augmented subgraph aug_net k To supplement this topology information, please refer to Figure 3 , Figure 3 is a schematic diagram of subgraph augmentation provided by this application, wherein: Figure 3 (a) In the net k It is the area surrounded by dotted lines, including 4 subgraphs and 4 blue circles representing nodes. Figure 3 (b) The first augmented subgraph aug_net k Schematic diagram of aug_net k It is the area enclosed by the dotted line plus the 8 retained nodes connected to the outside.

[0090] In this way, by searching for associated nodes in the initial retained node set connected to each subgraph node in the topological structure model, determining the associated node set, and searching for the corresponding associated edge set, the key retained nodes and connection relationships related to the current subgraph can be accurately located, reducing the number of nodes and edges that need to be considered in subsequent processing. The associated node set and the associated edge set are added to the corresponding subgraph to form the first augmented subgraph, so that each subgraph removes redundant and minor connections while retaining its closely connected parts with the initial retained node set.

[0091] In some embodiments, the second determining unit further includes: a traversal subunit and a screening subunit, specifically:

[0092] The traversal sub-unit is configured to determine the number of first nodes in each of the first augmented subgraphs that belong to the initial retained node set and have connecting edges with other nodes in the corresponding first augmented subgraph;

[0093] In some embodiments, each first augmented subgraph aug_net is traversed k , check the nodes that belong to the initial retained node set saved_nodes, and determine whether the node has a connection edge with other nodes in the first augmented subgraph, specifically: count each augmented subgraph aug_ne kthe first number of nodes D in the initial reserved node set saved_nodes contained in t netk , and the relevant calculation formula is D netk = |V(aug_net k )∩saved_nodes|.

[0094] The screening subunit is configured to, if the first number of nodes is less than a third preset threshold, traverse all nodes in each of the first augmented subgraphs, and determine whether there is a breakpoint in the first augmented subgraph. If there is a breakpoint, all breakpoints and associated edges in the copy of the first augmented subgraph are removed to obtain a plurality of second augmented subgraphs, and a third number of nodes in the initial reserved node set contained in each of the second augmented subgraphs is counted. If the third number of nodes satisfies a preset condition, the corresponding node is removed from each of the second augmented subgraphs until no new breakpoint is generated in each of the second augmented subgraphs or all nodes are traversed, and a plurality of screening results are obtained.

[0095] In some embodiments, first, it is determined whether the first number of nodes D netk is less than a third preset threshold (such as 3). If the first number of nodes D netk in the initial reserved node set contained in the first augmented subgraph is less than or equal to 3, that is, D netk ≤3, further screening of the nodes in the first augmented subgraph aug_net k is considered at this time. Second, the nodes in each of the first augmented subgraphs aug_net k are traversed, and it is determined whether there is a breakpoint in the first augmented subgraph aug_net k . If there is a breakpoint, all breakpoints in aug_net k are found, and all the breakpoints in the first augmented subgraph aug_net k are traversed. When the breakpoint i is accessed, a copy aug_net k of the accessed first augmented subgraph aug_net ki is established, the breakpoint i and the associated edges in the copy aug_net ki are removed, and when all the breakpoints and the associated edges are removed, the copy aug_net ki can be divided into a plurality of connected second augmented subgraphs sub_nets ki . Subsequently, the second augmented subgraphs sub_nets ki are traversed, and a third number of nodes d kij in the initial reserved node set saved_nodes contained in each of the second augmented subgraphs sub_net kij is counted again, and it is determined whether the third number of nodes d kij satisfies a preset condition. If the third number of nodes dkij If it is zero or one, the preset condition is met, and the second augmented subgraph sub_nets ki The nodes that do not belong to the initial retained node set are removed, and the final screening result V(H) is obtained. This process continues until no new breakpoints appear or all nodes are traversed.

[0096] In some embodiments, the screening sub-unit is specifically as follows: if the third number of nodes is 0, all nodes in the second augmented subgraph are removed; if the third number of nodes is 1, all nodes and corresponding associated edges in the second augmented subgraph except the retained nodes are removed, and new retained associated edges are constructed between the retained nodes. Specifically, when the third number of nodes is d kij = 0, directly remove the second augmented subgraph sub_net kij The nodes and associated edges that do not belong to the initial set of retained nodes saved_nodes are removed; when the third node number d kij =1, then the second augmented subgraph sub_net kij Contains a retained node m, removes all nodes and associated edges in this subgraph except the retained node m, and establishes a new edge (i, m).

[0097] It should be noted that when D netk ≤3, this indicates that the nodes in the first augmented subgraph are eliminated. The network connection relationship complexity increases and the actual connection characteristics of the composite power grid are combined, so all nodes in the first augmented subgraph can be eliminated.

[0098] It should be noted that when node i is accessed, the accessed subgraph aug_net is established k Replica aug_net ki , move node i and the associated edges out of the second augmented subgraph aug_net ki ; At this time, judge the second augmented subgraph aug_net ki Is there a breakpoint? If so, find the second augmented subgraph aug_net ki Traverse these breakpoints, and when the breakpoint m is reached, the second augmented subgraph aug_net is established ki A copy of aug_net kim , in aug_net kim Remove the breakpoint m and the associated edges to generate the third augmented subgraph sub_nets kim , judge the third augmented subgraph sub_nets kim Each subgraph sub_net kimjWhether to include the nodes in the initial reserved node set saved_nodes. If not, sub_net is added to the copy of the topology model. kimj The nodes contained in are simulated and eliminated, that is, the third augmented subgraph sub_net is removed from the copy of the topological structure model kimj The nodes and associated edges in , and new edges (i, m) are established. This process continues until no new breakpoints appear or all nodes are traversed.

[0099] In this way, by performing hierarchical screening on each of the first augmented subgraphs, relatively unimportant parts for analyzing and understanding the power grid topology structure can be further removed, while retaining key nodes and connection relationships, thereby effectively reducing the complexity of the power grid topology model.

[0100] This can greatly simplify the complex connection relationships within the augmented subgraph, remove unnecessary details, make the power grid topology model more concise, and focus on the nodes and connection paths that are important to the overall power grid.

[0101] In some embodiments, a target retained node set is determined based on the screening result and the initial retained node set, and an eliminated node set and a boundary node set are determined based on the target retained node set. Specifically, after determining the screening result V(H), the screening result V(H) of the copy of the topological structure model is aggregated with the initial retained node set saved_nodes to obtain the target retained node set saved_buses; at this time, the other nodes of the topological structure model are the eliminated node set throw_buses; at this time, the target retained node set saved_buses is traversed to determine the types of all neighboring nodes connected to the visited node j in the topological structure model. If there is a neighboring node that is a node in the eliminated node set throw_buses, then the node j is added to the boundary node set edge_buses, otherwise it is added to the internal node set inner_buses. Subsequently, the nodes in the eliminated node set and the nodes in the boundary node set can be numbered, where the eliminated nodes are numbered first and the boundary nodes are numbered later.

[0102] It should be noted that the initial retained node set is the basis of the target retained node set, which includes all nodes in the initial retained node set and is expanded on this basis. The set to be screened is the complement of the initial retained node set, which includes all nodes that have not been determined to be required to be retained. These nodes are further analyzed and screened by the second determination unit, and the nodes that meet the retention conditions are eventually added to the target retained node set, while the nodes that do not meet the retention conditions are determined as the elimination node set. In the whole process, the initial retained node set plays a core guiding role, ensuring that the key nodes of the power grid are retained, and the processing of the set to be screened is a key step in achieving topology simplification.

[0103] The simplification element 2003 is used to generate a node admittance matrix based on the eliminated node set and the electrical relationship, and simplify the node admittance matrix to output the simplified target topology structure model, wherein the electrical relationship is the electrical connection relationship between the eliminated node set and the boundary node set.

[0104] In some embodiments, the simplification unit 2003 includes a first determining subunit, a second determining subunit, and a third determining subunit:

[0105] The first determining subunit is configured to determine electrical parameters of each node in the elimination node set and the connection lines between the nodes and the elimination nodes based on the data file information, and construct a corresponding first auto-admittance matrix based on the electrical parameters, wherein the electrical parameters include parameters of a load, a power compensation device, and a line / transformer connected to the elimination node;

[0106] In some embodiments, a professional power grid analysis software or a custom parsing program is used to read the power grid data file to obtain various basic information of the power grid, including node type (such as substation, power plant, load node, etc.), connection relationship (such as transmission line, transformer, etc.) and electrical parameters of each node (such as load power, compensation device parameters, etc.), to determine the electrical parameters of each node in the node set, such as load power (such as the active power P of the node), and to determine the electrical parameters of each node in the node set, such as load power (such as the active power P of the node). iload and reactive power P iload , indicating the load size of the node), compensation device parameters (such as the active power value P consumed by the active power compensation device at the rated power of node i) ishunt The inductive reactive power value Q provided by the reactive power compensation device at the rated power of node i is ishunt ), the voltage value U at node i i And voltage reference value U B and power reference value S B Then, the first conversion formula is used to convert the load parameter of node i into the contribution value Y to the self-admittance of the node i_load, wherein the first conversion formula is: Where Y i_load is the contribution of the load of node i to the normalized self-admittance of node i; S i is the power value of node i; U i is the voltage value of node i; U B is the voltage reference value; S B is the power reference value; j is the imaginary unit; P iload The active power value of the load at node i; Q iload is the reactive power value of the load at node i; and the contribution value Y of the power compensation device at node i to the self-admittance is calculated using the second conversion formula i_shunt , wherein the second conversion formula is: Y i_shunt =(P ishunt +jQ ishunt ) / S B Where, Y i_shunt P is the contribution value of the power compensation device connected to node i to the normalized self-admittance of node i; ishunt Q is the active power consumed by the active power compensation device connected to node i at the rated power of node i; ishunt S is the inductive reactive power value provided by the reactive power compensation device connected to node i at the rated power of node i; B is the power reference value; j is the imaginary unit; the contribution value Y of the line connected to node i to the self-admittance is calculated using the third conversion formula i_lineij , wherein the third conversion formula is: Where Y i_lineij is the normalized contribution of the line between nodes i and j to the self-admittance of node i; j is an imaginary unit; y ij_i is the per-unit value of the earth admittance of the line between nodes i and j at node i; r ij and x ij The per-unit values ​​of the resistance and reactance of the line between nodes i and j are respectively; the contribution value Y of the transformer connected to node i to the self-admittance is calculated using the fourth conversion formula i_tranij , wherein the fourth conversion formula is: Where Y i_tranij is the normalized contribution of the transformer reactance between nodes i and j to the self-admittance of node i; j is an imaginary unit; U Bi is the reference voltage at the transformer i end between nodes i and j; U ki is the tap voltage at transformer i between nodes i and j; X σij is the transformer leakage reactance converted by tapping on both sides. Then, the load contribution value Y of node i is i_load , Contribution value of compensation device Y i_shuntAnd the admittance value Y contributed by the line connected to node i i_lineij And the admittance value Y contributed by the transformer i_tranij Using the calculation formula Y i =Y i_load +Y i_shunt +ΣY i_lineij +ΣY i_tranij Add them together to get the total self-admittance value of node i, which is the first self-admittance matrix Y tt Then, the line connecting the elimination node i and the elimination node j is converted into the mutual admittance value between the nodes i and j using the fifth conversion formula, where the fifth conversion formula is: Where Y ij and Y ji is the impedance of the line between nodes i and j; is the mutual admittance introduced between nodes i and j; j is the imaginary unit; r ij and x ij are the per-unit values ​​of the resistance and reactance of the line between nodes i and j, respectively; and are converted into the mutual admittance value between nodes i and j using the sixth conversion formula using the transformer connected between the elimination node i and the elimination node j, where the sixth conversion formula is: Where Y ij and Y ji is the leakage reactance of the transformer between nodes i and j; is the mutual admittance introduced between nodes i and j; j is the imaginary unit; U Bi and U Bj is the reference voltage across the transformer between nodes i and j; U ki and U kj is the tap voltage; X σij is the transformer leakage reactance converted by the taps on both sides. Finally, create a square matrix with the same dimension as the number of elimination nodes, and fill the total self-admittance value of each elimination node and the mutual admittance value between the elimination nodes into the corresponding position to form the first self-admittance matrix Y tt .

[0107] The second determining subunit is configured to determine line parameters and transformer parameters of the elimination node set and the boundary node set based on the data file information, determine a mutual admittance matrix between the elimination node set and the boundary node set based on resistance and reactance, and determine a second self-admittance matrix of the boundary node set based on the line parameters and the transformer parameters, wherein the line parameters include the resistance and the reactance;

[0108] It should be noted that the transformer parameters include the transformer leakage reactance, the reference voltage at both ends of the transformer, and the tap voltage at both ends of the transformer;

[0109] In some embodiments, the connection between nodes, line parameters (resistance, reactance, admittance to ground, etc.), and transformer parameters (leakage reactance, two-terminal reference voltage, two-terminal tap voltage), etc. in the power grid data file are read by professional power grid analysis software or self-defined analysis program, then according to the graph model of the power grid and the node screening result, the connection lines or transformers between the node set and the boundary node set are explicitly eliminated, and the resistance r ij , reactance x ij , and line parameter y ij_i of these connection lines or transformers are determined. ij_j ; then, according to the resistance r ij and reactance x ij of the line, the mutual admittance Y ij and Y ji between the boundary node i and the eliminated node j are calculated by using the third conversion formula. Bi ; thereafter, according to the two-terminal reference voltage U Bj and U ki , tap voltage U kj and U σij , and transformer leakage reactance X ij converted according to the tap on both sides between the nodes i and j of the transformer, the mutual admittance Y ji and Y ij between the boundary node i and the eliminated node j are calculated by using the fourth conversion formula. ji ; then, the calculated mutual admittance Y et and Y te are filled in the corresponding positions of the matrix to obtain the mutual admittance matrix Y i and Y i_lineij ; subsequently, the line and transformer between the boundary node and the eliminated node are used to calculate the self-admittance of the boundary node, and for the boundary node i, the self-admittance calculation formula is Y i_tranij , wherein Y i_lineij is the contribution value of the line between the boundary node i and the eliminated node j to the self-admittance of the boundary node i after unitization, which is calculated by using the fifth conversion formula; Y i_tranij is the contribution value of the transformer between the boundary node i and the eliminated node j to the self-admittance of the boundary node i after unitization, which is calculated by using the sixth conversion formula; finally, the calculated self-admittance Y i of the boundary node is filled in the corresponding position of the matrix to obtain the second self-admittance matrix Y ee , i.e., the boundary node self-admittance matrix.

[0110] It should be noted that generally nodes are not connected by lines or transformers at the same time, so the contribution of the line / transformer to the mutual admittance between nodes i and j is not expressed in components. The result of the mutual admittance calculation of the line / transformer between nodes i and j, Y ij 、Y ji It can be used as the mutual admittance between nodes i and j. The mutual admittance between nodes i and j can be determined based on the conversion calculation formula from the line model to the admittance matrix model and the conversion formula from the transformer model to the admittance matrix model.

[0111] It should be noted that for the admittance matrix of the boundary node, since ① the admittance to ground converted from the boundary node's own load, line high impedance, reactive / active compensation, etc.; ② the mutual admittance between the boundary nodes; ③ the electrical equipment / line represented by the mutual admittance between the boundary node and the retained node still retains these admittance parameters after kron simplification, it is not necessary to model the admittance matrix of these components in this link. The mutual admittance between the boundary node and the eliminated node is simplified to the equivalent system after kron simplification. When constructing the admittance matrix, only the mutual admittance between the boundary node and the node to be eliminated is modeled to obtain the mutual admittance matrix Y between the node to be eliminated and the boundary node. et and Y te .

[0112] The third determining subunit is configured to determine a corresponding node admittance matrix based on the first self-admittance matrix, the mutual admittance matrix, and the second self-admittance matrix.

[0113] In some embodiments, based on the first self-admittance matrix Y tt , the mutual admittance matrix Y et and Y te , and the second self-admittance matrix Y ee , determine the corresponding node admittance matrix Where Y tt The admittance matrix of the node to be eliminated, which is composed of the self-admittance of the node to be eliminated and the mutual admittance between the eliminated nodes, is also the first self-admittance matrix. et and Y te are the mutual admittance matrices of the node to be eliminated and the boundary node composed of the line or transformer between the node to be eliminated and the boundary node; Y ee The self-admittance of the boundary node contributed by the line and transformer between the boundary node and the node to be eliminated is also the second self-admittance matrix, which is a diagonal matrix; U t 、U e are column vectors consisting of the voltages of the elimination nodes and boundary nodes, respectively.

[0114] In some embodiments, the self-admittance terms in the first self-admittance matrix, the mutual-admittance terms in the mutual-admittance matrix, and the self-admittance terms in the second self-admittance matrix are added to the corresponding positions of the node admittance matrix according to the order of the nodes. In this way, a node admittance matrix containing all node self-admittance and mutual-admittance information can be obtained. The expression of the node admittance matrix Y is: Where Y tt is the first self-admittance matrix of the node to be eliminated, which is composed of the self-admittance of the node to be eliminated and the mutual admittance between the eliminated nodes; Y et 、Y te is the mutual admittance matrix between the node to be eliminated and the boundary node, which is composed of the line or transformer between the node to be eliminated and the boundary node; Y ee is the second self-admittance matrix of the boundary node contributed by the line and transformer between the boundary node and the node to be eliminated, which is a diagonal node; U t 、U e are column vectors consisting of the voltages of the elimination nodes and boundary nodes, respectively.

[0115] By converting these parameters into the form of mutual admittance matrices and self-admittance matrices, the complex electrical connection relationship of the power grid can be clearly presented. By integrating the information of the three matrices, a complete and concise mathematical model can be constructed to represent the complex power grid system, so that subsequent power grid analysis and calculations can be carried out in a more concise and efficient mathematical framework, thereby greatly improving the efficiency of analysis and calculation.

[0116] In some embodiments, the simplification element 2003 includes a simplification subunit and a fourth determination subunit, specifically: the simplification subunit is used to process the node admittance matrix by the Kron simplification method to obtain a simplified matrix; the fourth determination subunit is used to convert the simplified matrix into the electrical parameters of the boundary node set and determine the target topology model based on the boundary parameters. Specifically: first, apply Y eq =Y ee -Y et (Y tt ) -1 Y te The Kron simplification of the admittance matrix of the simplified system, the simplified network equation is: 0 = Y eq U e , where Y eq U is the additional system admittance matrix of the simplified boundary nodes; e is a column vector of voltages at the boundary nodes; then, the Y eq The off-diagonal elements of the matrix (Y eq ) ijConvert it into line and transformer impedance between boundary nodes i and j. If there is a line / transformer connection between the two nodes, connect the new line in parallel with the original transformer / line to Generate additional ground admittance Y for boundary node i i , then apply Where, P ishunt , Q ishunt is the original active power and reactive power load of boundary node i, S B is the base capacity, V i is the voltage amplitude of node i, P ishunt_new , Q ishunt_new To compensate for the active power and reactive power of the equivalent system boundary node i, other parameters of the boundary node remain unchanged to maintain its original electrical characteristics; the additional ground admittance is used to generate new boundary node reactive and active power compensation, thus obtaining the simplified target topology model.

[0117] It should be noted that after obtaining the target topology model, it needs to be filled into the equivalent system power grid data file. Taking the BPA dat file as an example, it uses text to save the names and corresponding parameters of each node, each line, and transformer. Each line represents a node or a line, a transformer, and simulation control statements are set at the beginning and end of the document. Create a new equivalent system power grid data dat file, and first copy the simulation control statements of the original power grid data dat file to the equivalent system dat file. Then traverse the node, line, and transformer rows of the original power grid data dat file in turn. For the node row visited, if the node to which the node row belongs is a node in inner_buses, then copy the row directly to the equivalent system power grid data dat file; if the node to which the node row belongs is a node in edge_buses, then read the text of the node row and modify the power compensation parameter of the row to P ishunt_new , Q ishunt_new , the rest of the parameters remain unchanged and are filled into the equivalent system power grid data dat file; if the node to which the node row belongs is a node in throw_buses, the row is not copied. For the accessed line and transformer row, if the two nodes connected to the line and transformer are not nodes in throw_buses, the row is directly copied to the equivalent system power grid data dat file, otherwise it is not copied. eq The mutual admittance between nodes formed by non-diagonal elements (Y eq ) ij If the voltage levels of the two nodes are equal, a new line is created and (Y eq ) ij Use r ij +jx ij =-1 / (Y eq )ij Convert it into impedance and fill it into the row, then fill it into the equivalent system grid data dat file; if the voltage levels of the two nodes are not equal, create a new transformer row and change (Y eq ) ij Use r ij +jx ij =-1 / (Y eq ) ij Convert it into impedance and fill it into the new row, set the transformer tap voltage to the voltage corresponding to the voltage level of the two nodes, and then fill the row into the equivalent system power grid data dat file.

[0118] Please refer to Figure 4 , Figure 4 : is a schematic diagram comparing the traditional method provided by this application and the simplified result of this application, wherein: Figure 4 (a) is the simplified result of the traditional method without node screening. Figure 4 b) is the simplified result after node screening by this application.

[0119] By simplifying in this way, the complex electrical connection relationship of the power grid can be simplified and expressed in matrix form, eliminating redundant electrical parameters and connection information, further reducing the complexity of the power grid topology model at the electrical parameter level, making the mathematical model of the power grid more concise and clear, and thus able to be more efficiently used for various analysis and calculations of the power grid, providing a simpler and more effective model basis for subsequent power grid analysis and precise control.

[0120] The embodiment of the present invention constructs a topology model by reading the power system data file, which can clearly present the overall structure and connection relationship of the power grid; by determining the initial retained node set, a basic framework can be set for the subsequent simplification process, ensuring that the simplified model can retain the most important parts of the power grid; by removing the node set to be filtered and the corresponding associated edges from the copy of the topology model, the number of nodes and connection relationships in the topology model are directly reduced, and the obtained subgraphs and subsequent hierarchical screening based on the first number of nodes can further remove relatively minor parts of the power grid topology analysis and understanding, retain key nodes and connection relationships, thereby effectively reducing the complexity of the power grid topology model; after generating a node admittance matrix based on eliminating the node set and electrical relationship, it is simplified, and the complex power grid electrical connection relationship can be simplified and expressed in matrix form, removing redundant electrical parameters and connection information, further reducing the complexity of the power grid topology model at the electrical parameter level, making the mathematical model of the power grid more concise and clear, and thus can be more efficiently used for various analysis and calculations of the power grid, providing a simpler and more effective model foundation for subsequent power grid analysis and precise control. Compared with the existing technology, this application can reduce the complexity of the power grid topology model and meet the needs of efficient analysis and precise control.

[0121] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. Furthermore, in the drawings of the device embodiments provided by the present invention, the connection relationship between modules indicates that they have a communication connection, which may be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement the present invention without inventive effort.

[0122] like Figure 5 As shown, based on the above-mentioned device embodiment, a corresponding method embodiment is provided;

[0123] An embodiment of the present invention provides a method for simplifying the topology of a power system, comprising steps S501 to S503;

[0124] Step S501: constructing a topology model according to the data file information input by the user, and determining an initial reserved node set of the topology model;

[0125] Step S502: determining a set of nodes to be filtered according to the node characteristics of each node in the topological structure model, and removing the set of nodes to be filtered and the corresponding associated edges from the copy of the topological structure model to obtain several subgraphs, determining a corresponding first augmented subgraph based on each of the subgraphs, performing hierarchical screening on each of the first augmented subgraphs based on the first number of nodes to obtain a screening result, and determining a target retained node set based on the screening result and the initial retained node set, and determining an eliminated node set and a boundary node set based on the target retained node set, wherein the first number of nodes is the number of retained nodes having connecting edges between each of the first augmented subgraphs and the initial retained node set;

[0126] Step S503 , generating a node admittance matrix based on the eliminated node set and the electrical relationship, simplifying the node admittance matrix, and outputting a simplified target topology structure model, wherein the electrical relationship is the electrical connection relationship between the eliminated node set and the boundary node set.

[0127] It can be understood that the above-mentioned method embodiment corresponds to the device embodiment of the present invention, and its specific steps correspond to the device item, so they are not repeated here.

[0128] Based on the above-mentioned embodiment of the method for simplifying the topology structure of the power system, another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the method for simplifying the topology structure of the power system of any embodiment of the present invention is implemented.

[0129] For example, in this embodiment, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to implement the present invention. The one or more module elements may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0130] The terminal device may be a computing device such as a desktop computer, a notebook computer, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0131] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, connecting various parts of the entire terminal device using various interfaces and lines.

[0132] Based on the above-mentioned method embodiments, another embodiment of the present invention provides a computer-readable storage medium, including a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the topology structure simplification method of the power system described in any one of the above-mentioned method embodiments of the present invention.

[0133] Wherein, the module / unit integrated in the device / terminal equipment, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0134] The above is 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 principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A system for simplifying the topology of a power system, characterized in that: include: Input module and simplified module; The input module is used for allowing the user to input data file information of the power system and transmit the data file information to the simplification module; The simplification module includes: a first determination unit, a second determination unit and a simplification element; The first determining unit is configured to construct a topology structure model according to the data file information and determine an initial reserved node set of the topology structure model; The second determination unit is used to determine a set of nodes to be filtered according to the node characteristics of each node in the topological structure model, and remove the set of nodes to be filtered and the corresponding associated edges from the copy of the topological structure model to obtain several subgraphs, determine a corresponding first augmented subgraph based on each of the subgraphs, perform hierarchical screening on each of the first augmented subgraphs based on the first number of nodes to obtain a screening result, and determine a target retained node set based on the screening result and the initial retained node set, and determine an eliminated node set and a boundary node set based on the target retained node set, wherein the first number of nodes is the number of retained nodes that have connecting edges between each of the first augmented subgraphs and the initial retained node set; The simplification element is used to generate a node admittance matrix based on the eliminated node set and the electrical relationship, and simplify the node admittance matrix to output the simplified target topology structure model, wherein the electrical relationship is the electrical connection relationship between the eliminated node set and the boundary node set.

2. The topology simplification system of the power system according to claim 1, characterized in that: The second determining unit includes a calculating subunit and a processing subunit: The calculation subunit is configured to calculate the out-of-line degree and the second node number of each node in the topological structure model, wherein the node characteristics include the out-of-line degree and the second node number, and the second node number is the number of retained nodes having connecting edges with the initial retained node set; The processing sub-unit is used to add the node to the set of nodes to be screened if the out-of-line degree corresponding to each node is greater than a first preset threshold and the second number of nodes is greater than a second preset threshold, until all nodes in the topological structure model are processed and the set of nodes to be screened is determined.

3. The topology simplification system of the power system according to claim 1, characterized in that: The second determining unit further includes: a first searching subunit, a second searching subunit and an adding subunit: The first search sub-unit is configured to traverse the nodes in each of the subgraphs and search the topology model for associated nodes in the initial retained node set connected to each of the subgraph nodes to determine an associated node set; The second search subunit is used to search for the associated edges between the associated node set and each subgraph node in the topological structure model to obtain an associated edge set; The adding sub-unit is used to add the associated node set and the associated edge set to the corresponding subgraph to obtain the corresponding first augmented subgraph.

4. The topology simplification system of the power system according to claim 1, characterized in that: The second determining unit further includes: a traversal subunit and a screening subunit, specifically: The traversal sub-unit is used to determine the number of first nodes in each of the first augmented subgraphs that belong to the initial retained node set and have connecting edges with other nodes in the corresponding first augmented subgraph; The screening sub-unit is configured to, if the first number of nodes is less than a third preset threshold, traverse all nodes in each of the first augmented subgraphs and determine whether there are breakpoints in the first augmented subgraph; if so, remove all breakpoints and corresponding associated edges in a copy of the first augmented subgraph to obtain a plurality of second augmented subgraphs; and count the third number of nodes in the initial retained node set contained in each of the second augmented subgraphs; if the third number of nodes meets a preset condition, remove the corresponding node from each of the second augmented subgraphs, until no new breakpoints are generated in each of the second augmented subgraphs or all nodes are traversed, thereby obtaining a plurality of screening results.

5. The topology simplification system of the power system according to claim 4, characterized in that: The screening subunit is specifically: If the third number of nodes is 0, remove all nodes in the second augmented subgraph; If the third number of nodes is 1, all nodes except the retained nodes and the corresponding associated edges in the second augmented subgraph are removed, and new retained associated edges are constructed between the retained nodes.

6. The topology simplification system of the power system according to claim 1, characterized in that: The simplification element includes a first determining subunit, a second determining subunit and a third determining subunit: The first determining subunit is configured to determine electrical parameters of each node in the elimination node set based on the data file information, and construct a corresponding first auto-admittance matrix based on the electrical parameters, wherein the electrical parameters include load and power compensation device; The second determining subunit is configured to determine line parameters and transformer parameters of the elimination node set and the boundary node set based on the data file information, determine a mutual admittance matrix between the elimination node set and the boundary node set based on resistance and reactance, and determine a second self-admittance matrix of the boundary node set based on the line parameters and the transformer parameters, wherein the line parameters include the resistance and the reactance; The third determining subunit is configured to determine a corresponding node admittance matrix based on the first self-admittance matrix, the mutual admittance matrix, and the second self-admittance matrix.

7. The topology simplification system of the power system according to claim 1, characterized in that: The simplification element includes a simplification subunit and a fourth determination subunit, specifically: The simplification subunit is used to process the node admittance matrix by using the Kron simplification method to obtain a simplified matrix; The fourth determining subunit is configured to convert the simplified matrix into electrical parameters of the boundary node set, and determine a target topology structure model based on the boundary parameters.

8. A method for simplifying the topology of a power system, characterized in that: include: Constructing a topology structure model according to the data file information input by the user, and determining an initial reserved node set of the topology structure model; Determine a set of nodes to be filtered according to the node characteristics of each node in the topological structure model, remove the set of nodes to be filtered and the corresponding associated edges from the copy of the topological structure model to obtain several subgraphs, determine a corresponding first augmented subgraph based on each of the subgraphs, perform hierarchical screening on each of the first augmented subgraphs based on a first number of nodes to obtain a screening result, determine a target retained node set based on the screening result and the initial retained node set, determine an eliminated node set and a boundary node set based on the target retained node set, wherein the first number of nodes is the number of retained nodes having connecting edges between each of the first augmented subgraphs and the initial retained node set; A node admittance matrix is ​​generated based on the eliminated node set and the electrical relationship, and the node admittance matrix is ​​simplified to output a simplified target topology structure model, wherein the electrical relationship is an electrical connection relationship between the eliminated node set and the boundary node set.

9. A terminal device, characterized in that: include: one or more processors; a memory, coupled to the processor, for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for simplifying the topology of a power system as claimed in claim 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for simplifying the topology of a power system according to claim 8 is implemented.

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