A heterogeneous network topology mapping method for off-line and on-line grid data

Abstract

The application discloses a heterogeneous network topology mapping method for power grid offline and online data, and has the characteristics that: according to the electrical characteristics of primary equipment of a power grid and inherent characteristics of the power grid, the primary equipment topology network of the power grid is decomposed into two-level networks; the first-level network is composed of power stations and lines, and forms a power station-level topology network; the topology network is homologous and isomorphic, and a subnet isomorphic algorithm of graph theory is applied to topology mapping; the second-level network is composed of primary equipment of each power station, and offline data and online data form topology networks according to the connection relationship between the primary equipment and the primary equipment; the first-level network and the second-level network expand the topology network of the power stations and the lines of the first-level network to the topology network of the primary equipment through the connection relationship of busbars and lines, realize the whole-network topology mapping of the offline and online data, and realize the primary equipment "node corresponding" mapping of the offline data and the online data to the whole-network "topology network" mapping.

Description

Technical Field

[0001] The present application relates to the technical field of power system simulation, and in particular to a method for mapping heterogeneous grid topology of offline and online power grid data. Background Art

[0002] At present, there are roughly two modes for power grid simulation analysis in China, offline and online. The offline mode usually uses BPA and PSASP power calculation and analysis programs to simulate and analyze pre-built power grid models. This patent uses the offline data model of the power grid calculation database (PSDB) to support the export of power grid mathematical models for different types of calculation programs. One is based on online data, such as the QS file of the D5000 operating status estimation, combined with the offline power grid data to perform model mapping and other steps to generate a set of calculation models that conform to the power grid operating conditions, and then use the BPA or PSASP software mentioned above to perform various flow, stability and other analysis calculations.

[0003] Currently, offline and online data mapping primarily involves mapping the operating information of primary devices (excluding busbars) in online data to the corresponding devices in offline data. This information is then combined with the offline network topology for grid analysis, approximating the actual operating conditions of the online grid. However, precise network topology mapping, which requires a one-to-one correspondence between primary devices (including busbars) and the connections between them, has not yet been achieved. Summary of the Invention

[0004] The present application provides a heterogeneous grid topology mapping method for offline and online data of a power grid, which realizes the mapping of the "node correspondence" of primary equipment of offline data and online data to the "topology network" of the entire power grid.

[0005] The present application provides a heterogeneous grid topology mapping method for offline and online data of a power grid, characterized by comprising:

[0006] According to the electrical characteristics of the primary equipment of the power grid and the inherent characteristics of the power grid, the primary equipment topology network of the power grid is decomposed into a two-level network;

[0007] The first layer of the network consists of plants and lines, forming a plant-level topological network; the topological network is homologous and isomorphic, and the subnet isomorphism algorithm of graph theory is used for topological mapping;

[0008] The second layer of the network consists of the primary equipment of each plant and station. Offline data and online data form a topological network based on the connection relationship between primary equipment.

[0009] Through the connection relationship between busbars and lines, the first-layer network and the second-layer network expand the topological network of the plant station and line of the first-layer network to the topological network of the primary equipment, realizing the topological mapping of the entire network of offline and online data.

[0010] Preferably, the two-level network, the first layer network and the second layer network contain and are interconnected with each other, and can be independently topologically analyzed.

[0011] Preferably, the primary equipment of the power grid includes: a generator, a transformer, a capacitor, and a reactor.

[0012] Preferably, the second layer network further includes:

[0013] While forming the topological network, the bus sets of the online system and the offline system and the primary device sets connected to the same bus node are also formed.

[0014] Preferably, the method provided by the present application further comprises:

[0015] The primary device connection relationship of the topology network of the online system and the offline system is consistent, and the connection status of the primary device and the bus node is set to achieve consistency in the topology network of the equipment within the station.

[0016] This application provides a heterogeneous grid topology mapping method for offline and online data in a power grid. Based on graph theory and the electrical characteristics of the grid and primary equipment, the power grid is abstracted into a two-layer topology. A complex undirected, cyclic primary equipment network is decomposed into two layers, simplifying the power grid topology model. The topology analysis is performed layer by layer based on the characteristics of each network layer, improving the efficiency of topology analysis. The second-layer in-station equipment subnet is based on the connection relationship between the primary equipment network and the bus node, combined with set operations, to achieve the mapping of the primary equipment "node correspondence" of offline data and online data to the "topology network" of the entire network. This allows the offline operation mode to be formed from the online operation state of the power grid, the primary equipment status to be set, and the topology of the two systems to be consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a heterogeneous grid topology mapping method for offline and online data of a power grid provided by an embodiment of the present application;

[0018] Figure 2 A portion of the power grid topology network involved in the embodiments of the present application (primary devices are nodes);

[0019] Figure 3 It is a part of the power grid topology network involved in the embodiments of the present application (primary equipment is a node, distinguishing between plants and stations);

[0020] Figure 4 It is a part of the power grid topology network involved in the embodiment of the present application (the plant station is a node);

[0021] Figure 5 This is a primary wiring diagram of a double busbar in a certain plant station involved in an embodiment of the present application;

[0022] Figure 6 This is a simplified primary wiring diagram within a PSDB or D5000 station involved in the embodiments of the present application;

[0023] Figure 7 The embodiment of this application involves Figure 6-1 Main wiring topology and busbar node set, equipment set;

[0024] Figure 8 The embodiment of this application involves Figure 6-4 Main wiring topology and busbar node set, equipment set;

[0025] Figure 9 The embodiment of this application involves Figure 6-3 Main wiring topology and busbar node set, equipment set;

[0026] Figure 10 It is the conversion of the simplified primary wiring diagram within the station involved in the embodiment of the present application;

[0027] Figure 11 It is the mapping of the PSDB bus node to the D5000 bus node involved in the embodiment of the present application;

[0028] Figure 12 This is the D5000 and PSDB system site topology network mapping process involved in the embodiments of the present application;

[0029] Figure 13 The embodiment of this application involves Figure 6-4 arrive Figure 6-1 The correspondence between the primary device set. DETAILED DESCRIPTION

[0030] The following description sets forth many specific details to facilitate a thorough understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the scope of the present application. Therefore, the present application is not limited to the specific implementations disclosed below.

[0031] Please see Figure 1 , Figure 1 This is a flow chart of a heterogeneous grid topology mapping method for offline and online data of a power grid provided by an embodiment of the present application. Figure 1 The method provided in the embodiments of the present application is described in detail.

[0032] Step S101 : Decomposing the primary equipment topology network of the power grid into two-level networks according to the electrical characteristics of the primary equipment of the power grid and inherent characteristics of the power grid.

[0033] This patent is based on two typical offline and online systems, PSDB and D5000, to analyze the topological mapping of the power grid. Both have built mathematical models of the power grid, but with different focuses and data structures. PSDB focuses on the full life cycle maintenance of primary equipment, as well as the splicing of power grid areas above it, and the management and simulation analysis and calculation of power grid operation mode in a certain period of time. In the description of primary equipment, the switchgear and busbars are simplified, knife switches, circuit breakers, etc. are abstracted into switch lines, and busbars are merged and abstracted into nodes. In the description of the operating status of the equipment, the description of the power grid operating conditions is achieved by splitting the nodes and opening and closing the switch lines. The D5000 system measures the operating status of the primary equipment of the entire power grid, including the commissioning status of the primary equipment and nodes with zero electrical distance.

[0034] According to the description of nodes and connecting lines in graph theory, PSDB and D5000 are homogeneous heterogeneous descriptions of the same power grid, such as Figure 2 As shown, although Figure 2-1 、 Figure 2-2 、 Figure 2-3 、 Figure 2-4 Each describes a portion of the electrical network of a power grid, but the resulting topologies can be diverse. If the grid topology is not considered, primary devices (except busbar nodes) can be mapped one-to-one, meaning node-to-node. However, nodes in the D5000 are dynamic, constantly changing based on the status of switchgear such as circuit breakers. Therefore, they cannot be directly mapped to PSDB nodes. The connection relationships between devices and nodes cannot be mapped either, making it impossible to directly implement the network mapping in graph theory, which involves a one-to-one mapping of nodes and edges.

[0035] In graph theory, the topological mapping problem between two networks is also known as graph isomorphism. This involves a one-to-one correspondence between nodes and edges, or a network being a subnetwork of another. For the primary device topology network formed by the power grid, where devices are nodes and connections are edges, forming a graph, graph isomorphism algorithms are applicable. However, the offline PSDB model and the online D5000 model differ in their descriptions of power grid device models, resulting in different topological networks. Therefore, graph isomorphism algorithms cannot be directly applied for mapping.

[0036] Step S102: The first layer of the network is composed of plants and lines, forming a topological network at the plant level; the topological network is homologous and isomorphic, and a subnet isomorphism algorithm of graph theory is applied for topological mapping.

[0037] The present invention is to decompose the primary equipment topology network of the entire network into two levels of networks based on the electrical characteristics of the primary equipment of the power grid and the inherent characteristics of the power grid, namely: one level for the plant station and the line, and one level for the primary equipment in the station. The layers are mutually inclusive and interconnected, and can be independently topologically analyzed.

[0038] The first layer of network consists of plants and lines. PSDB and D5000 systems have descriptions of plants, lines, and the connection relationship between plants, lines, and can directly form a plant-level topology network, such as Figure 3 , Figure 4 This level of network is homologous and isomorphic, and the subnet isomorphism algorithm of graph theory can be directly applied for topological mapping.

[0039] Step S103: The second layer network is composed of the primary equipment of each plant station, and the offline data and the online data form a topological network according to the connection relationship between the primary equipment and the primary equipment.

[0040] The second-layer network consists of the primary equipment of each plant and station. Both offline and online data can abstract the topological network of bus nodes, generators, transformers, capacitors and reactors and the connection relationship between primary equipment, but the description of bus nodes is different. The PSDB's station topology description can be considered a simplification of the real power grid primary wiring diagram. The switching equipment (switches, circuit breakers, etc.) is abstracted as switch lines, and the bus lines are drawn into bus nodes. It is static, created once, and will not change in the future. In the D5000 measurement data, the bus nodes are drawn to the nodes with zero electrical power based on the status of the switches and circuit breakers, and are dynamic. The node description at each moment may be different.

[0041] In step S104, the first layer network and the second layer network extend the topology network of the plant and line of the first layer network to the topology network of the primary equipment through the connection relationship between the bus and the line, thereby realizing the topology mapping of the entire network of offline and online data.

[0042] Figure 5 The primary wiring diagram of a station is shown. The main wiring mode is double busbar operation. According to the operation status of the station, many primary equipment operation modes can be derived, such as Figure 6 In D5000, the primary wiring diagram in the station is the simplest wiring method with zero electrical distance, which is abstracted based on the commissioning status of the switchgear. Figure 6-3 , Figure 6-4 , dynamic changes. In the PSDB system, users can simplify the switchgear and busbars according to certain principles. Figure 6-1 , Figure 6-2 , Figure 6-3 All possible. Figure 6-4 It is possible, but not recommended, as it limits the flexibility of the main wiring and may cause topology mapping failure.

[0043] Although the busbar nodes of the D5000 system are dynamic and the connection relationship between the primary equipment and the busbar nodes is also dynamic, the combinations are finite. This is because after the main wiring mode of the plant is determined, the combination of the commissioning status of the switchgear has certain rules and is finite. The description of the busbar nodes and the switch lines in the station in the PSDB system is also based on the commonly used operation mode of the plant, which is reasonably simplified to reduce the flexibility of the busbar wiring method, but increase readability, and is also finite. Both abstract the busbar node set and the set of primary equipment connected to the busbar node, such as Figure 7 , Figure 8 , Figure 9 ,The topology mapping problem within the two system stations can be transformed into the ,intersection and union problem of sets.

[0044] The PSDB station primary wiring diagram can be understood as a transitional state between the real primary wiring diagram and the D5000 electrical zero simplified primary wiring diagram, which is static. By splitting the busbar node and setting the switch line status, it can be transformed into the D5000 dynamic simplified station primary wiring diagram, changing from static to dynamic. In other words, the busbar splitting corresponds to the division of a certain busbar node device set into multiple subsets, setting the station line to be effective, and finding the union of the two node device sets. Figure 10 As shown, theoretically, every PSDB static topology network can be mapped to the D5000 dynamic topology network.

[0045] The above method is based on the reasonable simplification of the main wiring mode in the station by the PSDB system. If it is unreasonable, such as Figure 6-2 If there is no switch line between busbar nodes, then the devices based on b11 and b12 cannot operate together, that is, the set union cannot be converted to Figure 6-3 This operating state.

[0046] Through the above method, the first-layer network and the second-layer network are connected through the bus and line, and the topological network of the first-layer network's plant station and line is expanded to the topological network of the primary equipment, realizing the topological mapping of the entire network of offline and online data.

[0047] The best embodiments of the present invention are as follows:

[0048] For the first-tier network, which consists of plant and station lines, the topology is homogeneous and can be directly mapped. Mature graph isomorphism algorithms exist, such as the Ullmann algorithm, the Nauty algorithm, the SD algorithm, and the VF algorithm. The specific formulas and steps are not repeated in this invention.

[0049] For the second-layer network, based on the topological mapping of the plant-station line level, the two systems simplify the primary equipment topology of each plant-station, and form a simplified topological network based on the outgoing line end, generator end or PSDB station switch line, and form their own bus node set and the primary equipment set connected to the same bus node, such as Figure 7 , Figure 8 , Figure 9 shown.

[0050] In D5000, the electrical distance of all nodes in the primary wiring diagram of the station is zero, which can only be Figure 6-3 , Figure 6-4 , is dynamic. However, in the PSDB system, reasonable simplification of switchgear and busbar may be Figure 6-1 , Figure 6-2 , Figure 6-3 , is static. The PSDB system can simulate the D5000 station topology by splitting the busbar and setting the switch line status. That is, the intersection of the equipment set (outlet end, transformer end) is calculated to achieve the consistency of the primary equipment connection relationship of the two topology networks, and then set the primary equipment and busbar node connection status to achieve the consistency of the station equipment topology network, such as Figure 11 As shown in Figure 1, the problem of device topology mapping within a station is converted into a process of finding the intersection and union of device sets.

[0051] Figure 6-3 Use sets to express the sets of devices belonging to different nodes S31 = {11, 12, T1} and S32 = {13, 14, 15, T2}, Figure 6-4 Use the set to express the set of devices belonging to different nodes S4 = {11, 12, 13, 14, 15, T1, T2}. Assume that the D5000 system Figure 6-3 Mapping to PSDB system Figure 6-4 ,The two network topology mapping problems can be transformed into the ,intersection and union problem of solving sets S31, S32 and S4. Since S4 = S31 ∪ S32, the bus of the PSDB ,system needs to be split into two bus segments containing devices {11, 12, T1} and {13, 14, 15, T2}. The denominator runs to achieve the topology consistency of the ,two systems.

[0052] If it is a complex mapping relationship, such as the D5000 system Figure 6-4 Mapping to PSDB system Figure 6-1 , Figure 6-4 The device set is expressed as: S41 = {11, 12, T1} and S42 = {13, 14, 15, T2}. Figure 6-1 The devices are expressed as a set S11 = {11, 12}, S12 = {13, 14}, S13 = {15, T1, T2}, because: S13=(S13∩S41)∪(S13∩S42), such as Figure 13 So: Figure 6-1 The bus node b3 is split into two bus nodes b31 and b32, that is, two subsets S131 = {T1} and S132 = {15, T2}. The b1-b2 switch line is disconnected, the b1-b3 switch line is valid, b1 and b31 operate together as a bus, the b2-b3 switch line is valid, b2 and b32 operate together as a bus, thereby achieving topological consistency between the two systems.

[0053] Through Figure 9 The first and second layers are connected through busbars and lines, thus expanding the first-layer plant and station line topology network to the primary equipment topology network, thus achieving the topology mapping of the entire network for offline and online data.

[0054] This paper proposes a method for mapping homogeneous and heterogeneous grid topologies for offline and online data. The core concepts are: 1) Based on graph theory and the electrical characteristics of the grid and primary equipment, the grid is abstracted into a two-layer topology. A complex, undirected, cyclic primary equipment network is decomposed into two layers, simplifying the grid topology model. This allows for layer-by-layer topological analysis based on the characteristics of each network layer, improving topological analysis efficiency. 2) For the second-layer in-station equipment subnet, the connection relationship between the primary equipment network and the busbar node is combined with set operations to map the primary equipment "node correspondence" of offline and online data to the entire network "topological network." This allows the PSDB operation mode to be formed from the online grid operation state, setting the primary equipment state while maintaining the topological consistency of the two systems.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art may still modify or make equivalent substitutions to the specific implementations of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the scope of protection of the claims of the present invention to be approved.

Claims

1. A heterogeneous grid topology mapping method for offline and online data of a power grid, characterized in that: include: According to the electrical characteristics of the primary equipment of the power grid and the inherent characteristics of the power grid, the primary equipment topology network of the power grid is decomposed into a two-level network; The first layer of the network consists of plants and lines, forming a plant-level topological network; the topological network is homologous and isomorphic, and the subnet isomorphism algorithm of graph theory is used for topological mapping; The second-layer network consists of the primary equipment at each plant and substation. Offline and online data form a topological network based on the connections between primary equipment. This topological network also forms busbar sets for the online and offline systems, as well as sets of primary equipment connected to the same busbar node. Through the connection between busbars and lines, the first-layer network and the second-layer network extend the topology network of the first-layer network's plant and line to the topology network of the primary equipment, realizing the topological mapping of the entire network between offline and online data. The primary device connection relationship of the topology network of the online system and the offline system is consistent, and the connection status of the primary device and the bus node is set to achieve consistency in the topology network of the equipment within the station.

2. The method according to claim 1, characterized in that The two-level network, the first layer network and the second layer network contain and connect to each other, and the first layer network and the second layer network can be independently topologically analyzed.

3. The method according to claim 1, characterized in that The primary equipment of the power grid includes: generators, transformers, capacitors, and reactors.

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