A power grid fragile line identification method, system, storage medium and computing device
By using a method based on power grid topology and power flow calculation, vulnerable lines in the power grid are identified. By utilizing equivalent networks and the Tarjan algorithm, the problem of slow identification speed in large-scale power grids is solved, enabling rapid identification of vulnerable lines and supporting power grid stability analysis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA SOUTHERN POWER GRID COMPANY
- Filing Date
- 2023-02-16
- Publication Date
- 2026-06-02
AI Technical Summary
Existing technologies, especially in large-scale power grids, suffer from slow identification speeds due to the large amount of computation required to identify vulnerable power lines, making it difficult to quickly identify potential network disconnection risks.
Based on the current power grid topology and power flow calculation results, the power grid bridges that cause network disconnection are identified, and the vulnerability of the anticipated N-1 disconnected lines is identified through the equivalent network. The Tarjan algorithm is used for power grid bridge search and equivalent network processing.
It improves the speed of identifying vulnerable lines in the power grid, provides technical support for topology adjustment of short-circuit current in the power grid, reduces computational complexity, and improves identification efficiency.
Smart Images
Figure CN116260144B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method, system, storage medium, and computing device for identifying vulnerable power grid lines, belonging to the field of power system automation technology. Background Technology
[0002] Identifying vulnerable lines in a power grid is crucial for preventing large-scale blackouts and system instability. Research on vulnerable line identification primarily focuses on two aspects: power system operating status and structural identification based on complex network theory. While power system operating status analysis considers the grid's own operating state and power flow transfer, it lacks sufficient analysis of the grid's inherent structure and component relationships. Therefore, structural identification based on complex network theory is currently the main approach. This method reflects branch importance from a topological perspective, using indicators such as electrical distance, power flow betweenness, and power betweenness to study the relevant characteristics of the network topology model. It can identify vulnerable lines in the system structure while fully utilizing the physical characteristics of the power grid. However, if the anticipated N-1 disconnection lines are considered, the computational load becomes excessive when the grid is large, leading to slow identification speed. Therefore, a method to improve identification speed is needed. Summary of the Invention
[0003] This invention provides a method, system, storage medium, and computing device for identifying vulnerable power grid lines, which solves the problems disclosed in the background art.
[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0005] A method for identifying vulnerable power grid lines includes:
[0006] Power flow calculations are performed based on data about the current operation of the power grid.
[0007] Based on the power grid topology and power flow calculation results, a power grid bridge search is performed, and the power grid bridge that causes the current power grid to be disconnected is identified as a vulnerable line in the current operating mode.
[0008] For each anticipated N-1 disconnection line, if the anticipated N-1 disconnection line is identified based on the current operating mode of the power grid vulnerable lines, it is necessary to identify the vulnerable lines of the power grid, obtain the equivalent network of the circuit loop where the anticipated N-1 disconnection line is located, and identify the vulnerable lines of the power grid for the anticipated N-1 disconnection line based on the equivalent network.
[0009] The rules for identifying the power bridges that cause the current power grid network to disconnect are as follows:
[0010] The total active load of the subnet is greater than or equal to the load threshold or the total active power generation is greater than or equal to the power generation threshold; where the subnet is the subnet formed after the grid bridge is disconnected.
[0011] Based on the current operating conditions, the identified vulnerable lines of the power grid, which are expected to require N-1 disconnection, need to undergo vulnerable line identification, including:
[0012] If the N-1 disconnected line is expected to be one of the multiple circuits, then the N-1 disconnected line does not need to be identified as a vulnerable line in the power grid.
[0013] If the N-1 disconnected line is a grid bridge and the N-1 disconnected line has been identified under the current operating mode, then the N-1 disconnected line does not need to be identified as a vulnerable grid line.
[0014] If the anticipated N-1 disconnection line is not one of the two scenarios mentioned above, then the anticipated N-1 disconnection line needs to be identified as a vulnerable line in the power grid.
[0015] Obtain the equivalent network of the circuit loop containing the anticipated N-1 disconnected circuit, including:
[0016] From the power grid network diagram under the current operating mode, obtain the circuit loop where the N-1 disconnected line is located;
[0017] Equivalent values are obtained by equating the power values of the circuit loops and updating the power values of the connection nodes based on the power values of the equivalent lines, thus obtaining an equivalent network containing only circuit loops.
[0018] Identification of vulnerable power grid lines based on the equivalent network for anticipated N-1 disconnection lines, including:
[0019] Perform a power grid bridge search on the equivalent network, traverse the searched power grid bridges, and if there is a power grid bridge that causes the equivalent network to be disconnected, then identify the expected N-1 disconnected lines as vulnerable lines of the power grid.
[0020] A system for identifying vulnerable power grid lines, comprising:
[0021] The power flow calculation module performs power flow calculations based on data on the current operating mode of the power grid.
[0022] The first identification module searches for power grid bridges based on the power grid topology and power flow calculation results, and identifies power grid bridges that cause the current power grid network to disconnect as vulnerable lines in the current operating mode.
[0023] The second identification module, for each anticipated N-1 disconnection line, if it is determined that the anticipated N-1 disconnection line needs to be identified as a vulnerable line under the current operating mode, obtains the equivalent network of the circuit loop where the anticipated N-1 disconnection line is located, and identifies the vulnerable line of the anticipated N-1 disconnection line based on the equivalent network.
[0024] In the first identification module, the rule for identifying the power grid bridge that causes the current power grid network to disconnect is as follows:
[0025] The total active load of the subnet is greater than or equal to the load threshold or the total active power generation is greater than or equal to the power generation threshold; where the subnet is the subnet formed after the grid bridge is disconnected.
[0026] In the second identification module, based on the current operating mode of the power grid vulnerable lines, it determines that the expected N-1 disconnection lines need to be identified as vulnerable lines, including:
[0027] If the N-1 disconnected line is expected to be one of the multiple circuits, then the N-1 disconnected line does not need to be identified as a vulnerable line in the power grid.
[0028] If the N-1 disconnected line is a grid bridge and the N-1 disconnected line has been identified under the current operating mode, then the N-1 disconnected line does not need to be identified as a vulnerable grid line.
[0029] If the anticipated N-1 disconnection line is not one of the two scenarios mentioned above, then the anticipated N-1 disconnection line needs to be identified as a vulnerable line in the power grid.
[0030] A computer-readable storage medium storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform a method for identifying vulnerable power grid lines.
[0031] A computing device includes one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for performing a method for identifying vulnerable power grid lines.
[0032] The beneficial effects achieved by this invention are as follows: Based on the topology and power flow calculation results of the current operating mode, this invention searches for vulnerable lines in the power grid that cause the current power grid to break up. After each of the expected N-1 lines is disconnected, it identifies whether the disconnected line is a vulnerable line in the power grid that causes the new network to break up based on the power grid loop in which the disconnected line is located. This effectively improves the speed of identifying vulnerable links in the power grid and provides technical support for the analysis of power grid short-circuit current topology adjustment and limitation strategies. Attached Figure Description
[0033] Figure 1 A flowchart for a method to identify vulnerable power grid lines. Detailed Implementation
[0034] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.
[0035] like Figure 1 As shown, a method for identifying vulnerable power grid lines includes the following steps:
[0036] Step 1: Perform power flow calculation based on the data of the current power grid operation mode.
[0037] Step 2: Based on the power grid topology and power flow calculation results, perform a power grid bridge search and identify the power grid bridges that cause the current power grid network to disconnect as vulnerable lines in the current operating mode.
[0038] Step 3: For each anticipated N-1 disconnection line, if the anticipated N-1 disconnection line is identified as a vulnerable line under the current operating mode, the vulnerable line identification of the network needs to be performed. Obtain the equivalent network of the circuit loop where the anticipated N-1 disconnection line is located, and perform the network vulnerability identification of the anticipated N-1 disconnection line based on the equivalent network.
[0039] The above method searches for vulnerable lines in the power grid that cause the current power grid to break up based on the power flow calculation results of the current operating mode. After each of the expected N-1 lines is disconnected, it identifies whether the disconnected line is a vulnerable line that causes the new network to break up based on the power grid loop in which the disconnected line is located. This effectively improves the speed of identifying vulnerable links in the power grid and provides technical support for the analysis of power grid short-circuit current topology adjustment and constraint strategies.
[0040] As an embodiment of the present invention, in step 1 above, the active and reactive power of nodes required for power flow calculation can be obtained based on the current power grid, as well as information such as bus nodes, branches, and topology of the current power grid, such as bus node name, node voltage level, point active load and its corresponding zone, and line loop number.
[0041] Based on the topology and power flow calculation results, the Tarjan algorithm can be used to search for the current power grid bridges; where a power grid bridge is a line whose number of connected components in the circuit diagram would increase if the line were deleted.
[0042] The searched power grid bridges are filtered to identify those causing the current power grid network to disconnect, and these bridges are designated as vulnerable lines in the current operating mode. The rules for identifying the power grid bridges causing the current power grid network disconnection can be as follows:
[0043] Total active load P of the subnet dsum Greater than or equal to the load threshold (default 40MW) or the total active power generation P gsum Greater than or equal to the power generation threshold (default value 20MW); where, the subnet is the subnet formed after the grid bridge is disconnected;
[0044]
[0045] In the formula, N is the number of nodes in the subnet, and P di Let P be the active power load of the i-th node in the subnet. gi Let be the active power generation of the i-th node in the subnet.
[0046] Further, for each line that is expected to be disconnected by N-1, based on the vulnerable lines of the power grid under the current operating mode, it is determined whether the line that is expected to be disconnected by N-1 needs to be identified as a vulnerable line of the power grid.
[0047] The specific identification process is as follows:
[0048] If the anticipated N-1 disconnected line is one of multiple circuits, then the disconnection of this line will not affect the topology of the power grid, and this line is not a vulnerable line in the power grid. In other words, the anticipated N-1 disconnected line does not need to be identified as a vulnerable line in the power grid. If the anticipated N-1 disconnected line is a power grid bridge and the anticipated N-1 disconnected line has already been identified under the current operating mode, then the anticipated N-1 disconnected line does not need to be identified as a vulnerable line in the power grid. If the anticipated N-1 disconnected line does not fall into either of the above two categories, then the anticipated N-1 disconnected line needs to be identified as a vulnerable line in the power grid.
[0049] For lines requiring identification of vulnerable power grid lines, the circuit loop containing the anticipated N-1 disconnected lines is obtained from the power grid network diagram under the current operating mode (i.e., the initial network diagram). Specifically, the Tarjan algorithm can be used to perform a depth-first search on the initial network diagram starting from a certain vertex. When labeling, a `visit` array is set to represent the order number of the nodes visited, and a `low` array is set to represent the minimum order number among all nodes connected to the node. The network topology formed by nodes whose minimum order number is the same as the minimum order number of the first and last bus nodes of the anticipated N-1 disconnected lines is the circuit loop containing the anticipated N-1 disconnected lines.
[0050] Equivalent power values are applied to the lines connecting the circuit loops. The power values at the connection nodes are then updated based on the equivalent power values of the lines, resulting in an equivalent network containing only the circuit loops. This network can be represented by the following formula:
[0051]
[0052] Among them, P d ′ i′Let be the updated active power load of the i′-th node in the equi-network. Let P be the initial active load of the i′-th node in the equi-network, M be the number of nodes in the equi-network connected to the i′-th node, and P be the active load of the i′-th node. d ′ j Let P be the active power load of the j-th node in the equipotential network. g ′ i′ Let be the updated active power generation of the i′-th node in the equivalence network. Let P be the initial active power generation of the i′-th node in the equivalence network. g ′ j Let be the active power generation of the j-th node in the equivalence network.
[0053] Remove the expected N-1 disconnected lines from the equivalent network graph to form the operating mode after the expected N-1 lines are disconnected. Then, use the Tarjan algorithm to search for power grid bridges in the equivalent network. Traverse the searched power grid bridges. If there is a power grid bridge that causes the equivalent network to be disconnected, the expected N-1 disconnected lines are identified as vulnerable lines in the power grid.
[0054] The above method enables rapid identification of vulnerable lines in the power grid and provides technical support for the analysis of power grid short-circuit current topology adjustment and limitation strategies.
[0055] Based on the same technical solution, this invention also discloses a software system for the above-mentioned method, a power grid vulnerable line identification system, comprising:
[0056] The power flow calculation module performs power flow calculations based on data on the current operating mode of the power grid.
[0057] The first identification module searches for power grid bridges based on the power grid topology and power flow calculation results, identifying power grid bridges that cause the current power grid network to disconnect as vulnerable lines in the current operating mode.
[0058] In the first identification module, the rule for identifying the grid bridge that causes the current power grid network to be disconnected is: the total active load of the subnet is greater than or equal to the load threshold or the total active power generation is greater than or equal to the power generation threshold; where the subnet is the subnet formed after the grid bridge is disconnected.
[0059] The second identification module, for each anticipated N-1 disconnection line, if it is determined that the anticipated N-1 disconnection line needs to be identified as a vulnerable line under the current operating mode, obtains the equivalent network of the circuit loop where the anticipated N-1 disconnection line is located, and identifies the vulnerable line of the anticipated N-1 disconnection line based on the equivalent network.
[0060] In the second identification module, based on the current operating mode of the power grid vulnerable lines, it determines that the expected N-1 disconnection lines need to be identified as vulnerable lines, including:
[0061] If the anticipated N-1 disconnected line is one of the multiple circuits, then the anticipated N-1 disconnected line does not need to be identified as a vulnerable line in the power grid; if the anticipated N-1 disconnected line is a power grid bridge and the anticipated N-1 disconnected line has already been identified under the current operating mode, then the anticipated N-1 disconnected line does not need to be identified as a vulnerable line in the power grid; if the anticipated N-1 disconnected line does not fall into either of the above two categories, then the anticipated N-1 disconnected line needs to be identified as a vulnerable line in the power grid.
[0062] In the second identification module, the equivalent network of the circuit loop where the expected N-1 disconnected line is located is obtained, including: obtaining the circuit loop where the expected N-1 disconnected line is located from the power grid network diagram under the current operating mode; equi- ...
[0063] In the second identification module, the identification of the grid vulnerable lines of the expected N-1 disconnection line is performed based on the equivalent network, including: searching the grid bridges in the equivalent network, traversing the searched grid bridges, and if there is a grid bridge that causes the equivalent network to be disconnected, the expected N-1 disconnection line is identified as a grid vulnerable line.
[0064] Based on the same technical solution, the present invention also discloses a computer-readable storage medium storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform a method for identifying vulnerable power grid lines.
[0065] Based on the same technical solution, the present invention also discloses a computing device, including one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for performing a method for identifying vulnerable power grid lines.
[0066] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0067] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0068] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0069] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0070] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.
Claims
1. A method for identifying vulnerable power grid lines, characterized in that, include: Power flow calculations are performed based on data about the current operation of the power grid. Based on the power grid topology and power flow calculation results, a power grid bridge search is performed, and the power grid bridge that causes the current power grid to be disconnected is identified as a vulnerable line in the current operating mode. For each anticipated N-1 disconnection line, if the anticipated N-1 disconnection line is identified based on the current operating mode of the power grid vulnerable lines, it is necessary to identify the vulnerable lines of the power grid, obtain the equivalent network of the circuit loop where the anticipated N-1 disconnection line is located, and identify the vulnerable lines of the power grid for the anticipated N-1 disconnection line based on the equivalent network. Among these, identifying vulnerable power grid lines based on the current operating conditions and determining the anticipated N-1 disconnection lines requires vulnerability line identification, including: If the N-1 disconnected line is expected to be one of the multiple circuits, then the N-1 disconnected line does not need to be identified as a vulnerable line in the power grid. If the N-1 disconnected line is a grid bridge and the N-1 disconnected line has been identified under the current operating mode, then the N-1 disconnected line does not need to be identified as a vulnerable grid line. If the anticipated N-1 disconnection line is not one of the two scenarios mentioned above, then the anticipated N-1 disconnection line needs to be identified as a vulnerable line in the power grid.
2. The method for identifying vulnerable power grid lines according to claim 1, characterized in that, The rules for identifying the power bridges that cause the current power grid network to disconnect are as follows: The total active load of the subnet is greater than or equal to the load threshold or the total active power generation is greater than or equal to the power generation threshold; where the subnet is the subnet formed after the grid bridge is disconnected.
3. The method for identifying vulnerable power grid lines according to claim 1, characterized in that, Obtain the equivalent network of the circuit loop containing the anticipated N-1 disconnected circuit, including: From the power grid network diagram under the current operating mode, obtain the circuit loop where the N-1 disconnected line is located; Equivalent values are obtained by equating the power values of the circuit loops and updating the power values of the connection nodes based on the power values of the equivalent lines, thus obtaining an equivalent network containing only circuit loops.
4. The method for identifying vulnerable power grid lines according to claim 1, characterized in that, Identification of vulnerable power grid lines based on the equivalent network for anticipated N-1 disconnection lines, including: Perform a power grid bridge search on the equivalent network, traverse the searched power grid bridges, and if there is a power grid bridge that causes the equivalent network to be disconnected, then identify the expected N-1 disconnected lines as vulnerable lines of the power grid.
5. A system for identifying vulnerable power grid lines, characterized in that, include: The power flow calculation module performs power flow calculations based on data on the current operating mode of the power grid. The first identification module searches for power grid bridges based on the power grid topology and power flow calculation results, and identifies power grid bridges that cause the current power grid network to disconnect as vulnerable lines in the current operating mode. The second identification module, for each expected N-1 disconnection line, if it is determined that the expected N-1 disconnection line needs to be identified as a vulnerable line of the power grid under the current operating mode, obtains the equivalent network of the circuit loop where the expected N-1 disconnection line is located, and identifies the vulnerable line of the power grid for the expected N-1 disconnection line based on the equivalent network. In the second identification module, based on the current operating mode of the power grid vulnerable lines, it determines that the expected N-1 disconnection lines need to be identified as vulnerable lines, including: If the N-1 disconnected line is expected to be one of the multiple circuits, then the N-1 disconnected line does not need to be identified as a vulnerable line in the power grid. If the N-1 disconnected line is a grid bridge and the N-1 disconnected line has been identified under the current operating mode, then the N-1 disconnected line does not need to be identified as a vulnerable grid line. If the anticipated N-1 disconnection line is not one of the two scenarios mentioned above, then the anticipated N-1 disconnection line needs to be identified as a vulnerable line in the power grid.
6. A power grid vulnerable line identification system according to claim 5, characterized in that, In the first identification module, the rule for identifying the power grid bridge that causes the current power grid network to disconnect is as follows: The total active load of the subnet is greater than or equal to the load threshold or the total active power generation is greater than or equal to the power generation threshold; where the subnet is the subnet formed after the grid bridge is disconnected.
7. A computer-readable storage medium for storing one or more programs, characterized in that, The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods according to claims 1 to 3.
8. A computing device, characterized in that, include: One or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods according to claims 1 to 3.