Active line shutdown and network reconstruction method to prevent cascading failures during typhoon weather

Abstract

The present invention discloses a method for proactively shutting down power lines and reconfiguring the network to prevent cascading failures during typhoon weather. The method includes the following steps: assembling a main distribution network model, analyzing a set of anticipated faults, assessing power grid risks, and constructing and selecting shutdown and reconfiguration plans. A multi-voltage risk analysis is performed on lines along the typhoon's path to identify potential cascading failures. Some of these lines are proactively shut down, and the network is reconfigured to maximize power supply to residents and critical loads after a line failure occurs during a typhoon. The method provided by the present invention can effectively prevent large-scale power outages in the power grid, is highly operational, and has significant scalability.

Description

Technical Field

[0001] The present invention relates to the field of power grid operation and maintenance, and in particular to a method for actively shutting down lines and reconfiguring networks to prevent cascading failures during typhoon weather. Background Art

[0002] During typhoon weather, N-2 or even Nm faults involving multiple voltage levels often occur along the typhoon's path, often causing chain failures in a short period of time and bringing down the entire local power grid.

[0003] Historical data on power grid disasters include internal data of the power grid and external meteorological data. They also have the characteristics of spatiotemporal attributes, multi-dimensionality, multi-scale, uncertainty, strong periodicity, and high attribute correlation. Using only traditional methods to analyze and process meteorological environmental data will encounter many difficulties, making it difficult to accurately predict the impact of typhoons on the power grid. Summary of the Invention

[0004] In response to the problem that existing technologies find it difficult to accurately predict the impact of typhoons on power grids, the present invention provides a method for proactively shutting down lines and reconfiguring the network to prevent cascading failures during typhoon weather. A risk analysis is performed on lines along the typhoon's path to identify possible cascading failures. Some of these lines are proactively shut down, and the network is reconfigured to ensure maximum power supply to residents and important loads after a line failure occurs during a typhoon.

[0005] The following are the technical solutions of the present invention.

[0006] The method for proactively shutting down lines and reconfiguring the network to prevent cascading failures during typhoon weather includes the following steps:

[0007] Step S1: Obtain the main grid model and measurements from the main grid system, obtain the distribution network model and measurements of the typhoon path from the distribution network system, and splice the main and distribution network models to obtain a main and distribution network splicing model of a regional power grid;

[0008] Step S2: Based on the main distribution network splicing model, typhoon path analysis is performed to identify component groups that may cause faults and provide a multi-voltage mixed expected fault set;

[0009] Step S3: Forecast the load and renewable energy under the typhoon, provide the maximum load and renewable energy forecast values when the typhoon affects the corresponding expected fault set, and perform power flow convergence analysis based on the component state changes of the expected fault set;

[0010] Step S4: Performing a power grid risk assessment considering cascading failures based on the expected fault set;

[0011] Step S5: For the expected fault set with cascading failure risk, shut down the components in each expected fault set one by one, and reconstruct the power grid after the shutdown. The reconstruction goal is to minimize the loss of important loads and residential loads.

[0012] Step S6: Compare and select the reconstruction schemes given for each expected fault set, and finally determine the lines that need to be shut down and the reconstruction scheme for the expected fault set. The switches that have been operated in the expected fault set will not be operated again in the subsequent shutdown and reconstruction of the fault set.

[0013] Preferably, in step S1, the main distribution network model is spliced, including:

[0014] The main network and distribution network models and measurements are exposed in data files in a preset format for parsing. The models and measurements in the main network and distribution network data files are acquired, and the main and distribution networks are spliced using fuzzy matching of 10kV feeder names. The spliced models and measurements are then subjected to state estimation. The flow on each branch and the voltage on the bus are parsed from the state estimation result file, converted into measurements and read in to form a calculable main and distribution network splicing model.

[0015] Preferably, in step S2, performing typhoon path analysis includes:

[0016] A topological analysis is performed based on the main distribution network splicing model, and the main distribution network splicing model is converted into a simplified node-branch model. The typhoon path information is read in, the wind circle level is set, and relevant branches are searched and listed as candidates. Then, historical data analysis is performed to form an expected fault set of branch equipment with high correlation and previous typhoon failures or defects.

[0017] Preferably, the topology analysis includes:

[0018] For closed disconnecting devices, if one side of the disconnecting device is a busbar or unit node and the other side is also a busbar or unit node, the two nodes are merged and the disconnecting device is discarded; if one side of the disconnecting device is a busbar or unit node and the other side is a branch device such as a line or main transformer winding, the branch is directly connected to the node and the disconnecting device is discarded; if one side of the disconnecting device is a branch device such as a line or main transformer and the other side is also a branch device, a virtual node is added, the two branch devices are connected to the virtual node, and the disconnecting device is discarded; the disconnecting device is directly discarded; after this link processing, all disconnecting devices are discarded, and a simplified node-branch model is obtained.

[0019] Preferably, the typhoon path information is read, the wind circle level is set, relevant branches are searched, and listed as candidates, and then historical data analysis is performed to form a predicted fault set of branch devices with high relevance and that have experienced typhoon failures or defects, including:

[0020] The system reads the predicted typhoon path and marks all substations and lines of all voltage levels along the path through which the typhoon winds pass. It then conducts a historical and defect search on these substations and lines. If there are any lines with tower collapses or trips due to typhoons, these components are added to the fault queue. If there are any line or station equipment exceeding their service life, these components are added to the aged queue. If there are any line or station equipment currently operating with defects, these components are added to the unhealthy queue. Components in all three queues are considered as backup branches.

[0021] The alternative branches are disconnected one by one, the power flow is recalculated, and the power flow transfer of the disconnected line to other branches is compared before and after the disconnection. The transfer ratio is defined as the transfer ratio of this link;

[0022] The transfer ratio correlation analysis of all candidate branches was performed using Pearson correlation analysis;

[0023] All data with a transfer ratio greater than 0.1 are sorted out, and all lines are calculated pairwise. If the calculated correlation coefficient is greater than a certain value, it is regarded as two elements of the fault set. If there are three elements with a correlation coefficient greater than a certain value between each two of them, these three elements are regarded as the same fault set.

[0024] Preferably, in step S4, a power grid risk assessment considering cascading failures is performed based on the expected fault set, including: performing power flow calculation and static safety analysis for each model one by one;

[0025] If the base-state power flow calculations for each model exceed the limit, a determination is made as to whether the protection limit has been exceeded. If so, the line is treated as a predicted fault set for cascading failure analysis, and the process proceeds to step S5. If the protection limit has not been exceeded, load shedding simulation is performed to remove unimportant loads and determine whether important loads can be maintained.

[0026] For load power failures that occur during static safety analysis, determine whether there are important loads in these lines and whether these important loads can be transferred to other lines for supply through load transfer;

[0027] For the limit violations that occur in the static safety analysis, a cascading failure analysis is performed. If it is not a cascading failure, the important loads are transferred through load transfer, and the general loads are cut off to eliminate the limit violations. If it is a cascading failure, the process proceeds to step S5.

[0028] Preferably, step S5 includes:

[0029] Based on the power grid structure, the fault sets that can cause cascading failures are disconnected one by one;

[0030] Perform power flow calculations and static safety checks on the disconnected power grid to determine whether cascading faults still exist. If the cascading fault cannot be completely resolved by shutting down any one line in the fault set, shut down both lines until the cascading fault corresponding to the fault set disappears.

[0031] For power grids without cascading failures, grid reconstruction is performed with the goal of minimizing the loss of important loads.

[0032] The present invention also discloses an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor calls the computer program in the memory, it implements the steps of the above-mentioned method for actively shutting down lines and reconstructing the network to prevent typhoon weather chain failures.

[0033] The present invention also discloses a storage medium storing computer-executable instructions. When the computer-executable instructions are loaded and executed by a processor, the steps of the above-mentioned method for actively shutting down lines and reconfiguring the network to prevent typhoon-induced chain failures are implemented.

[0034] The substantial effects of the present invention include:

[0035] A multi-voltage level joint risk analysis was conducted on the lines passing through the typhoon path to identify possible cascading failures. Some of the lines were proactively shut down, and the network was reconstructed based on load forecast data and the grid structure after the shutdown. This ensured that power supply to residents and important loads could be guaranteed to the greatest extent possible after a line failure occurred during a typhoon, solving the problem of local power grid blackouts caused by cascading failures due to severe weather such as typhoons. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a simplified flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] It should be understood that in various embodiments of the present invention, the size of the sequence number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0039] It should be understood that in the present invention, "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0040] It should be understood that in the present invention, "multiple" refers to two or more. "And / or" is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "Contains A, B and C", "Contains A, B, C" means that A, B, and C are all included, "Contains A, B or C" means that one of A, B, and C is included, and "Contains A, B and / or C" means that any one, any two, or any three of A, B, and C are included.

[0041] The technical solution of the present invention is described in detail below with reference to specific embodiments. The embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0042] Example:

[0043] like Figure 1 FIG. 1 is a simplified flow chart of a method for proactively shutting down lines and reconfiguring networks to prevent typhoon-induced cascading failures, provided by this embodiment. The method specifically includes the following steps:

[0044] Step S1: Obtain the main grid model and measurements from the main grid system, obtain the distribution network model and measurements of the typhoon path from the distribution network system, and splice the main and distribution network models to obtain a main and distribution network splicing model of a regional power grid;

[0045] Step S2: Based on the main distribution network splicing model, typhoon path analysis is performed to identify component groups that may cause faults and provide a multi-voltage mixed expected fault set;

[0046] Step S3: Forecast the load and renewable energy under the typhoon, provide the maximum load and renewable energy forecast values when the typhoon affects the corresponding expected fault set, and perform power flow convergence analysis based on the component state changes of the expected fault set;

[0047] Step S4: Performing a power grid risk assessment considering cascading failures based on the expected fault set;

[0048] Step S5: For the expected fault set with cascading failure risk, shut down the components in each expected fault set one by one, and reconstruct the power grid after the shutdown. The reconstruction goal is to minimize the loss of important loads and residential loads.

[0049] Step S6: Compare and select the reconstruction schemes given for each expected fault set, and finally determine the lines that need to be shut down and the reconstruction scheme for the expected fault set. The switches that have been operated in the expected fault set will not be operated again in the subsequent shutdown and reconstruction of the fault set.

[0050] Wherein, in step S1, the main distribution network model is spliced, including:

[0051] The main network and distribution network models and measurements are exposed in data files in a preset format for parsing. The models and measurements in the main network and distribution network data files are acquired, and the main and distribution networks are spliced using fuzzy matching of 10kV feeder names. The spliced models and measurements are then subjected to state estimation. The flow on each branch and the voltage on the bus are parsed from the state estimation result file, converted into measurements and read in to form a calculable main and distribution network splicing model.

[0052] Wherein, in step S2, typhoon path analysis is performed, including:

[0053] A topological analysis is performed based on the main distribution network splicing model, and the main distribution network splicing model is converted into a simplified node-branch model. The typhoon path information is read in, the wind circle level is set, and relevant branches are searched and listed as candidates. Then, historical data analysis is performed to form an expected fault set of branch equipment with high correlation and previous typhoon failures or defects.

[0054] The topology analysis includes:

[0055] For closed disconnecting devices, if one side of the disconnecting device is a busbar or unit node and the other side is also a busbar or unit node, the two nodes are merged and the disconnecting device is discarded; if one side of the disconnecting device is a busbar or unit node and the other side is a branch device such as a line or main transformer winding, the branch is directly connected to the node and the disconnecting device is discarded; if one side of the disconnecting device is a branch device such as a line or main transformer and the other side is also a branch device, a virtual node is added, the two branch devices are connected to the virtual node, and the disconnecting device is discarded; the disconnecting device is directly discarded; after this link processing, all disconnecting devices are discarded, and a simplified node-branch model is obtained.

[0056] The typhoon path information is read, the wind circle level is set, and relevant branches are searched and listed as candidates. Then, historical data analysis is performed to form a predicted fault set of branch devices with high relevance and previous typhoon failures or defects, including:

[0057] The system reads the predicted typhoon path and marks all substations and lines of all voltage levels along the path through which the typhoon winds pass. It then conducts a historical and defect search on these substations and lines. If there are any lines with tower collapses or trips due to typhoons, these components are added to the fault queue. If there are any line or station equipment exceeding their service life, these components are added to the aged queue. If there are any line or station equipment currently operating with defects, these components are added to the unhealthy queue. Components in all three queues are considered as backup branches.

[0058] The alternative branches are disconnected one by one, the power flow is recalculated, and the power flow transfer of the disconnected line to other branches is compared before and after the disconnection. The transfer ratio is defined as the transfer ratio of this link;

[0059] The transfer ratio correlation analysis of all candidate branches was performed using Pearson correlation analysis;

[0060] All data with a transfer ratio greater than 0.1 are sorted out, and all lines are calculated pairwise. If the calculated correlation coefficient is greater than a certain value, it is regarded as two elements of the fault set. If there are three elements with a correlation coefficient greater than a certain value between each two of them, these three elements are regarded as the same fault set.

[0061] In step S4, a power grid risk assessment considering cascading failures is performed based on the expected failure set, including:

[0062] Carry out power flow calculation and static safety analysis for each model one by one;

[0063] If the base-state power flow calculations for each model exceed the limit, a determination is made as to whether the protection limit has been exceeded. If so, the line is treated as a predicted fault set for cascading failure analysis, and the process proceeds to step S5. If the protection limit has not been exceeded, load shedding simulation is performed to remove unimportant loads and determine whether important loads can be maintained.

[0064] For load power failures that occur during static safety analysis, determine whether there are important loads in these lines and whether these important loads can be transferred to other lines for supply through load transfer;

[0065] For the limit violations that occur in the static safety analysis, a cascading failure analysis is performed. If it is not a cascading failure, the important loads are transferred through load transfer, and the general loads are cut off to eliminate the limit violations. If it is a cascading failure, the process proceeds to step S5.

[0066] Wherein, the step S5 includes:

[0067] Based on the power grid structure, the fault sets that can cause cascading failures are disconnected one by one;

[0068] Perform power flow calculations and static safety checks on the disconnected power grid to determine whether cascading faults still exist. If the cascading fault cannot be completely resolved by shutting down any one line in the fault set, shut down both lines until the cascading fault corresponding to the fault set disappears.

[0069] For power grids without cascading failures, grid reconstruction is performed with the goal of minimizing the loss of important loads.

[0070] This embodiment also discloses an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor calls the computer program in the memory, it implements the steps of the above-mentioned method for actively shutting down lines and reconfiguring the network to prevent typhoon weather chain failures.

[0071] This embodiment also discloses a storage medium storing computer-executable instructions. When the computer-executable instructions are loaded and executed by a processor, the steps of the above-mentioned method for actively shutting down lines and reconfiguring the network to prevent typhoon-induced cascading failures are implemented.

[0072] The substantial effects of this embodiment include:

[0073] A multi-voltage level joint risk analysis was conducted on the lines passing through the typhoon path to identify possible cascading failures. Some of the lines were proactively shut down, and the network was reconstructed based on load forecast data and the grid structure after the shutdown. This ensured that power supply to residents and important loads could be guaranteed to the greatest extent possible after a line failure occurred during a typhoon, solving the problem of local power grid blackouts caused by cascading failures due to severe weather such as typhoons.

[0074] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional modules as needed, that is, the internal structure of the specific device can be divided into different functional modules to complete all or part of the functions described above.

[0075] In the embodiments provided in this application, it should be understood that the disclosed structures and methods can be implemented in other ways. For example, the embodiments of the structure described above are merely illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another structure, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, structure or unit, which can be electrical, mechanical or other forms.

[0076] Units described as separate components may or may not be physically separate, and components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0077] In addition, the functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware or software functional units.

[0078] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0079] The above content is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for proactively shutting down lines and reconfiguring networks to prevent cascading failures caused by typhoon weather, characterized in that: The following steps are involved: Step S1: Obtain the main grid model and measurements from the main grid system, obtain the distribution network model and measurements of the typhoon path from the distribution network system, and splice the main and distribution network models to obtain a main and distribution network splicing model of a regional power grid; Step S2: Based on the main distribution network splicing model, typhoon path analysis is performed to identify component groups that may cause faults and provide a multi-voltage mixed expected fault set; Step S3: Forecast the load and renewable energy under the typhoon, provide the maximum load and renewable energy forecast values when the typhoon affects the corresponding expected fault set, and perform power flow convergence analysis based on the component state changes of the expected fault set; Step S4: Performing a power grid risk assessment considering cascading failures based on the expected fault set; Step S5: For the expected fault set with cascading failure risk, shut down the components in each expected fault set one by one, and reconstruct the power grid after the shutdown. The reconstruction goal is to minimize the loss of important loads and residential loads. Step S6: Compare and select the reconstruction solutions provided for each expected fault set, and finally determine the lines that need to be shut down and the reconstruction solution for the expected fault set. Switches that have been operated in the expected fault set will not be operated again in subsequent fault set shutdowns and reconstructions. The step S2 includes: Perform topological analysis based on the main distribution network splicing model and transform the main distribution network splicing model into a simplified node-branch model; The system reads the predicted typhoon path and marks all substations and lines of all voltage levels along the path through which the typhoon winds pass. It then conducts a historical and defect search on these substations and lines. If there are any lines with tower collapses or trips due to typhoons, these components are added to the fault queue. If there are any line or station equipment exceeding their service life, these components are added to the aged queue. If there are any line or station equipment currently operating with defects, these components are added to the unhealthy queue. Components in all three queues are considered as backup branches. The alternative branches are disconnected one by one, the power flow is recalculated, and the power flow transfer of the disconnected line to other branches is compared before and after the disconnection. The transfer ratio is defined as the transfer ratio of this link; The transfer ratio correlation analysis of all candidate branches was performed using Pearson correlation analysis; All data with a transfer ratio greater than 0.1 are sorted out, and all lines are calculated pairwise. If the calculated correlation coefficient is greater than a certain value, it is regarded as two elements of the fault set. If there are three elements with a correlation coefficient greater than a certain value between each two of them, these three elements are regarded as the same fault set.

2. The method for proactively shutting down lines and reconfiguring networks to prevent typhoon-induced cascading failures according to claim 1, characterized in that: In step S1, the main distribution network model is spliced, including: The main network and distribution network models and measurements are exposed in data files in a preset format for parsing. The models and measurements in the main network and distribution network data files are acquired, and the main and distribution networks are spliced using fuzzy matching of 10kV feeder names. The spliced models and measurements are then subjected to state estimation. The flow on each branch and the voltage on the bus are parsed from the state estimation result file, converted into measurements and read in to form a calculable main and distribution network splicing model.

3. The method for proactively stopping lines and reconfiguring networks to prevent typhoon-induced cascading failures according to claim 1, characterized in that: The topology analysis includes: For closed disconnecting devices, if one side of the disconnecting device is a busbar or unit node and the other side is also a busbar or unit node, the two nodes are merged and the disconnecting device is discarded; if one side of the disconnecting device is a busbar or unit node and the other side is a branch device such as a line or main transformer winding, the branch is directly connected to the node and the disconnecting device is discarded; if one side of the disconnecting device is a branch device such as a line or main transformer and the other side is also a branch device, a virtual node is added, the two branch devices are connected to the virtual node, and the disconnecting device is discarded; the disconnecting device is directly discarded; after this link processing, all disconnecting devices are discarded, and a simplified node-branch model is obtained.

4. The method for proactively shutting down lines and reconfiguring networks to prevent typhoon-induced cascading failures according to claim 1, characterized in that: In step S4, a power grid risk assessment considering cascading failures is performed based on the expected fault set, including: Carry out power flow calculation and static safety analysis for each model one by one; If the base-state power flow calculations for each model exceed the limit, a determination is made as to whether the protection limit has been exceeded. If so, the line is treated as a predicted fault set for cascading failure analysis, and the process proceeds to step S5. If the protection limit has not been exceeded, load shedding simulation is performed to remove unimportant loads and determine whether important loads can be maintained. For load power failures that occur during static safety analysis, determine whether there are important loads in these lines and whether these important loads can be transferred to other lines for supply through load transfer; For the limit violations that occur in the static safety analysis, a cascading failure analysis is performed. If it is not a cascading failure, the important loads are transferred through load transfer, and the general loads are cut off to eliminate the limit violations. If it is a cascading failure, the process proceeds to step S5.

5. The method for proactively shutting down lines and reconfiguring networks to prevent typhoon-induced cascading failures according to claim 1, characterized in that: The step S5 comprises: Based on the power grid structure, the fault sets that can cause cascading failures are disconnected one by one; Perform power flow calculation and static safety verification on the disconnected power grid to determine whether there are still cascading faults in the disconnected power grid; If the cascading fault cannot be completely resolved by shutting down any one line in the fault set, both lines will be disconnected until the cascading fault corresponding to the fault set disappears; For power grids without cascading failures, grid reconstruction is performed with the goal of minimizing the loss of important loads.

6. An electronic device, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the method implements the steps of the method for actively shutting down lines and reconstructing the network to prevent typhoon weather chain failures as described in any one of claims 1 to 5.

7. A storage medium, characterized in that: The storage medium stores computer-executable instructions, which, when loaded and executed by the processor, implement the steps of the method for active line shutdown and network reconstruction for preventing typhoon weather cascading failures as described in any one of claims 1 to 5.

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