Intelligent calculation method and system for available power transmission capacity of power transmission section under multiple operation modes

Abstract

The application discloses a kind of multi-operation mode under power transmission section available power transmission capacity intelligent calculation method and system: S1, select multiple power grid operation mode data, obtain multiple power grid operation basic data;S2, define power transmission section parameter;S3, based on the previous power transmission section transmission power value and power transmission section parameter, set section transmission power target value;S4, search sending end generator and receiving end generator, adjust generator output, until reach section transmission power target value;Determine corresponding power grid operation mode;S5, check to the determined power grid operation mode;S6, when the checking result passes, return S3, and re-set section transmission power target value;S7, when the checking result does not pass, determine the previous power transmission section transmission power value as limit power transmission power;S8, multiple power grid operation basic data are executed step S3 to S7, take the minimum power transmission section transmission power value as the allowed power transmission capacity of power transmission section under multiple operation modes.

Description

Technical Field

[0001] This invention relates to the field of power system simulation technology, and more specifically, to an intelligent calculation method and system for the available transmission capacity of a transmission section under multiple operating modes. Background Technology

[0002] Safety and stability are of paramount importance in power production and are the primary tasks of power system dispatch and operation.

[0003] While existing technologies have made significant progress in calculating the available transmission capacity (ATC) of key transmission sections in power grids operating under a single mode, they still lack comprehensive analysis for available transmission capacity under multiple operating modes, especially multiple sections. The complexity of power grid operation modes and the uncertainties brought about by the large-scale integration of new energy sources require calculation methods that can not only handle transmission capacity under a single state but also cover the changing situations under different operating modes. Existing technologies have achieved good application results in ATC calculation, but they generally suffer from drawbacks such as large computational load, insufficient accuracy, and inability to adapt to actual power grid application scenarios. Moreover, most research focuses on ATC calculation for single sections.

[0004] Therefore, studying the available transmission capacity under multiple operating modes is of great practical significance for the stable operation of the power grid and the optimal planning of transmission lines. Summary of the Invention

[0005] This invention proposes an intelligent calculation method and system for the available transmission capacity of a transmission section under multiple operating modes, in order to solve the problem of how to intelligently calculate the available transmission capacity of a transmission section under multiple operating modes based on knowledge and experience.

[0006] To address the aforementioned problems, according to one aspect of the present invention, a method for intelligently calculating the available transmission capacity of a transmission section under multiple operating modes is provided, characterized in that the method comprises: S1, Select multiple sets of power grid operation mode data that support power system power flow and transient stability calculations, and obtain multiple sets of basic power grid operation data; S2, determine the constituent branches of the transmission section, and define the transmission section parameters based on the multiple sets of power grid operation basic data; S3, Based on the transmission power value of the previous transmission section and the parameters of the transmission section, set the target value of the transmission power of the section according to the preset step size factor; S4. Based on the grid topology in the multiple sets of grid operation basic data, search for sending-end generators and receiving-end generators, and adjust the output of sending-end generators and receiving-end generators until the cross-sectional transmission power value reaches the cross-sectional transmission power target value; determine the grid operation mode corresponding to when the cross-sectional transmission power value reaches the cross-sectional transmission power target value; S5, Perform thermal stability verification, static stability verification, and transient stability verification on the determined power grid operation mode, and output the verification results; S6, when the verification result is passed, return to step S3 and reset the cross-sectional transmission power target value; or S7, when the verification result is not passed, the transmission power value of the previous transmission section of the cross-section transmission power target value is determined as the limit transmission power under the corresponding operating mode; S8. Perform steps S3 to S7 on multiple sets of power grid operation basic data respectively, and take the minimum transmission power value of the transmission section as the allowable transmission capacity of the transmission section under multiple operating modes.

[0007] Preferably, the transmission section parameters include: section number, section name, target power of the section, number of branches, branch type, branch name, and power flow direction; The branch types include: AC lines, two-winding transformers, and three-winding transformers on each side; The current flow direction is either in the same direction as or opposite to the original branch.

[0008] Preferably, the step of setting the target value of the transmission power of the transmission section based on the transmission power value of the previous transmission section and the parameters of the transmission section, according to a preset step size factor, includes: Target value of transmission power at the cross section = Transmission power value of the previous transmission section * Step size factor The step size factor is a parameter that can be set by a user.

[0009] Preferably, the step of searching for sending-end generators and receiving-end generators based on the grid topology in the multiple sets of grid operation basic data includes: Based on the power grid topology, the sending-end boundary bus set and the receiving-end boundary bus set are extracted. A branch matrix is ​​constructed based on the determined number of search nodes and the selection rules for crossing voltage levels or not crossing voltage levels. Based on the branch matrix, the sending-end adjustable bus set and the receiving-end adjustable bus set are searched layer by layer. Based on the sending-end adjustable bus set and the receiving-end adjustable bus set, the corresponding unbalanced node generators are selected from the generator data in the multiple sets of power grid operation basic data to generate the sending-end generator set and the receiving-end generator set.

[0010] Preferably, adjusting the output of the sending-end generator and the receiving-end generator includes: S41, increase the active power of each generator in the sending-end generator set by a preset value, randomly select one receiving-end generator from the receiving-end generator set, and decrease the active power of the randomly selected receiving-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the first section growth factor of each sending-end generator, and sort the generators in the sending-end generator set in descending order of the first section growth factor; S42, reduce the active power of each generator in the receiving-end generator set by a preset value, randomly select one generator from the sending-end generator set and increase the active power of the randomly selected sending-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the second section growth factor of each receiving-end generator, and sort the generators in the receiving-end generator set in descending order of the second section growth factor; S43, Select the target sending-end generator that ranks first in the set of sending-end generators, set the valid flag of the target sending-end generator to 1, set the active power to the upper limit of active power, and record the change in the power of the target sending-end generator: If the original value of the valid flag of the target sending generator is 0, then the power change of the target sending generator = the active power limit of the target sending generator; if the original value of the valid flag of the target sending generator is 1, then the power change of the target sending generator = the active power limit of the target sending generator - the current active power of the target sending generator; remove the target sending generator from the set of sending generators; if the set of sending generators is empty, then jump to step S47. S44, Select the target receiving-end generator that ranks first in the receiving-end generator set, set the effective flag of the target receiving-end generator to 0, set the active power to 0, and update the power change of the sending-end generator. The update rule is that the updated power change of the sending-end generator = the power change of the sending-end generator before the update - the initial value of the active power of the target receiving-end generator. Remove the target receiving-end generator from the receiving-end generator set. If the receiving-end generator set is empty, jump to step S47. S45, determine whether the updated power change of the sending-end generator is greater than 0. If so, return to step S44 to perform the receiving-end generator operation until the power change of the sending-end generator is ≤ 0. S46, Perform a power flow calculation to obtain the current cross-sectional power value, and determine whether the current cross-sectional power value is less than the preset cross-sectional transmission power threshold. If so, return to step S43 to continue the sending end generator adjustment operation. S47, Exit generator output adjustment strategy, output the adjusted set of sending-end generators and set of receiving-end generators.

[0011] Preferably, the set of busbars at the sending end boundary is a set of busbars on the branch I side whose power flow direction is in the same direction as the original branch, and a set of busbars on the branch II side whose power flow direction is opposite to the original branch. The receiving end boundary bus set is the set of branch I side buses whose power flow direction is opposite to that of the original branch, and the set of branch II side buses whose power flow direction is in the same direction as that of the original branch.

[0012] Preferably, power flow calculations are performed after adjusting the output of the sending-end generator and the receiving-end generator; If the power flow calculation does not converge, then extreme power flow adjustment is performed, which includes data checking, active power balance adjustment and reactive power balance adjustment.

[0013] Preferably, the data inspection includes component parameter compliance inspection, network connectivity inspection, and power balance inspection; the active power balance adjustment includes zoned power exchange adjustment, balancing machine output adjustment, and generator output exceeding limit adjustment. The reactive power balance adjustment includes switching reactive power compensation equipment according to voltage level or zone, and setting specific bus nodes as PV nodes.

[0014] Preferably, the step of performing thermal stability verification, static stability verification, and transient stability verification on the determined power grid operating conditions, and outputting the verification results, includes: After performing calculations by calling the power flow and transient stability calculation program of the Power System Analysis and Synthesis Program (PSASP), thermal stability verification, static stability verification, and transient stability verification are carried out. When the thermal stability check, static stability check, and transient stability check all meet the corresponding check criteria, the check result is passed.

[0015] Preferably, the verification criterion for thermal stability is: the current result of the branch circuit composed of the cross section does not exceed the upper limit of the thermal stability of the line; The verification criterion for static stability verification is the convergence of power flow calculation; The verification criterion for transient stability is that the system remains transiently stable and does not become unstable after an N-1 three-phase ground fault occurs in the cross-section branch.

[0016] Based on another aspect of the present invention, the present invention provides an intelligent calculation system for the available transmission capacity of transmission sections under multiple operating modes based on knowledge and experience, characterized in that the system comprises: The initial unit is used to execute S1, select multiple sets of power grid operation mode data that support power system power flow and transient stability calculations, and obtain multiple sets of basic power grid operation data. The definition unit is used to execute S2, determine the constituent branches of the transmission section, and define the transmission section parameters based on the multiple sets of power grid operation basic data; The setting unit is used to execute S3, which sets the target value of the transmission power of the transmission section based on the transmission power value of the previous transmission section and the parameters of the transmission section, according to a preset step size factor. The adjustment unit is used to execute S4, based on the grid topology in the multiple sets of grid operation basic data, to search for sending-end generators and receiving-end generators, and adjust the output of sending-end generators and receiving-end generators until the cross-sectional transmission power value reaches the cross-sectional transmission power target value; and determine the grid operation mode corresponding to when the cross-sectional transmission power value reaches the cross-sectional transmission power target value. The verification unit is used to execute S5, perform thermal stability verification, static stability verification, and transient stability verification on the determined power grid operation mode, and output the verification results; it is used to execute S6, when the verification result is passed, return to execute step S3 and reset the cross-sectional transmission power target value; or it is used to execute S7, when the verification result is failed, determine the transmission power value of the previous transmission cross-section as the limit transmission power under the corresponding operation mode; The result unit is used to execute S8, which executes steps S3 to S7 on multiple sets of power grid operation basic data respectively, and takes the minimum transmission power value of the transmission section as the allowable transmission capacity of the transmission section under multiple operating modes.

[0017] Based on another aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of a method for intelligent calculation of the available transmission capacity of a transmission section under multiple operating modes.

[0018] According to another aspect of the present invention, the present invention provides an electronic device, comprising: The aforementioned computer-readable storage medium; and One or more processors for executing a program in the computer-readable storage medium.

[0019] This invention provides an intelligent calculation method and system for the available transmission capacity of a transmission section under multiple operating modes. The method includes: S1, selecting multiple sets of power grid operating mode data that support power flow and transient stability calculations, and obtaining multiple sets of basic power grid operating data; S2, determining the constituent branches of the transmission section, and defining the transmission section parameters based on the multiple sets of basic power grid operating data; S3, setting the target value of the transmission power of the section according to a preset step size factor based on the transmission power value and transmission section parameters of the previous transmission section; S4, searching for sending-end generators and receiving-end generators based on the power grid topology in the multiple sets of basic power grid operating data, and adjusting the output of the sending-end generators and receiving-end generators until the transmission power value of the section reaches the target value of the transmission power of the section; determining the power grid operating mode corresponding to when the transmission power value of the section reaches the target value of the transmission power of the section; S5, performing thermal stability verification, static stability verification, and transient stability verification on the determined power grid operating mode, and outputting the verification results; S6, when the verification result is passed, returning to step S3, and resetting the target value of the transmission power of the section; Alternatively, in step S7, if the verification result is unsuccessful, the transmission power value of the previous transmission section before the target transmission power value is determined as the limit transmission power under the corresponding operating mode; in step S8, steps S3 to S7 are executed on multiple sets of basic grid operation data respectively, and the minimum transmission power value of the transmission section is taken as the allowable transmission capacity of the transmission section under multiple operating modes. This invention's technical solution is based on multiple sets of grid operation mode data for calculation, breaking through the limitations of a single operating mode, making the calculation results of the available transmission capacity of the transmission section more consistent with the multi-scenario characteristics of actual grid operation, and improving the comprehensiveness and applicability of the calculation results. This invention's technical solution adopts the method of "preset step size factor iteratively setting the power target value + unit output adjustment matching the target value" to achieve precise control and target matching of the transmission power of the transmission section, ensuring the consistency between the power setting and the actual transmission, and improving the accuracy of the calculation process. This invention's technical solution integrates thermal stability, static stability, and transient stability triple verification, verifying the safety of grid operation from multiple dimensions, avoiding safety loopholes caused by single stability verification, and ensuring that the calculated transmission power has engineering safety feasibility. This invention's technical solution uses a closed-loop logic of iterative verification and power reset to accurately pinpoint the maximum transmission power under each operating mode. Then, by taking the minimum value from multiple results, the final available transmission capacity is determined, taking into account the safety boundaries of each operating mode and ensuring the absolute safety and reliability of the power grid's transmission operation under multiple operating modes. The entire calculation process of this invention achieves an intelligent closed loop of operating mode selection, parameter definition, power adjustment, stability verification, and result determination, reducing manual intervention, improving the calculation efficiency and automation level of available transmission capacity at transmission sections, and adapting to the needs of rapid power grid dispatch and operation analysis. Attached Figure Description

[0020] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures: Figure 1 This is a flowchart of an intelligent calculation method for the available transmission capacity of a transmission section under multiple operating modes according to an embodiment of the present invention. Figure 2 This is a basic flowchart of the cross-sectional limit power calculation according to an embodiment of the present invention; Figure 3 A flowchart illustrating the process of finding generator nodes according to an embodiment of the present invention; and Figure 4 This is a structural diagram of an intelligent calculation system for the available transmission capacity of a transmission section under multiple operating modes according to an embodiment of the present invention. Detailed Implementation

[0021] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0022] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0023] Figure 1 This is a flowchart of an intelligent calculation method for the available transmission capacity of a transmission section under multiple operating modes according to an embodiment of the present invention. This invention adopts a knowledge-based technical approach, streamlines the calculation process and knowledge rules of actual calculation personnel, and the calculation method is universal, requiring no specific power grid data development training. It also considers the knowledge rules for calculating the available transmission capacity of cross sections under multiple operating conditions, and the calculation results are consistent with the results of manual calculation. This solves the technical problems of poor interpretability, poor data adaptability, and only considering a single operating mode in the prior art.

[0024] This invention directly calls the power flow and transient stability calculation program of PSASP, a power system analysis and synthesis program widely used in actual power grid production and operation, without approximating the power grid. The power flow calculation program has better convergence than the optimization algorithm and can be applied to large-scale power grid data. It solves the problems of insufficient convergence and the use of approximate power flow algorithms in the prior art.

[0025] The purpose of this invention is to provide an intelligent calculation method for the available transmission capacity of a transmission section under multiple operating modes based on knowledge and experience, so as to solve the problem of calculating the available transmission capacity of a section under multiple operating modes.

[0026] like Figure 1 As shown, this invention provides an intelligent calculation method for the available transmission capacity of a transmission section under multiple operating modes. The method includes: S1, Select multiple sets of power grid operation mode data that support power system power flow and transient stability calculations, and obtain multiple sets of basic power grid operation data; This invention first prepares the operating mode data. This invention selects multiple sets of power grid operating mode data, in the format of the widely used domestic power system analysis and synthesis program PSASP 7.94, which must support power system power flow and transient stability calculations.

[0027] S2, determine the constituent branches of the transmission section, and define the transmission section parameters based on multiple sets of power grid operation basic data; Preferably, the transmission section parameters include: section number, section name, target power of the section, number of branches, branch type, branch name, and power flow direction; Branch types include: AC lines, two-winding transformers, and each side of three-winding transformers; The current direction is either the same as or opposite to the original branch.

[0028] This invention performs cross-section selection. It selects a transmission cross-section and determines the constituent branches of that cross-section. The cross-section definition (DEV.SECTION) and the DEV.SECTIONDEV file format are as follows: 1) DEV.SECTION file format: SECTIONNO,'SECTIONNAME',SECTIONPSCH,DEVNUM, The meanings of the fields are as follows:

[0029] 2) DEV.SECTIONDEV file format: SECTIONNO,DEVTYPE,'DEVIDNAME',SIDE, The meanings of the fields are as follows:

[0030] S3, based on the transmission power value and transmission section parameters of the previous transmission section, set the target value of the transmission power of the section according to the preset step size factor; Preferably, based on the transmission power value of the previous transmission section and the transmission section parameters, the target value of the transmission power of the section is set according to a preset step size factor, including: Target value of transmission power at the cross section = Transmission power value of the previous transmission section * Step size factor The step size factor is a parameter that can be set by a user.

[0031] This invention sets a new cross-sectional transmission power target value. Based on the previous cross-sectional transmission power value, the new cross-sectional transmission power target value is set as: previous cross-sectional transmission power value * step size factor. The step size factor can be set by the user and is 1.1 by default.

[0032] S4. Based on the grid topology in multiple sets of grid operation basic data, search for sending-end generators and receiving-end generators, and adjust the output of sending-end generators and receiving-end generators until the cross-sectional transmission power value reaches the cross-sectional transmission power target value; determine the grid operation mode corresponding to the cross-sectional transmission power target value. Preferably, based on the power grid topology in multiple sets of power grid operation basic data, the search for sending-end generators and receiving-end generators includes: Based on the power grid topology, the sending-end boundary bus set and the receiving-end boundary bus set are extracted. A branch matrix is ​​constructed based on the determined number of search nodes and the selection rules for cross-voltage or non-cross-voltage levels. Based on the branch matrix, the sending-end adjustable bus set and the receiving-end adjustable bus set are searched layer by layer. Based on the sending-end adjustable bus set and the receiving-end adjustable bus set, the corresponding unbalanced node generators are selected from the generator data in multiple sets of power grid operation basic data to generate the sending-end generator set and the receiving-end generator set.

[0033] Preferably, adjusting the output of the sending-end generator and the receiving-end generator includes: S51, increase the active power of each generator in the sending-end generator set by a preset value, randomly select one receiving-end generator from the receiving-end generator set, and decrease the active power of the randomly selected receiving-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the first section growth factor of each sending-end generator, and sort the generators in the sending-end generator set in descending order of the first section growth factor; S52, reduce the active power of each generator in the receiving-end generator set by a preset value, randomly select one generator from the sending-end generator set and increase the active power of the randomly selected sending-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the second section growth factor of each receiving-end generator, and sort the generators in the receiving-end generator set in descending order of the second section growth factor; S53, Select the target sending-end generator that ranks first in the set of sending-end generators, set the valid flag of the target sending-end generator to 1, set the active power to the upper limit of active power, and record the change in the power of the target sending-end generator: If the original value of the valid flag of the target sending generator is 0, then the power change of the target sending generator = the active power limit of the target sending generator; if the original value of the valid flag of the target sending generator is 1, then the power change of the target sending generator = the active power limit of the target sending generator - the current active power of the target sending generator; remove the target sending generator from the set of sending generators; if the set of sending generators is empty, then jump to step S57. S54, Select the target receiving-end generator that ranks first in the receiving-end generator set, set the effective flag of the target receiving-end generator to 0, set the active power to 0, and update the power change of the sending-end generator. The update rule is that the updated power change of the sending-end generator = the power change of the sending-end generator before the update - the initial value of the active power of the target receiving-end generator. Remove the target receiving-end generator from the receiving-end generator set. If the receiving-end generator set is empty, jump to step S57. S55, determine whether the updated power change of the sending-end generator is greater than 0. If so, return to step S54 to perform the receiving-end generator operation until the power change of the sending-end generator is ≤ 0. S56, Call the power flow calculation program of the Power System Analysis and Integration Program (PSASP) to perform a power flow calculation, obtain the current cross-section power value, and determine whether the current cross-section power value is less than the preset cross-section transmission power threshold. If so, return to step S53 to continue to perform the sending end generator adjustment operation. S57, Exit generator output adjustment strategy, output the adjusted set of sending-end generators and set of receiving-end generators.

[0034] Preferably, the sending-end boundary bus set is the set of branch I side buses whose power flow direction is in the same direction as the original branch and the set of branch II side buses whose power flow direction is opposite to the original branch. The receiving end boundary bus set is the set of branch I side buses whose power flow direction is opposite to that of the original branch, and the set of branch II side buses whose power flow direction is in the same direction as that of the original branch.

[0035] Preferably, power flow calculations are performed after adjusting the output of the sending-end generator and the receiving-end generator; If the power flow calculation does not converge, extreme power flow adjustment is performed, which includes data checking, active power balance adjustment, and reactive power balance adjustment.

[0036] Preferably, the data inspection includes component parameter compliance inspection, network connectivity inspection, and power balance inspection; the active power balance adjustment includes zone power exchange adjustment, balancing machine output adjustment, and generator output exceeding limit adjustment. Reactive power balance adjustment includes switching reactive power compensation equipment according to voltage level or zone, and setting specific bus nodes as PV nodes.

[0037] This invention searches for sending and receiving units. It utilizes network topology to search for sending and receiving units starting from a cross-section, such as... Figure 3 As shown: The specific steps are as follows: ① Obtain AC line, transformer, and generator data of the power grid from the operation mode data; obtain the sending-end boundary bus set and receiving-end boundary bus set of the cross-section from the cross-section definition data: a) Sending-end boundary bus set of the cross-section: The bus set consisting of the I-side bus of the branch with power flow direction equal to 1 found in the power grid operation mode data, and the II-side bus of the branch with power flow direction equal to 2 found in the power grid operation mode data; b) Receiving-end boundary bus set of the cross-section: The bus set consisting of the I-side bus of the branch with power flow direction equal to 2 found in the power grid operation mode data, and the II-side bus of the branch with power flow direction equal to 1 found in the power grid operation mode data; Set the number of search nodes to the user-input value N; ② If crossing voltage levels is selected, a branch matrix is ​​formed from AC line and transformer data. The branch matrix format is: the first column is the branch number, the second column is the I-side bus, and the third column is the II-side bus. If not crossing voltage levels is selected, a branch matrix is ​​formed only from AC line data. Starting from the cross-section sending-end boundary bus set and receiving-end boundary bus set respectively, find the points connected to these buses in the branch matrix to obtain the first set of bus sets. Then, starting from the first set of bus sets, find the second set of bus sets, and so on, until the number of points found exceeds the specified number of search nodes, and finally form the cross-section sending-end adjustable bus set and the cross-section sending-end adjustable bus set. ③ If you choose to cross voltage levels, proceed directly to the next step; if you choose not to cross voltage levels, search for the points connected to these buses at the next level through the transformer data to form the final adjustable bus set at the cross-section and the adjustable bus set at the cross-section. ④ In the generator data, find generators whose connecting bus is within the adjustable bus set at the sending end of the cross-section, whose node type is not equal to the slack node, and whose valid flag is equal to 0. Add the active power of the found generators to form the adjustable power at the sending end. Then, in the generator data, find generators whose connecting bus is within the adjustable bus set at the sending end of the cross-section, whose node type is not equal to the slack node, whose valid flag is equal to 1, and whose active power is less than the active power limit. Add the active power limit minus the active power of the found generators, and then add it to the adjustable power at the sending end to form the final adjustable power at the sending end. In the generator data, find generators whose connecting bus is within the adjustable bus set at the receiving end of the cross-section, whose node type is not equal to the slack node, and whose valid flag is equal to 1. Add the active power of the found generators to form the adjustable power at the receiving end. ⑤ If the adjustable power at the sending end is greater than the adjustable power at the receiving end, increase the upper limit of the number of nodes searched at the receiving end by 100 and return to step ②; if the adjustable power at the sending end is less than the adjustable power at the receiving end, stop. If step 6 is repeated more than 5 times, proceed directly to the next step; ⑥ Output the final set of sending-end and receiving-end generators.

[0038] 2) Adjust generator output The following generator output adjustment strategy is applied to the sending-end and receiving-end generator sets: ① Increase the active power of each generator in the sending-end generator set by 1 p.u., and decrease the active power of any generator in the receiving-end generator set by 1 p.u. Perform a power flow calculation (call the power flow calculation program of the Power System Analysis and Synthesis Program PSASP), obtain the cross-sectional power value and subtract the initial cross-sectional power value in the original operating mode data to obtain the cross-sectional growth factor of the sending-end generator, and sort the generators in the sending-end generator set from largest to smallest according to the cross-sectional growth factor; ② Decrease the value of each generator in the receiving-end generator set by 1 p.u., and increase the value of any generator in the sending-end generator set by 1 p.u. Perform a power flow calculation (call the power flow calculation program of the Power System Analysis and Synthesis Program PSASP), obtain the cross-sectional power value and subtract the initial cross-sectional power value in the original operating mode data to obtain the cross-sectional growth factor of the receiving-end generator, and sort the generators in the receiving-end generator set from largest to smallest according to the cross-sectional growth factor; ③ Take the generator with the highest ranking in the sending-end generator set, set its validity flag to 1, and its active power to the upper limit of active power. Record the change in power of the sending-end generator: if the original value of the validity flag is 0, the change in power of the sending-end generator = the upper limit of active power of the generator; if the original value of the validity flag is 1, the change in power of the sending-end generator = the upper limit of active power of the generator - the active power of the generator. Remove it from the sending-end generator set; if the sending-end generator set is empty, jump to step ⑦. ④ Take the generator with the highest sorting value in the receiving-end generator set, set its valid flag to 0, its active power to 0, and set the power change of the sending-end generator to the initial value of the generator's active power. Remove it from the receiving-end generator set. If the receiving-end generator set is empty, jump to step ⑦. ⑤ If the change in power output of the sending-end generator is greater than 0, return to step ④ until the change in power output of the sending-end generator is less than or equal to 0. ⑥ Perform a power flow calculation to obtain the cross-sectional power value. If the cross-sectional power value is less than the cross-sectional transmission power value, return to step ③. ⑦ Exit.

[0039] 3) This invention performs extreme power flow adjustment. In step ⑥ of step 2), if the power flow calculation fails to converge, extreme power flow adjustment is performed. ① Data inspection The basic contents of the inspection include: a. Check whether the component parameters conform to the parameter range of the power flow calculation. For AC lines, the positive sequence impedance cannot be 0, and record the branches with an impedance ratio greater than 1; for transformers operating in parallel, their turns ratio and impedance parameters cannot differ by more than 20%. b. Network connectivity check. Check for dead islands; if any are found, disable all components in the dead island. Check for balancing machines in live islands; if none are found, set the generator with the highest power output in that island as a balancing node. c. Check the power balance. Check the statistical data of power generation output and load power of the entire network and each region to determine whether the power generation and load of the entire network and each region are basically balanced.

[0040] ② Active power balance adjustment Active power balancing requires ensuring the active power balance of all generators and loads, and that transmission channels do not exceed limits. The specific methods are as follows: a. Perform zone-based active power statistics to check if the active power exchange between zones is excessive. If the exchange power exceeds the limit, increase the number of units started in the receiving zone and decrease the number of units started in the sending zone, thereby reducing the transmission power of the tie line; b. Check whether the active power output of the balancing machine is reasonable. If the active power output of the balancing machine exceeds its capacity, increase the generator output to bring the active power output of the balancing machine within a reasonable range; c. During adjustment, it is also necessary to check whether the generator output exceeds the limit. If the generator has reached the maximum allowable active power, a new generator needs to be put into operation when increasing the generator output; if the generator has reached the minimum allowable active power, the operating generator needs to be taken out of operation when reducing the generator output.

[0041] ③ Reactive power balance adjustment Reactive power balancing requires the installation of reactive power compensation devices at locations of reactive power imbalance. The specific method is as follows: a. Check the reactive power balance according to voltage level or zone. If reactive power generation is greater than reactive load, disconnect the parallel capacitor or connect the parallel reactor; if reactive power generation is less than reactive load, disconnect the parallel reactor or connect the parallel capacitor. b. Designate nodes where reactive power may be unbalanced as PV nodes. This includes: the maximum error bus node, the heavy load bus node, and the multi-outgoing-line bus node.

[0042] S5 performs thermal stability verification, static stability verification, and transient stability verification on the determined power grid operation mode, and outputs the verification results; Preferably, thermal stability, static stability, and transient stability checks are performed on the determined power grid operating conditions, and the check results are output, including: After performing calculations by calling the power flow and transient stability calculation program of the Power System Analysis and Synthesis Program (PSASP), thermal stability verification, static stability verification, and transient stability verification are carried out. When the thermal stability check, static stability check, and transient stability check all meet the corresponding check criteria, the check result is passed.

[0043] Preferably, the verification criterion for thermal stability is: the current result of the branch circuit composed of the cross section does not exceed the upper limit of the thermal stability of the line; The criterion for static stability verification is the convergence of power flow calculation; The verification criterion for transient stability is that the system remains transiently stable and does not become unstable after an N-1 three-phase ground fault occurs in the cross-section branch.

[0044] This invention performs thermal stability verification, static stability verification, and transient stability verification, with the verification process involving two steps: 1) Perform power flow and transient stability calculations The power flow and transient stability calculation programs of the Power System Analysis and Synthesis Program (PSASP) are invoked to perform power flow and transient stability calculations.

[0045] 2) Verification of Judgment Criteria Thermal stability, static stability, and transient stability checks were performed on the power flow and transient stability calculation results: ① The thermal stability criterion is: the current result of the branch circuit composed of the cross section does not exceed the upper limit of the thermal stability of the line; ② The static stability criterion is: the power flow calculation does not converge; ③ The criterion for transient stability is: when an N-1 fault (three-phase ground fault) occurs in a branch section, the system remains transiently stable and does not become unstable.

[0046] If any one of the above three criteria is not met, the verification fails; if all three criteria are met, the verification passes. If the verification fails, proceed to step (6); if the verification passes, return to step (3). Figure 2 As shown.

[0047] S6, if the verification result is satisfactory, return to step S3 and reset the cross-sectional transmission power target value; or S7, when the verification result is not passed, the transmission power value of the previous transmission section before the target value of the transmission power of the section is determined as the limit transmission power under the corresponding operating mode; S8. Perform steps S3 to S7 on multiple sets of power grid operation basic data respectively, and take the minimum transmission power value of the transmission section as the allowable transmission capacity of the transmission section under multiple operating modes.

[0048] This invention performs multi-operation mode analysis. After the calculation of data from multiple operation modes is completed, the cross-sectional power value is read and the minimum cross-sectional power value is taken as the final intelligent calculation result of the available transmission capacity of the transmission section under multiple operation modes.

[0049] In this invention, to test the effectiveness and adaptability of the proposed method in large-scale power grids, a case study of a 11230-node power grid data system in a certain region is used for verification: 1) Typical operating mode Trend Number: 2024 Upper_North Low 901 (Low Load) Trend Number: 2024 (First Half) - Nanping 111 (Even Load) Trend Number: 2024 Upper_Beigao 801 (High Load) 2) Analyze the cross-section Section A, consisting of five lines: A1-A2I return line, A1-A2II return line, A3-A4I return line, A5-A6I return line, and A5-A6II return line.

[0050] 3) Calculation results The parameters of the intelligent calculation model for the available power transmission capacity of the cross section are set as follows: 1) The generator search range is within 500 busbars connected to the sending and receiving ends of the cross-section, spanning voltage levels; 2) Consider static stability, thermal stability and transient stability constraints, where the fault set of the transient stability constraint is set as N-1 and N-2 faults occurring in the cross-section branch.

[0051] The calculation results are shown in Table 1 below: Table 1

[0052] Transmission capacity of section A (unit: 10,000 kilowatts)

[0053] The final calculation result was taken as the minimum cross-sectional limit power of 5,471 MW under multiple operating modes. The limiting factor was the N-2 fault of the A1-A2I circuit and the A1-A2II circuit. The calculation result was manually calculated and verified by actual analysts, and the result was consistent.

[0054] This invention can be used to calculate the available transmission capacity limit and its limiting factors of key transmission sections of the power grid under multiple operating conditions. It fully automates the calculation of available transmission capacity of transmission sections and greatly improves the efficiency of actual simulation analysis calculation.

[0055] 1. This invention constructs a process framework for calculating the available transmission capacity of a cross section, optimizes the start-up and shutdown strategy of the search unit, and autonomously adjusts the power flow of the non-convergent extreme mode based on knowledge rules.

[0056] 2. This invention automatically verifies different constraints such as static stability, thermal stability, and transient stability, and statistically analyzes multiple calculation results from multiple operating modes to obtain the final cross-sectional available transmission capacity result.

[0057] Figure 4 This is a structural diagram of an intelligent calculation system for the available transmission capacity of a transmission section under multiple operating modes according to an embodiment of the present invention.

[0058] like Figure 4 As shown, this invention provides an intelligent calculation system for the available transmission capacity of a transmission section under multiple operating modes based on knowledge and experience. The system is used to perform: Initial unit 401 is used in S1 to select multiple sets of power grid operation mode data that support power system power flow and transient stability calculations, and to obtain multiple sets of basic power grid operation data. Definition unit 402 is used to execute S2 to determine the constituent branches of the transmission section and define the transmission section parameters based on multiple sets of power grid operation basic data; Preferably, the transmission section parameters include: section number, section name, target power of the section, number of branches, branch type, branch name, and power flow direction; Branch types include: AC lines, two-winding transformers, and each side of three-winding transformers; The current direction is either the same as or opposite to the original branch.

[0059] Setting unit 403 is used to execute S3, which sets the target value of transmission power of the transmission section based on the transmission power value of the previous transmission section and the parameters of the transmission section, according to a preset step size factor; Preferably, based on the transmission power value of the previous transmission section and the transmission section parameters, the target value of the transmission power of the section is set according to a preset step size factor, including: Target value of transmission power at the cross section = Transmission power value of the previous transmission section * Step size factor The step size factor is a parameter that can be set by a user.

[0060] The adjustment unit 404 is used to execute S4, which searches for sending-end generators and receiving-end generators based on the grid topology in multiple sets of grid operation basic data, and adjusts the output of sending-end generators and receiving-end generators until the cross-sectional transmission power value reaches the cross-sectional transmission power target value; and determines the grid operation mode corresponding to the cross-sectional transmission power target value. Preferably, based on the power grid topology in multiple sets of power grid operation basic data, the search for sending-end generators and receiving-end generators includes: Based on the power grid topology, the sending-end boundary bus set and the receiving-end boundary bus set are extracted. A branch matrix is ​​constructed based on the determined number of search nodes and the selection rules for cross-voltage or non-cross-voltage levels. Based on the branch matrix, the sending-end adjustable bus set and the receiving-end adjustable bus set are searched layer by layer. Based on the sending-end adjustable bus set and the receiving-end adjustable bus set, the corresponding unbalanced node generators are selected from the generator data in multiple sets of power grid operation basic data to generate the sending-end generator set and the receiving-end generator set.

[0061] Preferably, adjusting the output of the sending-end generator and the receiving-end generator includes: S41, increase the active power of each generator in the sending-end generator set by a preset value, randomly select one receiving-end generator from the receiving-end generator set, and decrease the active power of the randomly selected receiving-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the first section growth factor of each sending-end generator, and sort the generators in the sending-end generator set in descending order of the first section growth factor; S42, reduce the active power of each generator in the receiving-end generator set by a preset value, randomly select one generator from the sending-end generator set and increase the active power of the randomly selected sending-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the second section growth factor of each receiving-end generator, and sort the generators in the receiving-end generator set in descending order of the second section growth factor; S43, Select the target sending-end generator that ranks first in the set of sending-end generators, set the valid flag of the target sending-end generator to 1, set the active power to the upper limit of active power, and record the change in the power of the target sending-end generator: If the original value of the valid flag of the target sending generator is 0, then the power change of the target sending generator = the active power limit of the target sending generator; if the original value of the valid flag of the target sending generator is 1, then the power change of the target sending generator = the active power limit of the target sending generator - the current active power of the target sending generator; remove the target sending generator from the set of sending generators; if the set of sending generators is empty, then jump to step S47. S44, Select the target receiving-end generator that ranks first in the receiving-end generator set, set the effective flag of the target receiving-end generator to 0, set the active power to 0, and update the power change of the sending-end generator. The update rule is that the updated power change of the sending-end generator = the power change of the sending-end generator before the update - the initial value of the active power of the target receiving-end generator. Remove the target receiving-end generator from the receiving-end generator set. If the receiving-end generator set is empty, jump to step S47. S45, determine whether the updated power change of the sending-end generator is greater than 0. If so, return to step S54 to perform the receiving-end generator operation until the power change of the sending-end generator is ≤ 0. S46, Perform a power flow calculation to obtain the current cross-sectional power value, and determine whether the current cross-sectional power value is less than the preset cross-sectional transmission power threshold. If so, return to step S43 to continue the sending end generator adjustment operation. S47, Exit generator output adjustment strategy, output the adjusted set of sending-end generators and set of receiving-end generators.

[0062] Preferably, the sending-end boundary bus set is the set of branch I side buses whose power flow direction is in the same direction as the original branch and the set of branch II side buses whose power flow direction is opposite to the original branch. The receiving end boundary bus set is the set of branch I side buses whose power flow direction is opposite to that of the original branch, and the set of branch II side buses whose power flow direction is in the same direction as that of the original branch.

[0063] Preferably, power flow calculations are performed after adjusting the output of the sending-end generator and the receiving-end generator; If the power flow calculation does not converge, extreme power flow adjustment is performed, which includes data checking, active power balance adjustment, and reactive power balance adjustment.

[0064] Preferably, the data inspection includes component parameter compliance inspection, network connectivity inspection, and power balance inspection; the active power balance adjustment includes zone power exchange adjustment, balancing machine output adjustment, and generator output exceeding limit adjustment. Reactive power balance adjustment includes switching reactive power compensation equipment according to voltage level or zone, and setting specific bus nodes as PV nodes.

[0065] Verification unit 405 is used to execute S5 to perform thermal stability verification, static stability verification and transient stability verification on the determined power grid operation mode, and output the verification results; Used to execute S6; if the verification result is passed, return to execute step S3 to reset the cross-sectional transmission power target value; or Preferably, thermal stability, static stability, and transient stability checks are performed on the determined power grid operating conditions, and the check results are output, including: After performing calculations by calling the power flow and transient stability calculation program of the Power System Analysis and Synthesis Program (PSASP), thermal stability verification, static stability verification, and transient stability verification are carried out. When the thermal stability check, static stability check, and transient stability check all meet the corresponding check criteria, the check result is passed.

[0066] Preferably, the verification criterion for thermal stability is: the current result of the branch circuit composed of the cross section does not exceed the upper limit of the thermal stability of the line; The criterion for static stability verification is the convergence of power flow calculation; The verification criterion for transient stability is that the system remains transiently stable and does not become unstable after an N-1 three-phase ground fault occurs in the cross-section branch.

[0067] Used to execute S7, when the verification result is not passed, the transmission power value of the previous transmission section before the target value of the transmission power of the section is determined as the limit transmission power under the corresponding operating mode; Result unit 406 is used to execute S8, which executes steps S3 to S7 on multiple sets of power grid operation basic data respectively, and takes the minimum transmission power value of the transmission section as the allowable transmission capacity of the transmission section under multiple operating modes.

[0068] The present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of a method for intelligently calculating the available transmission capacity of a transmission section under multiple operating modes.

[0069] This invention provides an electronic device, comprising: The aforementioned computer-readable storage medium; and One or more processors for executing a program in a computer-readable storage medium.

[0070] The present invention has been described with reference to a few embodiments. However, it will be apparent to those skilled in the art that other embodiments besides those disclosed above fall equivalently within the scope of the present invention.

[0071] Generally, all terms used in this invention are interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed unless explicitly stated otherwise.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus 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.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for intelligently calculating the available transmission capacity of a transmission section under multiple operating modes, characterized in that, The method includes: S1, Select multiple sets of power grid operation mode data that support power system power flow and transient stability calculations, and obtain multiple sets of basic power grid operation data; S2, determine the constituent branches of the transmission section, and define the transmission section parameters based on the multiple sets of power grid operation basic data; S3, Based on the transmission power value of the previous transmission section and the parameters of the transmission section, set the target value of the transmission power of the section according to the preset step size factor; S4, Based on the grid topology in the multiple sets of grid operation basic data, search for sending-end generators and receiving-end generators, and adjust the output of sending-end generators and receiving-end generators until the cross-sectional transmission power value reaches the cross-sectional transmission power target value; determine the grid operation mode corresponding to when the cross-sectional transmission power value reaches the cross-sectional transmission power target value; the step of searching for sending-end generators and receiving-end generators based on the grid topology in the multiple sets of grid operation basic data includes: extracting the sending-end boundary bus set and receiving-end boundary bus set based on the grid topology, constructing a branch matrix based on the determined number of search nodes and the selection rules of cross-voltage or non-cross-voltage levels; based on the branch matrix, searching the sending-end adjustable bus set and receiving-end adjustable bus set layer by layer; based on the sending-end adjustable bus set and the receiving-end adjustable bus set, filtering the corresponding unbalanced node generators from the generator data in the multiple sets of grid operation basic data to generate the sending-end generator set and the receiving-end generator set; The adjustment of the output of the sending-end generator and the receiving-end generator includes: S41, increase the active power of each generator in the sending-end generator set by a preset value, randomly select one receiving-end generator from the receiving-end generator set, and decrease the active power of the randomly selected receiving-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the first section growth factor of each sending-end generator, and sort the generators in the sending-end generator set in descending order of the first section growth factor; S42, reduce the active power of each generator in the receiving-end generator set by a preset value, randomly select one generator from the sending-end generator set and increase the active power of the randomly selected sending-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the second section growth factor of each receiving-end generator, and sort the generators in the receiving-end generator set in descending order of the second section growth factor; S43, Select the target sending-end generator that ranks first in the set of sending-end generators, set the valid flag of the target sending-end generator to 1, set the active power to the upper limit of active power, and record the change in the power of the target sending-end generator: If the original value of the valid flag of the target sending generator is 0, then the power change of the target sending generator = the active power limit of the target sending generator; if the original value of the valid flag of the target sending generator is 1, then the power change of the target sending generator = the active power limit of the target sending generator - the current active power of the target sending generator; remove the target sending generator from the set of sending generators; if the set of sending generators is empty, then jump to step S47. S44, Select the target receiving-end generator that ranks first in the receiving-end generator set, set the effective flag of the target receiving-end generator to 0, set the active power to 0, and update the power change of the sending-end generator. The update rule is that the updated power change of the sending-end generator = the power change of the sending-end generator before the update - the initial value of the active power of the target receiving-end generator. Remove the target receiving-end generator from the receiving-end generator set. If the receiving-end generator set is empty, jump to step S47. S45, determine whether the updated power change of the sending-end generator is greater than 0. If so, return to step S44 and execute all operations in S44 until the power change of the sending-end generator is ≤ 0. S46, perform a power flow calculation. If the power flow calculation does not converge, perform extreme power flow adjustment, obtain the current cross-sectional power value, and determine whether the current cross-sectional power value is less than the preset cross-sectional transmission power threshold. If so, return to step S43 to continue the sending end generator adjustment operation. S47, Exit generator output adjustment strategy, output the adjusted set of sending-end generators and set of receiving-end generators; S5, Perform thermal stability verification, static stability verification, and transient stability verification on the determined power grid operation mode, and output the verification results; S6, when the verification result is passed, return to step S3 and reset the cross-sectional transmission power target value; or S7, when the verification result is not passed, the transmission power value of the previous transmission section of the cross-section transmission power target value is determined as the limit transmission power under the corresponding operating mode; S8. Perform steps S3 to S7 on multiple sets of power grid operation basic data respectively, and take the minimum transmission power value of the transmission section as the allowable transmission capacity of the transmission section under multiple operating modes.

2. The method according to claim 1, characterized in that, The transmission section parameters include: section number, section name, target power of the section, number of branches, branch type, branch name, and power flow direction; The branch types include: AC lines, two-winding transformers, and three-winding transformers on each side; The current flow direction is either in the same direction as or opposite to the original branch.

3. The method according to claim 1, characterized in that, The step of setting the target transmission power value of the transmission section based on the transmission power value of the previous transmission section and the parameters of the transmission section, according to a preset step size factor, includes: Target value of transmission power at the cross section = Transmission power value of the previous transmission section * Step size factor The step size factor is a parameter that can be set by a user.

4. The method according to claim 1, characterized in that, The sending-end boundary bus set is the set of branch I side buses whose power flow direction is in the same direction as the original branch, and the set of branch II side buses whose power flow direction is opposite to the original branch. The receiving end boundary bus set is the set of branch I side buses whose power flow direction is opposite to that of the original branch, and the set of branch II side buses whose power flow direction is in the same direction as that of the original branch.

5. The method according to claim 1, characterized in that, The process of performing thermal stability verification, static stability verification, and transient stability verification on the determined power grid operating conditions, and outputting the verification results, includes: After performing calculations by calling the power flow and transient stability calculation program of the Power System Analysis and Synthesis Program (PSASP), thermal stability verification, static stability verification, and transient stability verification are carried out. When the thermal stability check, static stability check, and transient stability check all meet the corresponding check criteria, the check result is passed.

6. The method according to claim 5, characterized in that, The verification criterion for thermal stability is: the current result of the branch circuit composed of the cross section does not exceed the upper limit of the thermal stability of the line. The verification criterion for static stability verification is the convergence of power flow calculation; The verification criterion for transient stability is that the system remains transiently stable and does not become unstable after an N-1 three-phase ground fault occurs in the cross-section branch.

7. The method according to claim 1, characterized in that, The extreme power flow adjustment includes data checking, active power balance adjustment, and reactive power balance adjustment. The data checks include component parameter compliance checks and network connectivity checks; the active power balance adjustment includes zoned power exchange adjustment, balancing machine output adjustment, and generator output exceeding limits adjustment; the reactive power balance adjustment includes switching reactive power compensation equipment according to voltage level or zone, and setting specific bus nodes as PV nodes.

8. The method according to claim 7, characterized in that, The compliance check method for the component parameters is as follows: for AC lines, the positive sequence impedance cannot be 0, and branches with an impedance ratio greater than 1 are recorded; for transformers operating in parallel, the turns ratio and impedance parameters cannot differ by more than 20%. The network connectivity check is as follows: the power grid is divided into several independent electrical islands according to the AC network connectivity. Check whether there are no generators in the electrical islands. If there are no generators, all components in the electrical islands are set to invalid. Check whether there is at least one generator in the electrical islands whose node type is a balanced node. If not, set the node type of the generator with the largest active power output in the electrical island as a balanced node. The partition power exchange adjustment is as follows: the active power of each partition is statistically analyzed, and it is checked whether the active power exchange between regions is greater than a preset threshold; if the exchange power exceeds the limit, the power-on of the receiving partition is increased and the power-on of the sending partition is reduced. The balancing machine output adjustment is as follows: check whether the active power undertaken by the balancing machine is within its bearing range; if the active power output of the balancing machine exceeds the bearing range, increase the generator output to adjust the active power output of the balancing machine to a reasonable range; the generator output over-limit adjustment is as follows: during the generator output adjustment process, check whether the generator output exceeds the limit; if the generator has reached the maximum allowable active power, a new generator needs to be put into operation when it is necessary to increase the generator output; if the generator has reached the minimum allowable active power, the generator needs to be taken out of operation when it is necessary to reduce the generator output. The method of switching reactive power compensation equipment according to voltage level or zone is as follows: based on the voltage level or zone, reactive power generation and reactive load are statistically analyzed; if reactive power generation is greater than reactive load, the parallel capacitor is deactivated or the parallel reactor is activated; if reactive power generation is less than reactive load, the parallel reactor is deactivated or the parallel capacitor is activated. The designation of specific bus nodes as PV nodes refers to designating nodes with potentially unbalanced reactive power as PV nodes, specifically including: bus nodes with the largest error, heavily loaded bus nodes, and bus nodes with multiple outgoing lines.

9. A smart calculation system for available transmission capacity of a transmission section under multiple operating modes based on knowledge and experience, characterized in that, The system includes: The initial unit is used to execute S1, select multiple sets of power grid operation mode data that support power system power flow and transient stability calculations, and obtain multiple sets of basic power grid operation data. The definition unit is used to execute S2, determine the constituent branches of the transmission section, and define the transmission section parameters based on the multiple sets of power grid operation basic data; The setting unit is used to execute S3, which sets the target value of the transmission power of the transmission section based on the transmission power value of the previous transmission section and the parameters of the transmission section, according to a preset step size factor. The adjustment unit is used to execute S4, which searches for sending-end generators and receiving-end generators based on the grid topology in the multiple sets of grid operation basic data, and adjusts the output of the sending-end generators and receiving-end generators until the cross-sectional transmission power value reaches the cross-sectional transmission power target value; determines the grid operation mode corresponding to the cross-sectional transmission power target value; the step of searching for sending-end generators and receiving-end generators based on the grid topology in the multiple sets of grid operation basic data includes: extracting the sending-end boundary bus set and receiving-end boundary bus set based on the grid topology, constructing a branch matrix based on the determined number of search nodes and the selection rules of cross-voltage or non-cross-voltage levels; searching the sending-end adjustable bus set and receiving-end adjustable bus set layer by layer based on the branch matrix; and filtering the corresponding unbalanced node generators from the generator data in the multiple sets of grid operation basic data to generate the sending-end generator set and the receiving-end generator set based on the sending-end adjustable bus set and the receiving-end adjustable bus set. The adjustment of the output of the sending-end generator and the receiving-end generator includes: S41, increase the active power of each generator in the sending-end generator set by a preset value, randomly select one receiving-end generator from the receiving-end generator set, and decrease the active power of the randomly selected receiving-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the first section growth factor of each sending-end generator, and sort the generators in the sending-end generator set in descending order of the first section growth factor; S42, reduce the active power of each generator in the receiving-end generator set by a preset value, randomly select one generator from the sending-end generator set and increase the active power of the randomly selected sending-end generator by a preset value, perform a power flow calculation, obtain the section power value and subtract the initial section power value in the original operating mode data to obtain the second section growth factor of each receiving-end generator, and sort the generators in the receiving-end generator set in descending order of the second section growth factor; S43, Select the target sending-end generator that ranks first in the set of sending-end generators, set the valid flag of the target sending-end generator to 1, set the active power to the upper limit of active power, and record the change in the power of the target sending-end generator: If the original value of the valid flag of the target sending generator is 0, then the power change of the target sending generator = the active power limit of the target sending generator; if the original value of the valid flag of the target sending generator is 1, then the power change of the target sending generator = the active power limit of the target sending generator - the current active power of the target sending generator; remove the target sending generator from the set of sending generators; if the set of sending generators is empty, then jump to step S47. S44, Select the target receiving-end generator that ranks first in the receiving-end generator set, set the effective flag of the target receiving-end generator to 0, set the active power to 0, and update the power change of the sending-end generator. The update rule is that the updated power change of the sending-end generator = the power change of the sending-end generator before the update - the initial value of the active power of the target receiving-end generator. Remove the target receiving-end generator from the receiving-end generator set. If the receiving-end generator set is empty, jump to step S47. S45, determine whether the updated power change of the sending-end generator is greater than 0. If so, return to step S44 and execute all operations in S44 until the power change of the sending-end generator is ≤ 0. S46, perform a power flow calculation. If the power flow calculation does not converge, perform extreme power flow adjustment, obtain the current cross-sectional power value, and determine whether the current cross-sectional power value is less than the preset cross-sectional transmission power threshold. If so, return to step S43 to continue the sending end generator adjustment operation. S47, Exit generator output adjustment strategy, output the adjusted set of sending-end generators and set of receiving-end generators; The verification unit is used to execute S5, perform thermal stability verification, static stability verification, and transient stability verification on the determined power grid operation mode, and output the verification results; it is used to execute S6, when the verification result is passed, return to execute step S3 and reset the cross-sectional transmission power target value; or it is used to execute S7, when the verification result is failed, determine the transmission power value of the previous transmission cross-section as the limit transmission power under the corresponding operation mode; The result unit is used to execute S8, which executes steps S3 to S7 on multiple sets of power grid operation basic data respectively, and takes the minimum transmission power value of the transmission section as the allowable transmission capacity of the transmission section under multiple operating modes.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method as described in any one of claims 1-8.

11. An electronic device, characterized in that, include: The computer-readable storage medium as described in claim 10; as well as One or more processors for executing a program in the computer-readable storage medium.

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