A regional power grid transformer group anti-short circuit capability distributed checking system and method

Abstract

The application discloses a regional power grid transformer group anti-short-circuit capability distributed checking system and method, and relates to the technical field of electric power engineering. The system comprises a distributed sensing module, a transformer group management and control module, a short-circuit checking module, a terminal centralized control module, and is distributed in a local power grid information measurement center, a transformer group management and control center and a regional power grid anti-short-circuit checking and analysis center. The application collects data and preliminarily judges faults through the distributed sensing module, filters faults and transformers to be checked through the transformer group management and control module, performs multi-physical field checking through the short-circuit checking module, and divides risk levels and gives early warnings through the terminal centralized control module. The application solves the problems of low static checking efficiency, difficulty in adapting to power grid changes and insufficient centralized computing power in the prior art, realizes dynamic and distributed checking, and improves the safety and stability of power grid operation and maintenance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric power engineering, and in particular to a distributed checking system and method for the short-circuit resistance of a transformer group in a regional power grid. BACKGROUND

[0002] In the field of electric power engineering, transformers are the core equipment for power transmission and distribution in regional power grids, and their short-circuit resistance directly determines the safety and stability of the power grid. When a short-circuit fault occurs in the power grid, the strong electromagnetic force and instantaneous high temperature generated by the short-circuit current can easily cause deformation of the transformer winding, damage to the insulation, and even scrap the equipment. Therefore, accurate checking of the short-circuit resistance of the transformer is a key link in the operation and maintenance of the power grid.

[0003] Existing transformer short-circuit resistance evaluation techniques have formed a certain research basis. For example, the Chinese patent application with application number 202510428482.9, "Method for evaluating the short-circuit checking resistance of a transformer winding", establishes an electromagnetic force and thermal calculation model and inputs relevant material property data, and obtains stress and temperature distribution data through electromagnetic force and thermal coupling calculation to realize static checking of the short-circuit resistance of the transformer. The Chinese patent application with application number 202211032410.5, "Method for checking the short-circuit resistance and simulating the thermal stability of an operating transformer", further considers the cumulative deformation, residual stress, and thermal stability of the operating transformer winding after being subjected to multiple short-circuit current impacts.

[0004] It can be seen that existing evaluation of the short-circuit resistance of power grid transformers mainly relies on static checking of each transformer before it is connected to the grid, which is low in efficiency. Meanwhile, after the transformer is connected to the regional power grid, the short-circuit current generated may also change accordingly with changes in the grid structure and power grid operation mode. Moreover, there are numerous short-circuit faults in the power grid, and the anti-short-circuit checking center cannot be distributed in each regional power grid due to the high computational requirements, resulting in the inability of existing technologies to use dynamic sensing of short-circuit faults to perform real-time distributed dynamic checking of the impact of short-circuit currents generated by each fault on different operating position transformer groups. SUMMARY

[0005] In order to overcome the shortcomings of existing technologies that cannot dynamically check the short-circuit resistance of transformers according to changes in the grid structure and power grid operation mode, and cannot dynamically analyze the impact of short-circuit impacts in the regional power grid on transformer groups using dynamic sensing, and to solve the problem of insufficient computational power of centralized anti-short-circuit checking, the present application proposes a distributed checking system and method for the short-circuit resistance of a transformer group in a regional power grid.

[0006] In order to achieve the above object, the technical scheme adopted by the present application is as follows: a regional power grid transformer group anti-short circuit capability distributed checking system, the regional power grid comprising a plurality of local power grids, the local power grid being provided with an information measurement center and a transformer group management and control center, the regional power grid being provided with an anti-short circuit checking and analyzing center, a distributed sensing module being arranged at the information measurement center of each local power grid, a transformer group management and control module and a terminal centralized control module being arranged at the transformer group management and control center of each local power grid, and a short circuit checking module being arranged at the anti-short circuit checking and analyzing center;

[0007] The distributed sensing module is used for collecting the operation parameter group and the topology parameter group of the transformer group in real time, and performing normalization, so as to provide data for group coupling calculation and output a standardized group data set to the transformer group management and control module;

[0008] The transformer group management and control module is used for storing the equipment basic parameter group of the local power grid transformer, establishing a transformer-line-node topology association table according to the equipment basic parameter group and the operation parameter group and the topology parameter group data of the distributed sensing module, classifying the short circuit fault types based on the group topology and the transient operation data, calculating the short circuit current of each transformer based on the group impedance data, and outputting to the short circuit checking module; the group impedance data comprises the transformer self impedance, the line impedance and the node impedance of the transformer group;

[0009] The short circuit checking module is used for performing multi-physical field checking on the transformers in the group one by one in priority order, and outputting the group checking result to the terminal centralized control module;

[0010] The terminal centralized control module is arranged at the local power grid transformer group management and control center, and is used for classifying and storing the transformer data in the transformer group, classifying the transformer group risks, and warning the transformers which need to carry out static checking again.

[0011] Further preferably, the distributed sensing module adopts four-feature group dynamic warning trigger conditions based on the current surge, voltage drop, time transient and harmonic distortion of the transformer group, and preliminarily judges whether a short circuit fault occurs, and only when the short circuit fault is judged, the standardized group data set and the fault warning signal are synchronously pushed to the transformer group management and control module; the four-feature group dynamic warning trigger conditions are specifically as follows:

[0012] and and and ;

[0013] Wherein m is the number of transformers affected by the fault connected with the fault node, k is the sequence number of the affected transformer, is the short circuit current peak value of the kth transformer, is the steady state current mean value of the kth transformer before the fault, is the short circuit voltage valley value of the kth transformer, is the rated voltage of the kth transformer, is the fault duration of the kth transformer, is the power frequency cycle, is the total harmonic distortion of the short-circuit current of the kth transformer.

[0014] Further, the transformer group management and control module obtains device basic parameter group, operation parameter group and topology parameter group data in the local power grid for the transformer group in the local power grid, associates the transformers and lines in the data according to the physical node dimension, and associates the transformer transient information according to the time stamp dimension to obtain a transformer-line-node topology association table.

[0015] Further preferably, the transformer group management and control module performs secondary confirmation of the short-circuit fault according to the short-circuit fault perceived by the distributed perception module, and screens the transformer group impacted by the fault:

[0016] The position of the fault point access transformer group is preliminarily screened based on electrical connection, and the transformers directly / indirectly connected by the line are excluded, and the screening condition is: ; is the electrical distance of the kth transformer from the fault point, is the positive sequence equivalent impedance of the kth transformer from the fault point, is the line impedance, is the actual length of the line, is the maximum associated distance of the regional power grid;

[0017] The transformers whose short-circuit current is significantly attenuated due to line impedance are excluded for secondary screening, and only the transformers whose short-circuit current is within the allowable range are retained, and the screening condition is: wherein, is the effective value of the short-circuit current flowing into the kth transformer, is the effective value of the short-circuit current of the fault point, which is obtained by collecting the fault point current transformer data by the distributed perception module; is the short-circuit current attenuation threshold.

[0018] Further preferably, the transformer group management and control module quantifies the impact of the shock on the transformer according to the two-dimensional shock intensity index of the short-circuit current multiple and the duration only when is greater than the shock intensity threshold, it is pushed to the short-circuit checking module:

[0019] ;

[0020] ;

[0021] wherein, The short-circuit current multiple of the kth transformer, , The rated current; The duration of the short-circuit impact on the kth transformer; The impact intensity threshold value, usually 0.6.

[0022] Further preferably, the short-circuit checking module receives the transformer parameters in the checking list pushed by the transformer group management module, performs geometric modeling based on the transformer parameters, generates a three-dimensional geometric model, and then applies the measured transient short-circuit current waveform collected by the distribution perception module as a current excitation to the high, medium and low voltage winding terminals of the transformer;

[0023] The short-circuit checking module applies electromagnetic-force coupled field to check the dynamic stability of the transformer under short-circuit impact; the short-circuit checking module applies electromagnetic-thermal coupled field to check the thermal stability of the transformer under short-circuit impact; the short-circuit checking module feeds back the checking report of whether the dynamic stability index and the thermal stability index of each transformer to be checked meet the standard to the terminal centralized control module.

[0024] Further preferably, the terminal centralized control module receives the checking report, evaluates and classifies the overall risk level of the transformer group in the regional power grid, and based on the evaluation and classification results, implements differentiated cluster management and early warning on the transformers in the group, and uniformly schedules and manages the transformer batches that need to be re-developed for static checking.

[0025] The application also provides a distributed short-circuit resistance checking method for a transformer group in a regional power grid, and the steps are as follows:

[0026] Step one, the distribution perception module connects the power dispatching system and the auxiliary control system, collects, classifies, transmits and stores the operation mode and transformer multi-source state variable data in the local power grid, sets the short-circuit fault warning threshold value based on the transformer rated parameters and the power grid safety criteria, and when the fault warning threshold value is reached, the distribution perception module transmits the fault warning signal and the transformer multi-source state variable data to the transformer group management module;

[0027] Step two, the transformer group management module receives the fault warning signal and the transformer multi-source state variable data pushed by the distribution perception module, performs secondary confirmation and transformer checking selection on the short-circuit fault, and performs impact intensity threshold value determination on the confirmed short-circuit fault;

[0028] Step three, the short-circuit checking module receives the checking request, performs multi-physical field finite element modeling on the transformer to be checked, and checks the impact of the short-circuit fault of the regional power grid on the transformer;

[0029] Step four, the terminal control module classifies the overall risk level of the transformer group according to the checking result, and implements cluster early warning and scheduling decision.

[0030] The application further provides an electronic device comprising a memory and a processor, wherein the memory stores computer executable instructions, and the processor invokes the computer executable instructions to execute each step of the distributed checking method for short-circuit resistance of a transformer group in a regional power grid.

[0031] The application further provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement each step of the distributed checking method for short-circuit resistance of a transformer group in a regional power grid.

[0032] The application has the following advantages:

[0033] The prior art relies on static checking of transformers one by one before being connected to the grid, and cannot adapt to changes in short-circuit current caused by changes in the grid structure and operation mode. In the application, the distributed perception module collects operation and topology parameters in real time, dynamically determines faults in combination with four characteristics of 'current surge - voltage drop - time transient - harmonic distortion', the transformer group management and control module updates the short-circuit current calculation accordingly, and the short-circuit checking module dynamically carries out multi-physical field checking to ensure that the checking result always matches the real-time state of the grid and avoid checking failure caused by changes in the grid.

[0034] The traditional anti-short-circuit checking center cannot be distributed due to high computing power, and cannot cope with numerous short-circuit faults in the grid. The system deploys the distributed perception module and the transformer group management and control module in each local grid, and only the short-circuit checking module is deployed in the regional power grid anti-short-circuit checking analysis center. Data preprocessing, fault preliminary judgment and screening are first completed in the local grid, and only the transformer data that need to be accurately checked are uploaded, which greatly reduces the data transmission volume and centralized computing power consumption, and realizes efficient checking of multiple faults and multiple transformers in the regional power grid.

[0035] The transformer group management and control module excludes irrelevant and weak impact transformers through double screening of electrical distance and short-circuit current attenuation, reducing the number of transformers that need to be checked; the short-circuit checking module adopts a grid division strategy of winding encryption and core and oil tank simplification to save computing power while ensuring accuracy, and carries out dynamic and thermal stability checking according to the IEC standard to ensure the accuracy of the results. The terminal control module classifies and controls according to the checking current ratio and the checking result, realizes differentiated early warning and scheduling, improves the pertinence and efficiency of power grid operation and maintenance, reduces the risk of transformer failure, and ensures the safe and stable operation of the power grid. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a schematic diagram of the distributed checking system for short-circuit resistance of a transformer group in a regional power grid. DETAILED DESCRIPTION

[0037] The application will be further illustrated in detail below in combination with the drawings and examples.

[0038] As shown in the drawings, Figure 1 A regional power grid transformer group anti-short circuit capability distributed checking system, the regional power grid including several local power grids (such as municipal power grids), the local power grid setting information measurement center, transformer group management and control center, the regional power grid setting anti-short circuit checking analysis center, deploying distributed perception modules in the information measurement center of each local power grid, deploying transformer group management and control modules and terminal centralized control modules in the transformer group management and control center of each local power grid, and deploying short circuit checking modules in the anti-short circuit checking analysis center;

[0039] The distributed perception module is used for collecting the operation parameter group of the transformer group, the topology parameter group, and performing normalization, providing data for group coupling calculation and outputting standardized transformer multi-source state variable data to the transformer group management and control module; the operation parameter group includes three-phase current, voltage waveform data, active / reactive power and switch state of the high, medium and low voltage sides of the transformer. The data is derived from the mutual inductor and intelligent terminal installed on the transformer loop. The topology parameter group includes the connection relationship of the transformer, line and circuit breaker, and the number and affiliation area of the node. The data normalization processing includes: unit unification (current unified as kA, voltage unified as kV); time alignment, taking the fault starting time as the time zero point, and performing interpolation synchronization on the transient data of all transformers in the group; format standardization, converting the waveform data into the COMTRADE format of the power system standard, and forming standardized transformer multi-source state variable data.

[0040] The topology parameter group refers to the transformer group-line-node associated topology, which is composed of all transformers, connection lines and access nodes in the local power grid, forms the space-time connection relationship of the local power grid through physical node dimension association (including the hardware connection relationship of the transformer and the access node, line) and time stamp dimension association (including the synchronization of the transformer transient operation data and the fault time), and can directly reflect the electrical conduction path of the fault point and the transformer group.

[0041] The transformer group management and control module is used for storing the device basic parameter group of the local power grid transformer, including the winding inner diameter, outer diameter, axial length, wire resistivity, material elastic modulus, thermal expansion coefficient, core loss parameter of each transformer, transformer manufacturer and production batch, and establishing a transformer-line-node topology association table according to the device basic parameter group and the operation parameter group and topology parameter group data of the distributed perception module; based on the topology parameter group and the transient operation data classification group short circuit fault type, calculating the short circuit current of each transformer based on the group impedance data, and outputting to the short circuit checking module;

[0042] The group impedance data is a core parameter set supporting short-circuit current calculation, including three categories:

[0043] Transformer self impedance: taken from the device basic parameter group, including high, medium and low voltage side unified conversion to 75℃ short-circuit impedance;

[0044] Line impedance: taken from the topology parameter group, including the positive sequence impedance and zero sequence impedance (considering the difference of short-circuit fault type) of all connecting lines between the fault point and the transformer;

[0045] Node impedance: taken from the topology parameter group, including the equivalent impedance of the transformer access node (reflecting the connection strength of the node and the main grid).

[0046] The short-circuit checking module is used to perform multi-physical field checking on the transformers in the group in priority order, and outputs the group checking result to the terminal centralized control module;

[0047] The terminal centralized control module is deployed in the local grid transformer group management and control center, and is used to store the transformer data in the transformer group, classify the transformer group risks, and prewarn the transformers that need to be re-developed static checking.

[0048] The distribution perception module adopts four-feature group dynamic early warning trigger conditions based on transformer group current surge, voltage drop, time transient and harmonic distortion to preliminarily determine whether a short-circuit fault occurs, avoiding single device false triggering.

[0049] Only when it is determined that a short-circuit fault occurs, the standardized group data set (including transformer-line-node topology association table and transient operation data) is synchronously pushed to the transformer group management and control module together with the fault early warning signal, providing data support for subsequent processes.

[0050] The four-feature group dynamic early warning trigger condition is based on the aforementioned collected operation parameter group (three-phase current, voltage, fault recording time, harmonic data), and sets the four-feature group dynamic early warning trigger condition, which is specifically:

[0051] And And And ;

[0052] The above four formulas must be met at the same time to determine that a short-circuit fault is perceived, otherwise it is determined as a non-short-circuit disturbance, and the subsequent process is not triggered. This trigger mechanism can effectively avoid misjudgment caused by single device measurement error. Wherein m is the number of transformer groups affected by the fault connected to the fault node, k is the sequence number of the affected transformer, is the short-circuit current peak value of the kth transformer, is the steady-state current average of the kth transformer before the fault, is the short-circuit voltage valley value of the kth transformer, is the rated voltage of the kth transformer, is the fault duration of the kth transformer, is the power frequency cycle, is the total harmonic distortion of the short-circuit current of the kth transformer.

[0053] Further, the transformer group management and control module obtains device basic parameter group, operation parameter group and topology parameter group data in the local power grid for the transformer group in the local power grid, associates the transformers and lines in the data according to the physical node dimension, and associates the transformer transient information according to the time stamp dimension to obtain a transformer-line-node topology association table, as shown in Table 1.

[0054] Table 1. Transformer-line-node topology association table

[0055]

[0056] Further, the transformer group management and control module performs secondary confirmation of the short-circuit fault according to the short-circuit fault perceived by the distribution perception module, and screens the transformer group impacted.

[0057] The position of the fault point access transformer group is preliminarily screened based on electrical connection, and the transformers directly / indirectly connected by the line are excluded, and the screening condition is: wherein, is the electrical distance of the kth transformer from the fault point, is the positive sequence equivalent impedance of the kth transformer from the fault point, is the line impedance, is the actual length of the line, is the maximum associated distance of the regional power grid (set according to the voltage level, 50 km for 220 kV power grid and 30 km for 110 kV).

[0058] The transformers whose short-circuit current is significantly attenuated due to line impedance are screened out, and only the transformers whose short-circuit current is within the allowable range are retained, and the screening condition is: wherein, is the effective value of the short-circuit current flowing into the kth transformer, is the effective value of the short-circuit current of the fault point, which is obtained by collecting the fault point current transformer data by the distribution perception module; is the short-circuit current attenuation threshold (for transformers of 110 kV and above voltage level 0.3 is taken, that is, when the transformer short-circuit current is <30% of the fault point current, the impact strength is weak and no verification is required).

[0059] Further, the transformer group management and control module performs secondary confirmation of the short-circuit fault according to the short-circuit current multiple and the two-dimensional impact strength index of the duration Quantify the impact of the impact on the transformer, only when greater than the impact intensity threshold, push to the short circuit checking module:

[0060] ;

[0061] ;

[0062] wherein, is the short-circuit current multiple of the kth transformer, , is the rated current; is the duration of the short-circuit impact on the kth transformer; is the impact intensity threshold, usually 0.6 is taken to control.

[0063] Further, the short-circuit checking module receives the transformer parameters in the list to be checked pushed by the transformer group management module, the transformer parameters including winding inner diameter, outer diameter, axial height, wire cake number, support number, wire resistivity, material elastic modulus, thermal expansion coefficient, core loss; Based on the transformer parameters, a three-dimensional geometric model of the winding (multi-strand wire winding), core (laminated structure), clamp and oil tank is automatically generated, the high-voltage side of the 110kV and above transformer is default star connection (neutral point is directly grounded), the medium and low voltage side is default delta connection, and the strategy of winding area encryption and non-critical area simplification is adopted. Specifically: the winding wire and its insulation area are meshed with fine hexahedral grids with a size of less than 5mm; the core, oil tank and other structures are meshed with tetrahedral grids with a size of 20-50mm. This strategy saves computing power while ensuring calculation accuracy. Then the measured transient short-circuit current waveform collected by the distribution perception module is used as current excitation and applied to the transformer high, medium and low voltage winding terminals to solve the transient electromagnetic field and calculate the force on each wire cake of the winding; Time step setting: small step is used within the short-circuit duration to ensure the capture of transient electromagnetic force peak value; large step is used after the duration.

[0064] Further, the short-circuit checking module applies electromagnetic-force coupled field to verify the dynamic stability of the transformer under short-circuit impact, and introduces the electromagnetic force as a load into the structural mechanics module, sets the material properties of the winding copper material such as elastic modulus and Poisson's ratio, solves the transient dynamics equation, and obtains the displacement, stress and strain field of the winding. Based on the method provided in IEC 60076-5 Standard "Power Transformers Part 5: Ability to withstand short circuits", the structural mechanics equation is used to calculate the maximum mechanical stress of the winding under the measured transient short-circuit current. Specifically, the mechanical stress can be calculated by the following formula:

[0065] ;

[0066] wherein, For mechanical stress, E is the elastic modulus of winding material, and ε is the winding strain calculated by the electromagnetic-force coupling field. The maximum mechanical stress divided by the cross-sectional area of the conductor shall be less than the yield strength of the copper conductor for transformers (usually the yield strength of the copper conductor ≥ 160 MPa), otherwise the short-circuit resistance check is judged to be unqualified.

[0067] The thermal stability of the transformer under short-circuit impact is checked by applying the electromagnetic-thermal coupling field. The Joule heat during short-circuit is calculated from the calculated short-circuit current and the DC resistance of the winding, and is taken as a transient heat source. Based on the method provided in IEC 60076-7 Standard “Power Transformers - Part 7: Guide to Loadings for Oil-Immersed Power Transformers”, the thermal conductivity, specific heat capacity of the winding, and the heat dissipation coefficient of the oil to the winding are set in the thermal analysis module, the transient heat source is introduced into the thermal analysis module, the maximum temperature rise of the winding is calculated based on the heat conduction equation in the finite element model under the measured transient short-circuit current, and the thermal stress is calculated according to the maximum temperature rise of the winding and the thermal expansion equation:

[0068] ;

[0069] wherein, is the thermal stress, and α is the thermal expansion coefficient of the winding, is the maximum temperature rise of the winding calculated by the electromagnetic-thermal coupling field, and v is the Poisson's ratio of the winding material, which describes the ratio of the transverse strain to the axial strain of the winding. According to IEC 60076-7 Standard, the maximum temperature rise of the winding shall satisfy that the maximum temperature rise of the winding is less than 80℃ and the thermal stress is less than 200 MPa, otherwise the short-circuit resistance check is judged to be unqualified.

[0070] Further, the short-circuit check module feeds back a check report of “dynamic stability index + thermal stability index + whether to meet the standard” for each transformer to be checked to the terminal control module.

[0071] Further, the terminal control module receives the check report, evaluates and classifies the overall risk level of the transformer group in the regional power grid, and based on the evaluation and classification results (as shown in Table 2), implements differentiated cluster management and early warning for the transformers in the group, and uniformly schedules and manages the transformer batches that need to be redeveloped for static check.

[0072] Table 2

[0073]

[0074] wherein the check current ratio , is the effective value of the measured short-circuit current collected by the distribution perception module, is the peak value of the measured short-circuit current collected by the distribution perception module, is the short-circuit current value selected during the static short-circuit resistance check of the transformer before entering the grid.

[0075] Another embodiment of the present application provides a regional power grid transformer group anti-short circuit capability distributed checking method, the steps are as follows:

[0076] Step one, the distributed perception module connects the power dispatching system and the auxiliary control system, collects, classifies, transmits and stores the operation mode and transformer multi-source state variable data in the local power grid, sets the short circuit fault early warning threshold based on the transformer rated parameters and the power grid safety criteria, when the fault early warning threshold is reached, the distributed perception module transmits the fault early warning signal and the transformer multi-source state variable data to the transformer group management and control module;

[0077] Step two, the transformer group management and control module receives the fault early warning signal and the transformer multi-source state variable data pushed by the distributed perception module, carries out secondary confirmation and transformer checking for short circuit fault, and carries out impact strength threshold determination for the confirmed short circuit fault;

[0078] Step three, the short circuit checking module receives the checking request, carries out multi-physical field finite element modeling for the transformer to be checked, and checks the transformer impact situation according to the short circuit fault of the regional power grid;

[0079] Step four, the terminal centralized control module classifies the overall risk level of the transformer group according to the checking result, and implements cluster early warning and dispatching decision.

[0080] Another embodiment of the present application provides an electronic device, comprising a memory and a processor, the memory stores computer executable instructions, and the processor invokes the computer executable instructions to execute each step of the regional power grid transformer group anti-short circuit capability distributed checking method.

[0081] Another embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize each step of the above-mentioned regional power grid transformer group anti-short circuit capability distributed checking method.

[0082] The above only expresses the preferred embodiments of the present application, and is not other forms of the present application Limitations, any skilled in the art of technical personnel may use the above-mentioned disclosure to make changes or modifications as equivalent embodiments of equivalent changes. However, any simple modification, equivalent change and modification made on the basis of the technical essence of the present application to the above embodiments without departing from the technical scheme content of the present application, still belongs to the protection scope of the present application technical scheme.

Claims

1. A distributed verification system for the short-circuit withstand capability of a regional power grid transformer group, characterized in that, The regional power grid includes several local power grids. Each local power grid has an information measurement center and a transformer group management and control center. The regional power grid has a short-circuit resistance verification and analysis center. Distributed sensing modules are deployed in the information measurement centers of each local power grid. Transformer group management and control modules and terminal centralized control modules are deployed in the transformer group management and control centers of each local power grid. Short-circuit verification modules are deployed in the short-circuit resistance verification and analysis center. The distributed sensing module is used to collect the operating parameter group and topology parameter group of the transformer group in real time, and normalize them to provide data for group coupling calculation and output the standardized group dataset to the transformer group management and control module. The transformer group management module is used to store the basic equipment parameter group of local power grid transformers, and to establish a transformer-line-node topology association table based on the basic equipment parameter group, the operating parameter group and topology parameter group data of the distributed sensing module; The group short-circuit fault types are classified based on group topology and transient operation data. The short-circuit current of each transformer is calculated based on group impedance data and output to the short-circuit verification module. The group impedance data includes the transformer's own impedance, line impedance, and node impedance. The short-circuit verification module is used to perform multi-physics field verification on each transformer in the group according to priority, and output the group verification results to the terminal control module. The terminal control module is deployed in the local power grid transformer group management and control center. It is used to classify and store transformer data in the transformer group, classify the risks of the transformer group, and issue early warnings for transformers that need to be re-verified statically. The distributed sensing module employs a four-feature group dynamic early warning trigger condition based on current surge, voltage drop, time transient, and harmonic distortion of the transformer group to initially determine whether a short-circuit fault has occurred. Only when a short-circuit fault is determined, the standardized group dataset and fault early warning signal are simultaneously pushed to the transformer group management module. The four-feature group dynamic early warning trigger condition is specifically as follows: and and and ; Where m is the number of transformers in the fault-affected group connected to the fault node, and k is the ordinal number of the affected transformer. Let be the peak value of the short-circuit current of the k-th transformer. Let be the average steady-state current before the k-th transformer fails. Let be the valley value of the short-circuit voltage of the k-th transformer. The rated voltage of the kth transformer is... The duration of the fault of the k-th transformer. For power frequency cycle, Total harmonic distortion rate of the short-circuit current of the kth transformer; The transformer group management module performs secondary confirmation of short-circuit faults based on the short-circuit faults detected by the distributed sensing module, and filters the affected transformer groups: Based on initial screening of electrical connections, the location of the fault point connected to the transformer group was identified. Equipment with no electrical connection was excluded based on transformers directly or indirectly connected by lines. Screening criteria: , Let k be the electrical distance between the k-th transformer and the fault point. Let K be the positive sequence equivalent impedance of the k-th transformer and the fault point. For line impedance, This is the actual length of the line. The maximum interconnection distance of the regional power grid; A second screening is conducted, retaining only transformers with short-circuit currents within the allowable range. Screening criteria: ,in, Let RMS value be the short-circuit current flowing into the k-th transformer. The effective value of the short-circuit current at the fault point is obtained by the distributed sensing module collecting data from the current transformer at the fault point. This is the short-circuit current decay threshold.

2. The distributed verification system for the short-circuit withstand capability of regional power grid transformer groups according to claim 1, characterized in that, The transformer group management module acquires basic parameter groups, operating parameter groups, and topology parameter groups of equipment in the local power grid for transformer groups. It associates transformers and lines in the data according to the physical node dimension and associates transformer transient information according to the timestamp dimension to obtain a transformer-line-node topology association table.

3. The distributed verification system for the short-circuit withstand capability of regional power grid transformer groups according to claim 1, characterized in that, The transformer group control module uses a two-dimensional impact intensity index based on the short-circuit current multiple and duration. The impact of quantification shock on transformers only when When the impact strength exceeds the threshold, the signal is sent to the short-circuit verification module. ； ； in, Let be the multiple of the short-circuit current of the k-th transformer. , Rated current; The duration of the short-circuit impact on the k-th transformer; This is the impact strength threshold.

4. The distributed verification system for the short-circuit withstand capability of a regional power grid transformer group according to claim 1, characterized in that, The short-circuit verification module receives transformer parameters from the verification list pushed by the transformer group management module, performs geometric modeling based on the transformer parameters, generates a three-dimensional geometric model, and then uses the measured transient short-circuit current waveform collected by the distributed sensing module as current excitation, which is applied to the high, medium and low voltage winding terminals of the transformer. The short-circuit verification module uses an electromagnetic force coupling field to verify the dynamic stability of the transformer under short-circuit impact; the short-circuit verification module uses an electromagnetic thermal coupling field to verify the thermal stability of the transformer under short-circuit impact; the short-circuit verification module feeds back the verification report of whether the dynamic stability index and thermal stability index of each transformer to be verified meet the standards to the terminal control module.

5. The distributed verification system for the short-circuit withstand capability of a regional power grid transformer group according to claim 1, characterized in that, The terminal control module receives the verification report, assesses and classifies the overall risk level of the transformer group in the regional power grid, and implements differentiated cluster management and early warning for the transformers in the group based on the assessment and classification results. It also performs unified scheduling and management for batches of transformers that need to be re-verified.

6. A distributed verification method for the short-circuit withstand capability of a regional power grid transformer group based on the system described in any one of claims 1-5, characterized in that, The steps are as follows: Step 1: The distributed sensing module connects the power dispatching system and the auxiliary control system to collect, classify, transmit and store the operating mode and transformer multi-source state variable data in the local power grid. Based on the transformer rated parameters and power grid safety criteria, a short-circuit fault early warning threshold is set. When the fault early warning threshold is reached, the distributed sensing module transmits the fault early warning signal and transformer multi-source state variable data to the transformer group management module. Step 2: The transformer group management module receives the fault warning signal and transformer multi-source status variable data pushed by the distributed sensing module, performs secondary confirmation of short-circuit faults and screens transformers that need to be checked, and determines the impact intensity threshold of the confirmed short-circuit faults. Step 3: After receiving the verification request, the short-circuit verification module performs multi-physics finite element modeling on the transformer to be verified, and verifies the transformer impact based on the short-circuit fault of the regional power grid. Step 4: Based on the verification results, the terminal control module classifies the overall risk level of the transformer group and implements clustered early warning and scheduling decisions.

7. An electronic device comprising a memory and a processor, wherein the memory stores computer-executable instructions, characterized in that, The processor invokes computer-executable instructions to execute each step of the distributed verification method for the short-circuit withstand capability of a regional power grid transformer group as described in claim 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements each step of the distributed verification method for the short-circuit withstand capability of regional power grid transformer groups as described in claim 6.

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