A power grid risk analysis and early warning method and related device based on sand table deduction

Abstract

The present application discloses a power grid risk analysis and early warning method and related devices based on sand table deduction. Based on the current power grid operation mode and power grid operation status, the status of power grid equipment and telemetry data are obtained to form a new power grid power flow diagram. The dispatcher can adjust the power grid operation mode by performing operations such as opening, closing, and setting for maintenance on the status of lines, switches, and disconnectors. After the operation mode adjustment is successful, when key equipment such as 110 kV main transformers, 110 kV lines, 110 kV busbars, 220 kV main transformers, and 220 kV busbars undergoes an N-1 fault, the computer system scans to determine the possible event levels such as the stations, load numbers, user numbers, and important users that are de-energized due to the N-1 of the equipment, realizing the visualization of real-time power grid risks. At the same time, the load rates of the remaining equipment and key equipment on other power supply paths are calculated to give early warnings for overloaded equipment.

Description

Technical Field

[0001] This application relates to the technical field of power grid risk analysis, and particularly to an adaptive circuit structure of a radio frequency power amplifier. Background Art

[0002] During the operation of the power grid, the power grid usually faces various risks. If these risks threatening the safe operation of the power grid cannot be effectively controlled, it will lead to the occurrence of power grid operation failures, seriously affecting normal power supply.

[0003] Due to the continuous increase in electricity demand, more and more power equipment is connected to the power grid structure, such as newly added power plants, substations, regional small power sources, load lines, etc., making the originally huge power grid structure become even more complex. The gradually expanding power grid structure may have weak links and vulnerable nodes. For example, some important lines are powered in a T-connection form, and some important substations are powered by a single line. Although some substations are designed for dual-line power supply, they do not fully consider whether the load will be overloaded after switching lines. These factors cannot ensure the safe and stable operation of the power grid in the N-1 mode.

[0004] In the prior art, early warning deduction and analysis cannot be performed on the power grid, especially there is no good solution for how to perform different risk analyses on different types of power grids and equipment structures after the operation mode is adjusted. Summary of the Invention

[0005] This application provides a power grid risk analysis and early warning method and related device based on sand table deduction, which is used to solve the technical problem that there is no solution for performing different risk analyses on different types of power grids and equipment structures after the operation mode of the power grid is adjusted.

[0006] In view of this, in the first aspect of this application, a power grid risk analysis and early warning method based on sand table deduction is provided. The method includes:

[0007] S1. Based on the telemetry data of the SCADA system, obtain the real-time operation information of each device in the power grid to be analyzed, and fill the real-time operation information into the blank power flow diagram to generate the real-time power flow diagram of the power grid to be analyzed;

[0008] S2. Adjust the operation mode of the device to be analyzed on the power flow diagram, obtain the first topological path before the operation mode adjustment, determine the area range affected by the operation mode adjustment according to the first topological path, determine the second topological path after the adjustment according to the area range, and compare and analyze the first topological path and the second topological path to determine whether the operation mode adjustment is successful;

[0009] S3. When the operation mode adjustment is successful, obtain the line equipment within the area range, conduct N-1 fault analysis on the line equipment. When an N-1 fault occurs in the line equipment, obtain the stations, load numbers, user numbers, and important users that lose voltage due to the N-1 fault, so as to determine the severity level of the fault event. When the severity level is greater than the preset level, carry out early warning processing; wherein, the line equipment includes: 110 kV main transformers, 110 kV lines, 110 kV busbars, 220 kV main transformers, and 220 kV busbars;

[0010] S4. When the operation mode adjustment is successful, obtain the data at the maximum load moment of the power grid to be analyzed within a preset historical period. According to the maximum load moment data and the second topological path, calculate the load rates of 110 kV line switches, transformer high-side switches, and 10 kV transformer low-side switches, as well as calculate the load rates of 110 kV main transformers and lines, and calculate the load rates of 220 kV substation high-side, medium-side, and low-side switches, and calculate the load rate of 220 kV main transformers. Based on each of the load rates, analyze whether the main transformers, lines, or equipment are overloaded.

[0011] Optionally, step S2 specifically includes:

[0012] S21. Select the equipment to be analyzed from the power grid ledger information table, and query the first topological path before the operation mode adjustment of the equipment to be analyzed; wherein, the equipment to be analyzed includes: switches, disconnectors, busbars, main transformers, and lines;

[0013] S22. According to the first topological path, loop through each piece of equipment to be analyzed, recursively query the affiliated 220 kV substations, and take the union of the 220 kV substations as the affected boundary to obtain the area range;

[0014] S23. According to the area range, re-conduct topological analysis on all the main transformers of the 220 kV substations to obtain the second topological path after the operation mode adjustment;

[0015] S24. Conduct comparative analysis on the first topological path and the second topological path, and judge whether there are 35 kV busbars and 10 kV busbars in the first topological path that do not exist in the second topological path. If not, it is determined that the operation mode adjustment is successful; if so, it is determined that the operation mode adjustment fails.

[0016] Optionally, when the line equipment is the 110 kV main transformer, the N-1 fault analysis on the line equipment specifically includes:

[0017] S31. Obtain the basic information and topological path table of the 110 kV main transformer, screen out the disconnected main transformer high-side switches according to the basic information and the topological path table, and conduct topological analysis to generate a main transformer high-side switch topological path table;

[0018] S32. Screen out the busbars that meet the preset conditions from the main transformer high-side switch topological path table; wherein, the preset conditions include: the busbar exists in the topological path table, the voltage level is 10 kV and there is no maintenance sign hanging on it.

[0019] S33. Determine whether the analyzed busbar meets any of the busbar automatic switching conditions. If so, execute step S34; otherwise, execute step S35. The busbar automatic switching conditions include: 1. The busbar exists in the main transformer high-side switch topological path table, and the main transformer to which the high-side switch belongs is not the same main transformer as the main transformer to which the analyzed busbar belongs; 2. The busbar can be topologically connected to a hot standby low-side switch; 3. The busbar can be topologically connected to a hot standby sectionalizing switch.

[0020] S34. Determine whether the analyzed busbar meets all the conditions of busbar series power supply. If so, execute step S35; otherwise, determine that the analyzed busbar is in a voltage loss state. The busbar series power supply conditions include: there is a superior busbar of the same level and the superior busbar meets the busbar automatic switching conditions.

[0021] S35. Obtain the information of the low-side switch, main transformer and remaining main transformers to which the analyzed busbar belongs, and calculate the load rate of the remaining main transformers.

[0022] S36. Generate the busbar automatic switching power supply analysis result table of the 110 kV main transformer according to the analysis in steps S33 - S35.

[0023] Optionally, calculating the load rates of the 110 kV line switches, high-side switches and 10 kV low-side switches according to the maximum load moment data and the second topological path specifically includes:

[0024] The load of the 10 kV low-side switch is: the sum of the currents of all 10 kV feeders under the 10 kV busbar it supplies, divided by the switch limit value.

[0025] The load rates of the 110 kV line switches and high-side switches are: the sum of the currents of all 10 kV feeders under the 10 kV busbar they supply, divided by 11 and then divided by the switch limit value.

[0026] Optionally, the operation mode adjustment includes: switch load direction adjustment and transfer load calculation.

[0027] Among them, the switch load direction adjustment specifically includes:

[0028] When the switching load has positive and negative directions, it is manually set according to a preset rule, and the preset rule is: set the switch on the 220 kV substation side of the 110 kV line to positive; set the high-side transformer tap to positive and the low-side transformer tap to negative; for the 110 kV line switch, judge through the upper and lower level switches. If the upper load switch is negative, set the switching load to positive; if the upper load switch is positive, set the switching load to negative;

[0029] The transfer load calculation specifically includes:

[0030] Calculate the loads of all high-side transformers, medium-side transformers, medium-side transformers, low-side transformers and line switches in the first topological path and the second topological path. Combine with the second topological path and recursively query downward to query the 10 kV busbars supplied by each switch, and then calculate the switch load by associating all 10 kV feeders under the 10 kV busbar.

[0031] Optionally, after step S2, it further includes:

[0032] When the operation mode adjustment fails, query the 35 kV lines and 10 kV busbars where the first topological path does not exist in the second topological path, take the union to obtain the de-energized busbars.

[0033] The second aspect of the present application provides a power grid risk analysis and early warning system based on sand table deduction, and the system includes:

[0034] An initialization module, configured to obtain the real-time operation information of each device in the power grid to be analyzed based on the telemetry data of the SCADA system, fill the real-time operation information into a blank power flow diagram, and generate a real-time power grid power flow diagram of the power grid to be analyzed;

[0035] An adjustment module, configured to adjust the operation mode of the device to be analyzed on the power grid power flow diagram, obtain the first topological path before the operation mode adjustment, determine the area range affected by the operation mode adjustment according to the first topological path, determine the adjusted second topological path according to the area range, and compare and analyze the first topological path and the second topological path to determine whether the operation mode adjustment is successful;

[0036] A risk analysis module, configured to, when the operation mode adjustment is successful, obtain the line equipment in the area range, perform N-1 fault analysis on the line equipment, when an N-1 fault occurs in the line equipment, obtain the stations, load numbers, user numbers and important users that are de-energized due to the N-1 fault, so as to determine the severity level of the fault event, and perform early warning processing when the severity level is greater than a preset level; wherein, the line equipment includes: 110 kV main transformers, 110 kV lines, 110 kV busbars, 220 kV main transformers and 220 kV busbars;

[0037] The overload analysis module is used to obtain the data at the maximum load moment of the power grid to be analyzed within a preset historical period when the operation mode adjustment is successful, calculate the load rates of the 110 kV line switches, transformer high-voltage switches, and 10 kV transformer low-voltage switches based on the maximum load moment data and the second topological path, calculate the load rates of the 110 kV main transformers and lines, calculate the load rates of the 220 kV substation high-voltage, medium-voltage, and low-voltage switches, calculate the load rate of the 220 kV main transformer, and analyze whether the main transformer, line, or equipment is overloaded based on each of the load rates.

[0038] Optionally, the adjustment module is specifically configured to:

[0039] Select the equipment to be analyzed from the power grid account information table, and query the first topological path of the equipment to be analyzed before the operation mode adjustment; wherein, the equipment to be analyzed includes: switches, disconnectors, busbars, main transformers, and lines;

[0040] Loop through each piece of equipment to be analyzed according to the first topological path, recursively query the 220 kV substations to which they belong, and take the union of the 220 kV substations as the affected boundary to obtain the regional scope;

[0041] Perform a new topological analysis on all the main transformers of the 220 kV substations according to the regional scope, and obtain the second topological path after the operation mode adjustment;

[0042] Compare and analyze the first topological path and the second topological path, and determine whether there are 35 kV busbars and 10 kV busbars in the first topological path that do not exist in the second topological path. If not, it is determined that the operation mode adjustment is successful; if so, it is determined that the operation mode adjustment fails.

[0043] The third aspect of this application provides a power grid risk analysis and early warning device based on sand table deduction, and the device includes a processor and a memory:

[0044] The memory is used to store program code and transmit the program code to the processor;

[0045] The processor is used to execute the steps of the power grid risk analysis and early warning method based on sand table deduction as described in the first aspect above according to the instructions in the program code.

[0046] The fourth aspect of this application provides a computer-readable storage medium, and the computer-readable storage medium is used to store program code, and the program code is used to execute the power grid risk analysis and early warning method based on sand table deduction as described in the first aspect above.

[0047] From the above technical solutions, it can be seen that this application has the following advantages:

[0048] The present application provides a power grid risk analysis and early warning method based on sand table deduction, including: S1. Based on the telemetry data of the SCADA system, obtain the real-time operation information of each device in the power grid to be analyzed, and fill the real-time operation information into a blank power flow diagram to generate a real-time power flow diagram of the power grid to be analyzed; S2. Adjust the operation mode of the device to be analyzed on the power flow diagram of the power grid, obtain the first topological path before the operation mode adjustment, determine the area range affected by the operation mode adjustment according to the first topological path, determine the second topological path after the adjustment according to the area range, and conduct a comparative analysis of the first topological path and the second topological path to determine whether the operation mode adjustment is successful; S3. When the operation mode adjustment is successful, obtain the line devices in the area range, conduct an N-1 fault analysis on the line devices. When an N-1 fault occurs in the line devices, obtain the stations, load numbers, user numbers, and important users that lose voltage due to the N-1 fault, so as to determine the severity level of the fault event. When the severity level is greater than the preset level, early warning processing is performed; where the line devices include: 110 kV main transformers, 110 kV lines, 110 kV busbars, 220 kV main transformers, and 220 kV busbars; S4. When the operation mode adjustment is successful, obtain the data at the maximum load moment in the preset historical period of the power grid to be analyzed. According to the maximum load moment data and the second topological path, calculate the load rates of 110 kV class line switches, transformer high-voltage switches, and 10 kV class transformer low-voltage switches, and calculate the load rates of 110 kV main transformers and lines, and calculate the load rates of 220 kV station transformer high-voltage, medium-voltage, and low-voltage switches, and calculate the load rate of 220 kV main transformers. Based on each load rate, analyze whether the main transformers, lines, or devices are overloaded.

[0049] Based on the current power grid operation mode and power grid operation status, the present application obtains the power grid equipment status and telemetry data to form a new power grid power flow diagram. The dispatcher can perform operations such as opening, closing, and setting for maintenance on the status of lines, switches, and disconnectors to adjust the power grid operation mode. After the operation mode adjustment is successful, the computer system scans to determine the possible event levels when N-1 faults occur in key devices such as 110 kV main transformers, 110 kV lines, 110 kV busbars, 220 kV main transformers, and 220 kV busbars, such as the stations, load numbers, user numbers, and important users that lose voltage due to the device N-1, realizing the visualization of real-time power grid risks. At the same time, calculate the load rates of the remaining devices and key devices on other power supply paths, and give early warnings to overloaded devices. Thus, it solves the technical problem that there is no solution for different types of power grids and equipment structures to perform different risk analyses after the power grid operation mode is adjusted. Brief Description of the Drawings

[0050] Figure 1 It is a schematic flow chart of an embodiment of a power grid risk analysis and early warning method based on sand table deduction provided in an embodiment of the present application;

[0051] Figure 2 It is a schematic structural diagram of an embodiment of a power grid risk analysis and early warning system based on sand table deduction provided in the embodiment of the present application;

[0052] Figure 3 It is a flow chart for analyzing the N-1 fault of the 110 kV main transformer provided in the embodiment of the present application;

[0053] Figure 4 It is a flow chart for analyzing the N-1 fault of the 110 kV line provided in the embodiment of the present application;

[0054] Figure 5 It is a flow chart for analyzing the N-1 fault of the 110 kV bus provided in the embodiment of the present application;

[0055] Figure 6 It is a flow chart for analyzing the N-1 fault of the 220 kV main transformer provided in the embodiment of the present application;

[0056] Figure 7 It is a flow chart for analyzing the N-1 fault of the 220 kV bus provided in the embodiment of the present application;

[0057] Figure 8 It is a flow chart for analyzing overloaded equipment provided in the embodiment of the present application. Specific implementation manners

[0058] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0059] Please refer to Figure 1 , a power grid risk analysis and early warning method based on sand table deduction provided in the embodiment of the present application, includes:

[0060] Step 101: Based on the telemetry data of the SCADA system, obtain the real-time operation information of each device in the power grid to be analyzed, and fill the real-time operation information into the blank power flow diagram to generate the real-time power grid power flow diagram of the power grid to be analyzed;

[0061] It should be noted that in this embodiment, the blank power flow diagram is mainly obtained from other systems first, and then combined with the telemetry data of the SCADA system to obtain information such as the status, current, voltage, and load of the device, and filled into the blank power flow diagram to form a new power grid power flow diagram based on the real-time status.

[0062] Step 102: Adjust the operation mode of the equipment to be analyzed on the power grid flow diagram, obtain the first topological path before the operation mode adjustment, determine the area range affected by the operation mode adjustment according to the first topological path, determine the second topological path after the adjustment according to the area range, and compare and analyze the first topological path and the second topological path to determine whether the operation mode adjustment is successful;

[0063] It should be noted that Step 102 includes the following steps in implementation:

[0064] Step A: Original topological path. Select the analysis object (equipment to be analyzed) from the power grid account information table and query the topological path (original topological path) before the operation mode adjustment. Among them, the analysis objects are switches, disconnectors, busbars, main transformers, lines, etc. operated by users.

[0065] Step B: Affected boundary. According to the topological path (the first topological path) obtained in Step A, loop through each analysis object and recursively query the 220 kV substations to which they belong. Among them, take the union of the 220 kV substations as the affected boundary (area range).

[0066] Step C: Re-topology. According to the affected boundary (area range) obtained in Step B, based on this boundary, re-perform topological analysis on all the main transformers of the 220 kV substations to obtain the topological path (the second topological path) after the operation mode adjustment.

[0067] Step D: Whether voltage loss occurs. According to the results obtained in Step A and Step C, compare the topological paths before and after the operation mode adjustment. Judge whether there are any 35 kV and 10 kV busbars in the topological path of Step A that do not exist in the topological path of Step C. If so, it is determined that the operation mode adjustment fails; otherwise, it is determined that the operation mode adjustment is successful.

[0068] The above is the description of determining whether the operation mode is successfully adjusted in Step 102. Further, the following is the description of further actions after the operation mode adjustment judgment:

[0069] Step E: The operation mode adjustment fails. If the operation mode adjustment fails, query the 35 kV and 10 kV busbars that do not exist in Step C in Step A, take the union to obtain the busbars with voltage loss.

[0070] Step F: The operation mode adjustment is successful. If the operation mode adjustment is successful, query all the high-voltage, medium-voltage, medium-voltage, low-voltage and line switches in Step A and Step C.

[0071] It should be noted that: The operation mode adjustment includes: adjusting the load direction of the switch and calculating the transferred load;

[0072] Among them, the adjustment of the load direction of the switch specifically includes:

[0073] When the switching load has positive and negative directions, it is manually set according to a preset rule. The preset rule is as follows: Set the switch on the 220 kV substation side of the 110 kV line to positive; Set the high-side transformer tap to positive and the low-side transformer tap to negative; For the 110 kV line switch, judge through the upstream and downstream switches. If the upstream load switch is negative, set the switch load to positive. If the upstream load switch is positive, set the switch load to negative.

[0074] Calculating the transferred load specifically includes:

[0075] Calculate the loads of all high-side transformer taps, medium-side transformer taps, medium-side transformer taps, low-side transformer taps and line switches in the first topological path and the second topological path. Combining with the second topological path, recursively query downward to query the 10 kV busbars supplied by each switch, and then calculate the switch load by associating all the 10 kV feeders under the 10 kV busbar.

[0076] Switch load = (Sum of the currents of all 10 kV feeders under the 10 kV busbar) / 58.5.

[0077] Step 103: When the operation mode adjustment is successful, obtain the line equipment within the regional scope, conduct an N-1 fault analysis on the line equipment. When an N-1 fault occurs in the line equipment, obtain the stations, load numbers, user numbers and important users that lose voltage due to the N-1 fault, so as to determine the severity level of the fault event. When the severity level is greater than the preset level, warning processing is carried out; Among them, the line equipment includes: 110 kV main transformers, 110 kV lines, 110 kV busbars, 220 kV main transformers and 220 kV busbars;

[0078] It should be noted that from the "operation mode adjustment", obtain the influence range of the equipment, scan and analyze the 110 kV main transformers, 110 kV lines, 110 kV busbars, 220 kV main transformers and 220 kV busbars and other equipment within the influence range when an N-1 fault occurs (the N-1 principle, also known as the single fault safety inspection rule, which is a technical requirement put forward from the perspective of power grid safe operation), the stations, load numbers, user numbers, important users, etc. that lose voltage, and determine the level of the accident event. The N-1 analysis logic of each type of equipment is as follows:

[0079] (1) N-1 fault analysis of 110 kV main transformer:

[0080] As Figure 3 shown is the N-1 fault analysis flow chart of the 110 kV main transformer in this embodiment.

[0081] Step A: Select the main transformer for analysis from the account information in the SCADA system WEB database, that is, obtain the basic information of the 110 kV main transformer. The main transformer for analysis meets the following conditions: 1. The equipment attribute is the main transformer; 2. The voltage level is 110 kV; 3. No maintenance sign is hung. 4. It is not a power plant step-up transformer.

[0082] Step B: 110 kV main transformer topological path analysis. According to the power flow direction, equipment association relationship, and real-time status of switches and disconnectors, the topological analysis obtains the main transformer topological path table.

[0083] Step C: Screening of disconnected main transformer high-side switches. The main transformer high-side switches meet the following conditions: 1. The equipment attribute is the main transformer high-side switch; 2. The voltage level is 110 kV; 3. No maintenance tag is hung; 4. The switch status is disconnected; 5. The substation to which the high-side switch belongs is the same as the substation to which the main transformer belongs in Step A.

[0084] Step D: Topological path analysis of disconnected main transformer high-side switches. According to the power flow direction, equipment association relationship, and real-time status of switches and disconnectors, the topological analysis obtains the main transformer high-side switch topological path table.

[0085] Step E: Screening and analysis of busbars. The busbars to be analyzed meet the following conditions: 1. Exist in the topological path table; 2. The voltage level is 10 kV; 3. No maintenance tag is hung.

[0086] Step F: Whether the conditions for automatic bus transfer are met. If the analyzed busbar meets any of the following conditions, it can be automatically transferred and proceed to Step G: 1. The busbar exists in the topological path table of the disconnected main transformer high-side switch, and the main transformer to which the high-side switch belongs is not the same as the main transformer to which the analyzed busbar belongs; 2. The busbar can be topologically connected to a hot standby low-side switch of a transformer; 3. The busbar can be topologically connected to a hot standby sectional switch; If the analyzed busbar does not meet any of the above conditions, proceed to Step H.

[0087] Step G: Analyzing the low-side switches, main transformers, and remaining main transformers to which the busbar belongs. 1. Obtain the low-side switches and main transformers to which the busbar belongs according to the main transformer topological path table; 2. Based on the automatic bus transfer switch obtained in Step F and combined with the main transformer topological path table, analyze and obtain the remaining main transformers; 3. Associate with the real-time telemetry value table and transformer table to query the rated capacity of the remaining main transformers, the load measurement points, current measurement points, and current limit values of the main transformer high-side and low-side switches of the remaining main transformers.

[0088] Step H: Whether the conditions for busbar series supply are met. The busbar series supply needs to meet the following conditions: a. There is a superior busbar of the same level; b. The superior busbar meets the conditions for automatic bus transfer.

[0089] Step I: Obtaining the measurement point information of the main transformer. 1. Obtain the low-side switches and main transformers to which the busbar belongs according to the main transformer topological path table; 2. Based on the automatic bus transfer switch obtained in Step F and combined with the main transformer topological path table, analyze and obtain the remaining main transformers; 3. Associate with the real-time telemetry value table and transformer table to query the rated capacity of the remaining main transformers, the load measurement points of the main transformer high-side switches of the remaining main transformers, the current measurement points, and the load measurement points of the main transformer high-side switches to which the busbar belongs.

[0090] Step I: Calculate the remaining main transformer loading rate. 1. Based on the analysis results of Step I, analyze the relationship between the main transformer, the bus, and the remaining main transformers from the perspective of the main transformer to form a result table for the automatic bus transfer of the main transformer. 2. Determine whether the bus supplied by the main transformer has a voltage loss. If so, the remaining main transformer loading rate = (the sum of the currents of all feeders under the bus supplied by the remaining main transformer / 58.5 + the high-side load of the transformer) / the rated capacity of the remaining main transformer; if not, the remaining main transformer loading rate = (the high-side load of the main transformer + the high-side load of the remaining main transformer) / the rated capacity of the remaining main transformer.

[0091] Step J: Based on the analysis results of Steps E - I, form a result table for the analysis of the power sources for the automatic bus transfer of the 110 kV main transformer.

[0092] (2) Analysis of the 110 kV line N - 1 fault:

[0093] As Figure 4 shown in the flowchart for the analysis of the 110 kV line N - 1 fault in this embodiment.

[0094] Step A: Select the switch of the analysis object from the ledger information in the SCADA system WEB database. The switch of the analysis object meets the following conditions: 1. It belongs to the 110 kV switch of the 220 kV substation or the outgoing line switch of the 110 kV power plant; 2. It does not have a maintenance tag; 3. Its name contains "line"; 4. Its name does not contain "test" or "spare".

[0095] Step B: Conduct a topological analysis starting from the line switch. Through the equipment association relationship, conduct a topological analysis according to the power flow direction to form a 110 kV line topological path table, and store the equipment such as buses, switches, and lines on the power supply channel into the database in sequence.

[0096] Step C: Pre - process the line in the following ways: 1. For the case where the power direction is from the line to the 110 kV bus where it is located and the bus has other power supplies, no analysis is conducted. 2. Do not analyze the T - connected line separately, and only use the main line where it is located as the analysis object. 3. For the power plant with a single - circuit line connecting to the grid, its outgoing line is not analyzed.

[0097] Step D: After pre - processing, generate a list of the 110 kV lines to be analyzed and the equipment they supply (110 kV lines, 110 kV main transformers, 110 kV buses of 110 kV substations, 10 kV buses).

[0098] Step E: For any line in the list formed in Step D, if the main transformer or bus it supplies is powered by another line in the list, then list this line as a "line with multiple power sources", and the N - 1 voltage loss has no consequences, and no subsequent analysis is conducted.

[0099] Step F: Conduct the backup power supply automatic switching analysis on the corrected line, obtain the substations powered by the line, and determine whether the substations in the channel are backup-capable.

[0100] Step G: Check whether there are 110 kV bus couplers and line switches that meet the conditions for backup power supply automatic switching. If the switch meets all the following conditions, it can be used for backup power supply automatic switching: 1. In the topological path of the line, there is a hot standby 110 kV bus coupler and line switch at this station; 2. It can be topologically connected from other power source points to the hot standby 110 kV section, bus coupler, and line switch.

[0101] Step H: Traverse the main transformers in the substation powered by the line. For the 110 kV bus couplers and line switches that do not meet the conditions for backup power supply automatic switching in Step G, analyze whether all the main transformers can be used for backup power supply automatic switching by traversing the main transformers in the substation powered by the line. If all the main transformers can be used for backup power supply automatic switching, then this substation can be used for backup power supply automatic switching; otherwise, there is a voltage loss.

[0102] Step I: Traverse the buses powered by the main transformer. Conduct the backup power supply automatic switching analysis on each bus powered by the main transformer one by one. If all the buses powered by the main transformer can be used for backup power supply automatic switching, then the main transformer can be used for backup power supply automatic switching; otherwise, there is a bus with voltage loss.

[0103] Step J: Check whether there are 10 kV section and bus coupler switches that meet the conditions for backup power supply automatic switching. If the bus meets any of the following conditions, it can be used for backup power supply automatic switching: 1. The bus exists in the topological path table of the disconnected main transformer high-voltage side switch, and the main transformer to which the high-voltage side switch belongs is not the same main transformer as the main transformer to which the analyzed bus belongs, and the power supply is different; 2. The bus can be topologically connected to a hot standby low-voltage side switch and the power supply is different; 3. The bus can be topologically connected to a hot standby section switch and the power supply is different;

[0104] Step K: Based on the analysis results of Steps F - J, obtain the voltage loss consequences of all the analyzed object lines and the operation conditions of the backup power supply automatic switching, and form a preliminary 110 kV line backup power supply analysis result table.

[0105] Step L: Correct the pilot backup power supply automatic switching situation. Select the substations with voltage loss from Step K for analysis. If this substation exists in the pilot backup power supply automatic switching maintenance table, then query from the preliminary 110 kV line backup power supply analysis result table whether the other substation paired with the pilot backup power supply automatic switching device of this station has successful backup power supply automatic switching. If successful, then correct this station to indicate no voltage loss.

[0106] Step M: Correct the indirect power supply transfer situation. Select the substations with voltage loss from Step K for further analysis to check whether the following conditions are met: 1. Its upstream power source is an 110 kV substation; 2. The upstream power source substation and this station lose voltage due to the same line fault; 3. Query from the preliminary 110 kV line backup power supply analysis result table that the upstream power source substation has successful backup power supply automatic switching. If the above conditions are met, then correct the result of this station to indicate no voltage loss.

[0107] Step N: Obtain the measuring point information of the line. 1. Obtain the line switches according to the 110 kV line topology path table; 2. Based on the backup power supply switches obtained in Step K and combined with the 110 kV line topology path table, analyze and obtain the remaining lines; 3. Associate the real-time telemetry value table and the transformer table, and query and analyze the load measuring points and current measuring points of the line switches of the line; the load measuring points and current measuring points of the line switches of the remaining lines.

[0108] Step O: Calculate the load rate of the remaining lines. By associating the 110 kV line backup power supply analysis result table, the 110 kV line topology path analysis table, the real-time telemetry value table, and the power grid equipment table, analyze and obtain the load rate of the remaining lines.

[0109] Step P: Based on the comprehensive F - O analysis results, obtain the voltage loss consequences, backup power supply operation conditions, and load rates of the remaining lines of all the analyzed object lines, and form the 110 kV line backup power supply analysis result table.

[0110] (3) 110 kV bus N - 1 fault analysis:

[0111] As Figure 5 shown is the flowchart of the 110 kV bus N - 1 fault analysis in this embodiment.

[0112] Step 1, 110 kV bus association and grouping: 1) Generate the bus pairing table. Obtain the topological association information of the 110 kV bus coupler switch in the 220 kV substation. If both sides of the bus coupler switch are associated with two sections of buses, then save the buses with this structure in the bus pairing table. If one side of the switch is associated with a switch and the other side is associated with a bus, then continue to perform topology on the switch until it stops at a switch or a bus, and save the multiple sections of buses obtained through topology in the bus pairing table. 2) Starting from any section of bus M1, perform power grid power flow topology to find all the 110 kV buses in this 220 kV substation that are powered by M1. If this bus is in the bus pairing table with M1, then it is determined that M1 fails and loses voltage, and this bus loses voltage simultaneously. If this bus is not in the bus pairing table, then it is necessary to determine whether this bus is only powered by M1. If this bus can be powered by other buses in this 220 kV substation or the 220 kV main transformer, then it is determined that it does not lose voltage; otherwise, it is determined that M1 fails and loses voltage, and this bus loses voltage simultaneously.

[0113] Step 2, 110kV line backup automatic switching process analysis: through topological relationships and real-time equipment status data, obtain the set of lines L{L1, L2...} with active load >-0.3MW on all buses M{M1, M2...}, topologically analyze the substations supplied by each line, and analyze the consequences of backup automatic switching according to the main transformer backup automatic switching type maintenance table and the longitudinal backup automatic switching maintenance table. If there is no backup power supply or the new power supply channel can still be traced back to the faulty bus after the backup automatic switching action, it is determined that the voltage is lost. In other cases, the backup automatic switching is successful and no voltage loss is caused. For user substations, no backup automatic switching judgment is made, and the busbar fault to which it supplies power will directly cause voltage loss.

[0114] Step 3, forming a preliminary analysis report: Summarize the analysis results of step 2 and write them into the fault consequence information of the corresponding bus to form the fault analysis results of a single bus. After analyzing each item one by one, summarize them to form a preliminary analysis report.

[0115] Step 4, correction of the power supply situation of multiple power sources in the preliminary analysis report: Correct the power supply situation of multiple power points in the preliminary analysis report obtained in step 3. The topological analysis obtains the pairing of all lines from multiple power points to the same substation, and determines one by one whether all the lines in the pairing exist in the analysis report formed in step 3. If all exist, there is no need to correct the consequences. If only some exist, the consequences of the lines in the pairing that exist in the preliminary analysis report are corrected to no pressure loss.

[0116] Step 5, correction of multiple backup automatic switching situations in the preliminary analysis report: Analyze the substations without backup power supply in the preliminary analysis report obtained in step 3 to determine whether there is such a situation: its backup upper power supply is a 110kV substation, and the substation loses voltage due to the same bus failure, and can restore power supply after a backup automatic switching action. If so, correct the result to no voltage loss.

[0117] Step 6, determination of voltage loss in the entire station: Determine whether the substation with voltage loss result in the revised analysis report is marked as voltage loss in the entire station: if all the equipment in the station is powered by the same power supply, and there is no unloaded busbar and main transformer powered by other power supplies, it is determined to be voltage loss in the entire station, otherwise the consequences of voltage loss are calculated according to the number of 10kV busbars with voltage loss.

[0118] Step 7, form the final risk report: Combining the analysis report corrected by steps 4 and 5 and the judgment result of S6, form an automatic scanning analysis report on the risks of all 110kV busbars N-1.

[0119] (4) 220kV main transformer N-1 fault analysis:

[0120] like Figure 6 Shown is the fault analysis flow chart of 220kV main transformer N-1 in this embodiment.

[0121] Step S1: Select the analysis object from the ledger information in the SCADA system WEB database. The analysis object meets the following conditions: 1. The equipment attribute is the main transformer; 2. The voltage level is 220 kV; 3. There is no maintenance sign hung; 4. It is not a power plant step-up transformer.

[0122] Step S2: Analyze the power supply range of the main transformer of the analysis object. Starting from the main transformer body, according to the power flow direction, perform topology analysis on the low-voltage side and the medium-voltage side respectively. The topology analysis on the low-voltage side stops after reaching the 10 kV bus of this station; for the medium-voltage side, perform topology analysis along the path of the medium-voltage switch - the 110 kV bus of this station - the 110 kV outgoing line of this station - the 110 kV substation bus or line-transformer unit high-voltage switch on the opposite side - the main transformer and 10 kV bus line of the 110 kV substation on the opposite side. For the parallel-running 110 kV buses, the power direction of the bus tie is not considered during topology analysis. After the topology analysis is completed, save all the equipment on the topology path of the 220 kV main transformer of the analysis object and the disconnecting switch or switch isolated from other parts of the power grid as the power supply range of the 220 kV main transformer of the analysis object in the system.

[0123] Step S3: Determine the operation mode of the main transformer within this station. For all the power supply ranges of the main transformers within this station obtained in Step S2, if the power supply ranges of any two main transformers on the medium-voltage side are exactly the same, it is determined to be in a parallel operation mode; otherwise, it is determined to be in a split operation mode.

[0124] Step S4: Conduct the N-1 risk analysis of the main transformer for the case determined to be in the split operation mode in Step S3.

[0125] Step S5: Conduct the N-1 risk analysis of the main transformer for the case determined to be in the parallel operation mode in Step S3.

[0126] In the above Step S4, conducting the N-1 risk analysis of the main transformer for the case determined to be in the split operation mode in Step S3 includes:

[0127] S401: Take any 110 kV substation and the equipment it contains (110 kV bus, main transformer, 10 kV bus) obtained from the topology analysis in the medium-voltage side direction in Step S2 as elements, and form a set of all elements and store it in the system.

[0128] S402: Determine whether any substation obtained in Step S401 belongs to the 110 kV substations in the user substation maintenance table. If it belongs, directly determine that the station will lose voltage after the N-1 of the main transformer, and no subsequent analysis is required.

[0129] S403: For the 110kV substation determined in step S402 as not belonging to the user's substation maintenance table, if any main transformer high-voltage switch contained in the station also exists in the power supply range of other 220kV operating main transformers except the main transformer of the analysis object obtained in step S2, then it is determined that the main transformer of the station and the 10kV bus it supplies and the connected 110kV bus are all multi-power supply equipment. After the main transformer of the analysis object N-1, the above equipment will not cause voltage loss.

[0130] S404: For any element in the set obtained in step S401, if it does not meet the multi-power supply conditions listed in step S403, and the element contains all the operating equipment of the station (110kV bus, main transformer, 10kV bus), it is determined that the 110kV substation has a short-term voltage loss after the main transformer N-1 of the analysis object.

[0131] S405: For the 110kV substation that is judged as having a short-term voltage loss in the entire station in step S404, determine whether it meets the following 110kV line standby automatic switching conditions: 1. The station has a hot standby 110kV line switch; 2. The line switch exists in the power supply range of other 220kV operating main transformers except the main transformer of the analysis object obtained in step S2. If so, it is determined that the 110kV line standby automatic switching of the station is successful, and the station does not cause voltage loss after the main transformer of the analysis object N-1.

[0132] S406: For substations that do not meet the conditions listed in step S405, further analyze whether they meet the main transformer standby automatic switch conditions: 1. The station has a hot standby main transformer; 2. The main transformer is in the main transformer standby automatic switch maintenance table; 3. The main transformer high switch exists in the power supply range of other 220kV operating main transformers except the main transformer of the analysis object obtained in step S2. If the above conditions are met, it is determined that after the main transformer of the analysis object N-1, the 110kV main transformer standby automatic switch of the station is successful without causing voltage loss.

[0133] S407: For the 110kV substation that is determined as not losing voltage for the entire station for a short time after the main transformer N-1 of the analysis object in step S404, determine whether it meets the 110kV section standby automatic switching conditions: 1. The station has a hot standby 110kV section switch; 2. The section switch exists in the power supply range of other 220kV operating main transformers except the main transformer of the analysis object obtained in step S2. If it meets the conditions, it is determined that the 110kV section standby automatic switching of the station is successful, and after the main transformer N-1 of the analysis object, no equipment of the station loses voltage.

[0134] S408: For substations that do not meet the 110 kV sectional backup power supply self - closing conditions listed in step S407, judge one by one whether the 10 kV bus with short - term voltage loss meets the main transformer backup power supply self - closing conditions: 1. The de - energized bus can be topologically connected to the low - voltage side switch of a hot - standby main transformer; 2. This hot - standby main transformer is in the main transformer backup power supply self - closing maintenance list; 3. The high - voltage side switch of this hot - standby main transformer exists in the power supply scope of other 220 kV operating main transformers except the analyzed main transformer obtained in step S2. If the above conditions are met, it is determined that after the analyzed main transformer undergoes N - 1, the main transformer backup power supply self - closing of the 10 kV bus is successful and there will be no voltage loss.

[0135] S409: For substations that do not meet the conditions listed in step S408, judge one by one whether the 10 kV bus with short - term voltage loss meets the 10 kV sectional backup power supply self - closing conditions: 1. The de - energized bus can be topologically connected to a hot - standby sectional switch; 2. The other bus connected to this hot - standby sectional switch is powered by the low - voltage side switch of the main transformer to which it is connected; 3. This hot - standby sectional switch exists in the power supply scope of other 220 kV operating main transformers except the analyzed main transformer obtained in step S2. If the above conditions are met, it is determined that after the analyzed main transformer undergoes N - 1, the sectional backup power supply self - closing of the 10 kV bus is successful and there will be no voltage loss.

[0136] S410: Based on the analysis results (voltage - loss equipment, backup power supply self - closing operation status) of steps S405 - S409, form a preliminary consequence analysis report after the analyzed main transformer undergoes N - 1.

[0137] S411: For the voltage - loss equipment in the preliminary consequence analysis report obtained in step S410, analyze whether it meets one of the following two multiple backup power supply self - closing conditions: 1. Its upper - level power supply is an 110 kV substation, and this 110 kV substation exists in the preliminary consequence analysis report obtained in step S410 and the result is successful backup power supply self - closing; 2. The voltage - loss equipment can be topologically connected to a hot - standby line switch in this substation, and this hot - standby line switch has a topological connection relationship with any line switch that meets the conditions listed in step S405. If either of the above conditions is met, correct the result of this equipment to no voltage loss.

[0138] S412: For the voltage - loss equipment in the preliminary consequence analysis report obtained in step S410, if it does not meet the conditions listed in step S411, further analyze whether it meets the pilot - wire backup power supply self - closing conditions: 1. The 110 kV substation where this voltage - loss equipment is located exists in the pilot - wire backup power supply self - closing maintenance list; 2. Another 110 kV substation paired with this 110 kV substation in the pilot - wire backup power supply self - closing maintenance list has a hot - standby line switch; 3. This hot - standby line switch exists in the power supply scope of other 220 kV operating main transformers except the analyzed main transformer obtained in step S2. If the above conditions are met, correct the result of this equipment to no voltage loss.

[0139] S413: Analyze each 10 kV bus obtained from the topology analysis in the direction of decreasing side in step S2 to determine whether it meets the conditions for the 10 kV sectional backup power supply automatic switching. Specifically, refer to the description in step S409. If the conditions are met, it is determined that after the N - 1 of the main transformer of the analysis object, the 10 kV bus sectional backup power supply automatic switching is successful and there is no voltage loss.

[0140] S414: Summarize the analysis results of steps S412 - S413 to form a consequence report for the N - 1 of the main transformer of the analysis object. After analyzing each object obtained in step S1 one by one, form a risk analysis report for the N - 1 of the 220 kV main transformer in all split - running modes.

[0141] In step S5 mentioned above, conduct a risk analysis for the N - 1 of the main transformer in the case determined to be in a parallel - running mode in step S3, including:

[0142] S501: Pair up multiple 220 kV main transformers in parallel operation as one element, and form a set of all elements and store it in the system.

[0143] S502: Take any 220 kV main transformer in any element in the set obtained in step S501 as the main transformer of the analysis object, and refer to the conditions listed in step S409 to determine whether all 10 kV buses supplied by the main transformer of the analysis object meet the conditions for the 10 kV sectional backup power supply automatic switching.

[0144] S503: Obtain the load value of the remaining 220 kV main transformers paired within the element after the N - 1 of the main transformer of the analysis object. The load value is the sum of the high - voltage side loads of all 220 kV main transformers in the current element minus the load of the 10 kV bus where the main transformer of the analysis object does not meet the sectional backup power supply automatic switching conditions, and then divided by the number of remaining main transformers.

[0145] S504: Compare the load value of the remaining 220 kV main transformers obtained in step S503 with its stability value in the main transformer stability value maintenance table. If it is greater than or equal to the stability value, it is determined that after the N - 1 of the main transformer of the analysis object, it causes the remaining 220 kV main transformer to perform a stability - based load shedding operation.

[0146] S505: For the remaining main transformers that cause load shedding due to stability - based operation obtained in step S504, obtain the line sequence of the load - shedding lines from the stable control cuttable quantity maintenance table.

[0147] S506: In the local database obtained by parsing the automation E - file, set the status of the first N (starting from 1) line switches in the sequence obtained in step S505 to unavailable, and refer to the process of steps S402 - S413 to analyze the voltage loss and backup power supply automatic switching situation of the 110 kV substations or equipment supplied by the above - mentioned line switches after the stability - based operation. However, if the 110 kV substation supplied belongs to the substations in the stable control blocking backup power supply automatic switching maintenance table, no analysis is performed and it is directly determined that the 110 kV substation has a voltage loss.

[0148] S507: According to the analysis result obtained in step S506, calculate the load value of the remaining 220 kV main transformers after removing the first N lines in the stable operation as follows: 1. For the case where the backup power supply automatic switching is successful, if the standby switch closed after the backup power supply automatic switching of the 110 kV substation or equipment supplied by the removed line exists within the power supply range of the remaining 220 kV main transformers obtained in step S2, it has no impact on the remaining main transformer load value; otherwise, evenly distribute the removed load value to each parallel-running main transformer; 2. If the substation or equipment loses voltage, evenly distribute the removed load value to each parallel-running main transformer. After analyzing all N lines one by one, obtain the remaining main transformer load value.

[0149] S508: Judge whether the remaining load value of each operating main transformer obtained in step S507 is less than the rated value in the main transformer stability maintenance table. If it is still greater than or equal to the rated value, after N + 1, repeat steps S506 and S507 until it is less than the rated value or N is equal to the total number of all lines in the line sequence of the removed load, and then stop.

[0150] S509: Summarize the analysis results of steps S502, S504, and S506 - S508 to obtain the N - 1 consequences of the analyzed main transformer. After analyzing all elements in the set obtained in step S501 one by one, form an N - 1 risk analysis report for all 220 kV main transformers in parallel operation modes.

[0151] Step S6: Integrate the results of step S4 and step S5 to form an N - 1 risk analysis report for 220 kV main transformers.

[0152] (5) 220 kV bus N - 1 fault analysis:

[0153] As Figure 7 shown, it is the flowchart of the 220 kV bus N - 1 fault analysis in this embodiment. Step S1: Select the analysis object from the account information in the SCADA system WEB database. The analysis object meets the following conditions: 1. The equipment attribute is the 220 kV substation bus; 2. The voltage level is 220 kV; 3. There is no maintenance sign hung; 4. It is not a power plant bus; 5. It is not a bypass bus.

[0154] Step S2: Analyze the power supply scope of the 220kV bus of the analysis object. Starting from the bus, according to the power flow direction, conduct topological analysis from each transformer high-side switch that is only connected to the bus through several disconnect switches to the middle and low sides of the main transformer. The topological analysis of the low side stops after reaching the 10kV bus of this station; the topological analysis of the middle side is carried out along the path of the middle-side switch - the 110kV bus of this station - the 110kV outgoing line of this station - the bus or line-transformer unit high-side switch of the 110kV substation on the opposite side - the main transformer and 10kV bus of the 110kV substation on the opposite side. For the 110kV buses operating in parallel, the power direction of the bus-tie is not considered during topological analysis; for the 5M bus that is only connected to the 220kV 1M bus through a disconnect switch, no topological analysis is performed. After the topological analysis is completed, all the equipment on the topological path of the 220kV bus of the analysis object and the disconnect switches or switches isolated from other parts of the power grid are saved in the system as the power supply scope of the 220kV bus of the analysis object.

[0155] Step S3: Determine the operating mode of the 220kV bus within this station. If the 220kV bus-tie switch and the disconnect switches on both sides of the substation where the bus is located are in the closed position, it is determined that the station is in a parallel operating mode; if any equipment is not in the closed position, query whether the station is in the 110kV bus-tie backup power supply self-maintenance table. If it exists in the table and the 110kV bus-tie of the station is in hot standby, it is determined that the station is in a parallel operating mode, otherwise it is determined to be in a split operating mode.

[0156] Step S4: Conduct bus N-1 risk analysis for the case determined to be in a split operating mode in Step S3.

[0157] Step S5: Conduct bus N-1 risk analysis for the case determined to be in a parallel operating mode in Step S3.

[0158] Among them, the bus N-1 risk analysis for the case determined to be in a split operating mode in Step S3 specifically includes:

[0159] S401: Take any 110kV substation obtained from the topological analysis in the middle-side direction in Step S2 and the equipment included in the station (110kV bus, main transformer, 10kV bus) as elements, and form a set of all elements and save it in the system.

[0160] S402: Determine whether any substation obtained in Step S401 belongs to the 110kV substations in the user substation maintenance table. If it belongs, directly determine that the station loses voltage after the N-1 of the 220kV bus of the analysis object, and no subsequent analysis is performed.

[0161] S403: For the 110kV substation determined in step S402 as not belonging to the user's substation maintenance table, if any main transformer high-voltage switch contained in the station also exists in the power supply range of other 220kV operating busbars except the analysis object busbar obtained in step S2, then it is determined that the main transformer of the station and the 10kV busbar it supplies and the connected 110kV busbar are all multi-power supply equipment. After analyzing the object bus N-1, the above equipment will not cause voltage loss.

[0162] S404: For any element in the set obtained in step S401, if it does not meet the multi-power supply conditions listed in step S403, and the element contains all the operating equipment of the station (110kV bus, main transformer, 10kV bus), it is determined that the 110kV substation has a short-term voltage loss after the analysis object bus N-1.

[0163] S405: For the 110kV substation that is judged as having a short-term voltage loss in the entire station in step S404, determine whether it meets the following 110kV line standby automatic switching conditions: 1. The station has a hot standby 110kV line switch; 2. The line switch exists in the power supply range of other 220kV operating buses except the analysis object bus obtained in step S2. If so, it is determined that the 110kV line standby automatic switching of the station is successful, and after the analysis object bus N-1, the station does not cause voltage loss.

[0164] S406: For substations that do not meet the conditions listed in step S405, further analyze whether they meet the main transformer standby automatic switch conditions: 1. The station has a hot standby main transformer; 2. The main transformer is in the main transformer standby automatic switch maintenance table; 3. The main transformer high switch exists in the power supply range of other 220kV operating buses except the analysis object bus obtained in step S2. If the above conditions are met, it is determined that after the analysis object bus N-1, the station 110kV main transformer standby automatic switch is successful and does not cause voltage loss.

[0165] S407: For the 110kV substation that is determined as not losing voltage for the entire station for a short time after the main transformer N-1 of the analysis object in step S404, determine whether it meets the 110kV section standby automatic switching conditions: 1. The station has a hot standby 110kV section switch; 2. The section switch exists in the power supply range of other 220kV operating buses except the analysis object bus obtained in step S2. If it meets the conditions, it is determined that the 110kV section standby automatic switching of the station is successful, and after the analysis object bus N-1, no equipment in the station loses voltage.

[0166] S408: For a substation that does not meet the conditions for the 110 kV sectional backup power supply automatic switching, judge one by one whether the 10 kV bus with short-term voltage loss meets the conditions for the main transformer backup power supply automatic switching: 1. The de-energized bus can be topologically connected to the low-voltage side switch of a hot standby main transformer; 2. This hot standby main transformer is in the main transformer backup power supply automatic switching maintenance list; 3. The high-voltage side switch of this hot standby main transformer exists in the power supply scope of other 220 kV operating buses obtained in step S2 except the analyzed object bus. If the above conditions are met, it is determined that after the analyzed object bus undergoes N-1, the main transformer backup power supply automatic switching of the 10 kV bus is successful and no voltage loss is caused.

[0167] S409: For a substation that does not meet the conditions listed in step S408, judge one by one whether the 10 kV bus with short-term voltage loss meets the conditions for the 10 kV sectional backup power supply automatic switching: 1. The de-energized bus can be topologically connected to a hot standby sectional switch; 2. The other bus connected to this hot standby sectional switch is powered by the low-voltage side switch of the main transformer to which it is connected; 3. This hot standby sectional switch exists in the power supply scope of other 220 kV operating buses obtained in step S2 except the analyzed object bus. If the above conditions are met, it is determined that after the analyzed object main transformer undergoes N-1, the sectional backup power supply automatic switching of the 10 kV bus is successful and no voltage loss is caused.

[0168] S411: For the voltage-loss equipment in the preliminary consequence analysis report obtained in step S410, analyze whether it meets one of the following two multiple backup power supply automatic switching conditions: 1. Its upper-level power supply is an 110 kV substation, which exists in the preliminary consequence analysis report obtained in step S410 and the result is successful for the backup power supply automatic switching; 2. This voltage-loss equipment can be topologically connected to a hot standby line switch in this substation, and this hot standby line switch has a topological connection relationship with any line switch that meets the conditions listed in step S405. If either of the above conditions is met, the result of this equipment is corrected to no voltage loss.

[0169] S412: For the voltage-loss equipment in the preliminary consequence analysis report obtained in step S410, if it does not meet the conditions listed in step S411, further analyze whether it meets the conditions for the pilot backup power supply automatic switching: 1. The 110 kV substation where this voltage-loss equipment is located exists in the pilot backup power supply automatic switching maintenance list; 2. Another 110 kV substation paired with this 110 kV substation in the pilot backup power supply automatic switching maintenance list has a hot standby line switch; 3. This hot standby line switch exists in the power supply scope of other 220 kV operating buses obtained in step S2 except the analyzed object bus. If the above conditions are met, the result of this equipment is corrected to no voltage loss.

[0170] S413: Analyze each of the 10 kV busbars obtained from the topology analysis in the direction of the lower side in step S2 to determine whether it meets the conditions for the 10 kV sectional backup power supply automatic switching. Specifically, refer to the description in step S409. If the conditions are met, it is determined that after the N-1 analysis of the busbar of the analysis object, the 10 kV busbar sectional backup power supply automatic switching is successful and no voltage loss is caused.

[0171] S414: Summarize the analysis results of steps S412 - S413 to form a consequence report for the N-1 analysis of the busbar of the analysis object. After analyzing each object obtained in step S1 one by one, form a risk analysis report for the N-1 of the 220 kV busbars in all split operation modes.

[0172] Among them, in step S5, for the case where it is determined to be in a parallel operation mode in step S3, perform a risk analysis of the busbar N-1, which may include:

[0173] S501: Pair the 220 kV main transformers (hereinafter referred to as: object main transformers) within the power supply range of the 220 kV busbar of the analysis object obtained in step S2 with other operating 220 kV main transformers (hereinafter referred to as: other main transformers) in this station, and together with the 220 kV busbar of the analysis object, form an element. All elements are formed into a set and stored in the system.

[0174] S502: After obtaining the N-1 of the 220 kV busbar of the analysis object, obtain the load values of other main transformers within the element. The load value is the sum of the high-side loads of all 220 kV main transformers within the current element divided by the number of other main transformers.

[0175] S503: Compare the load values of other main transformers obtained in step S502 with their stability values in the main transformer stability value maintenance table respectively. If the load value of any one of the other main transformers is greater than or equal to the stability value, it is determined that after the N-1 of the 220 kV busbar of the analysis object, it causes the other main transformers to perform stable operation actions to cut loads.

[0176] S504: For the other main transformers that cause stable operation actions to cut loads obtained in step S503, obtain the line sequence of the loads they cut from the stable control cuttable quantity maintenance table.

[0177] S505: In the local database obtained by parsing the automation E file, set the status of the first N (starting from 1) line switches in the sequence obtained in step S504 to unavailable, and refer to the process of steps S402 - S413 to analyze the voltage loss and backup power supply automatic switching situation of the 110 kV substations or equipment supplied by the above line switches after stable operation actions. However, if the 110 kV substation supplied belongs to the substations in the stable operation lockout backup power supply automatic switching maintenance table, no analysis is performed and it is directly determined that the 110 kV substation has a voltage loss.

[0178] S506: According to the analysis results obtained in step S505, calculate the load values of other main transformers after removing the first N lines of the stable operation actions as follows: 1. For the case where the backup power supply self - switching is successful, if the standby switch closed after the backup power supply self - switching of the 110 kV substation or equipment supplied by the removed line exists within the power supply range of other main transformers in the elements obtained in step S2, there is no impact on the load values of other main transformers; otherwise, evenly distribute the removed load value to other main transformers; 2. If the substation or equipment loses voltage, evenly distribute the removed load value to other main transformers. After analyzing all N lines one by one, obtain the load values of other main transformers.

[0179] S507: Determine whether the load values of other main transformers obtained in step S506 are all less than the set values in the main transformer stability value maintenance table. Otherwise, after N + 1, repeat steps S505 and S506 until it is less than the set value or N is equal to the total number of all lines in the line sequence of the removed load, and then stop.

[0180] S508: Summarize the analysis results of steps S503, S505 - S507 to obtain the N - 1 consequences of the analyzed object bus. After analyzing all elements in the set obtained in step S501 one by one, form an N - 1 risk analysis report for all 220 kV buses in parallel operation modes.

[0181] Step S6: Integrate the results of step S4 and step S5 to form an N - 1 risk analysis report for 220 kV buses.

[0182] Step 104: When the operation mode adjustment is successful, obtain the data at the maximum load moment of the power grid to be analyzed within the preset historical period. According to the data at the maximum load moment and the second topological path, calculate the load rates of 110 kV line switches, transformer high - voltage switches, and 10 kV transformer low - voltage switches, as well as calculate the load rates of 110 kV main transformers and lines, and calculate the load rates of 220 kV substation high - voltage, medium - voltage, and low - voltage switches, and calculate the load rate of 220 kV main transformers. Based on each load rate, analyze whether the main transformers, lines, or equipment are overloaded.

[0183] It should be noted that, as Figure 8 shown, it is the flowchart for analyzing overloaded equipment in this embodiment. The analysis of overloaded equipment can include the following specific steps:

[0184] Step A: Obtain the data at the maximum load moment within a week. Extract the telemetry data of all measurement points in the recent week from the SCADA system WEB database, and obtain the data at the maximum load moment through comparison.

[0185] Step B: Calculate the load rates of the 110 kV line switches, transformer high-side switches, and 10 kV transformer low-side switches. After the successful adjustment of the above operation mode, the 10 kV busbars supplied by each switch can be obtained through recursive query of the topological path. Calculate the load of the switch. At the same time, the limit value of the switch can be obtained by querying the SCADA system WEB database ledger. Calculate the load and load rate of each switch respectively. The calculation formulas for the switch load and load rate are as follows:

[0186] Load rate of 10 kV transformer low-side = (Sum of the currents of all 10 kV feeders under the supplied 10 kV busbar) / Switch limit value;

[0187] Load rate of 110 kV line switch and transformer high-side switch = (Sum of the currents of all 10 kV feeders under the supplied 10 kV busbar) / 11 / Switch limit value;

[0188] Step C: Calculate the load rate of the 110 kV main transformer. According to the topology, the 10 kV busbars supplied by the 110 kV main transformer can be obtained. At the same time, the rated capacity of the main transformer can be obtained by querying the SCADA system WEB database ledger. Calculate the load rate of the 110 kV main transformer. The calculation formula is as follows: Load rate of 110 kV main transformer = (Sum of the currents of all 10 kV feeders under the supplied 10 kV busbar) / 58.5 / Main transformer capacity;

[0189] Step D: Calculate the load rate of the 110 kV line. Calculate the load rate of the 110 kV line. According to the topology, the 110 kV line switch on the 220 kV substation side connected to the 110 kV line can be obtained. Combining with the recursive query of the topological path after the successful adjustment of the above operation mode, the 10 kV busbars supplied by the line switch can be obtained. At the same time, the current-carrying capacity of the line can be obtained by querying the SCADA system WEB database ledger. Calculate the load rate of the 110 kV line according to the formula. The calculation formula is as follows: Load rate of 110 kV line = (Sum of the currents of all 10 kV feeders under the 10 kV busbar supplied by the 110 kV line switch on the 220 kV substation side) / 11 / Current-carrying capacity;

[0190] Step E: Calculate the load rates of the 220 kV substation high-side, medium-side, and low-side switches. The load rate of the 220 kV substation low-side switch can be obtained according to formula ① below; the load rate of the 220 kV substation medium-side switch can be obtained according to formula ②, where the coefficient is set according to the number of medium-side switches that supply the same 110 kV lines. If there are 2 medium-side switches supplying certain 110 kV lines at the same time, the coefficient is 2; the load rate of the 220 kV substation high-side switch can be obtained according to formula ③. The calculation formulas are as follows:

[0191] ① Load rate of 10 kV transformer low-side switch in 220 kV substation = (Sum of the currents of all 10 kV feeders under the supplied 10 kV busbar) / Limit value;

[0192] ② The load rate of the 110 kV transformer medium switch in the 220 kV substation = (the current of the 110 kV line switch supplied) / coefficient / limit value;

[0193] ③ The load rate of the 220 kV transformer high - voltage switch in the 220 kV substation = (the 110 kV current of the 110 kV transformer medium switch supplied + the 110 kV current of the 10 kV transformer low - voltage switch supplied) / 2 / limit value, where the formula for converting the 10 kV current of the 10 kV substation switch to 110 kV current is as follows: 110 kV current = 10 kV current / 11;

[0194] Step F: Calculate the load rate of the 220 kV main transformer. According to the topology, obtain the high - voltage switch connected to the 220 kV main transformer, and at the same time, obtain the rated capacity of the main transformer by querying the SCADA system WEB database ledger. Calculate the load rate of the 220 kV main transformer. The calculation formula is as follows: The load of the 220 kV transformer high - voltage switch = (the 110 kV current of the 110 kV transformer medium switch supplied + the 110 kV current of the 10 kV transformer low - voltage switch supplied) * 11 / 58.5;

[0195] The load rate of the 220 kV main transformer = the load of the high - voltage switch / the rated capacity of the main transformer.

[0196] In this embodiment, based on the current power grid operation mode and power grid operation status, the status of power grid equipment and telemetry data are obtained to form a new power grid power flow diagram. The dispatcher can adjust the power grid operation mode by performing operations such as opening, closing, and setting for maintenance on the status of lines, switches, and disconnectors. After the operation mode adjustment is successful, when key equipment such as the 110 kV main transformer, 110 kV line, 110 kV bus, 220 kV main transformer, and 220 kV bus undergoes an N - 1 fault, the computer system scans to identify the stations, load numbers, user numbers, important users, etc. that lose voltage due to the N - 1 of the equipment, realizing the visualization of real - time power grid risks. At the same time, calculate the load rates of the remaining equipment and key equipment on other power supply paths, and give early warnings for overloaded equipment.

[0197] The above is a power grid risk analysis and early warning method based on sand table deduction provided in the embodiments of the present application. The following is a power grid risk analysis and early warning system based on sand table deduction provided in the embodiments of the present application.

[0198] Please refer to Figure 2 , a power grid risk analysis and early warning system based on sand table deduction provided in the embodiments of the present application, includes:

[0199] An initialization module 201, configured to obtain the real - time operation information of each device in the power grid to be analyzed based on the telemetry data of the SCADAS system, fill the real - time operation information into the blank power flow diagram, and generate a real - time power grid power flow diagram of the power grid to be analyzed;

[0200] An adjustment module 202 is configured to adjust the operation mode of the device to be analyzed on the power grid flow chart, obtain the first topological path before the operation mode adjustment, determine the area range affected by the operation mode adjustment according to the first topological path, determine the second topological path after the adjustment according to the area range, compare and analyze the first topological path and the second topological path, and determine whether the operation mode adjustment is successful;

[0201] A risk analysis module 203 is configured to, when the operation mode adjustment is successful, obtain the line equipment in the area range, perform N-1 fault analysis on the line equipment, and when an N-1 fault occurs in the line equipment, obtain the stations, load numbers, user numbers, and important users that lose voltage due to the N-1 fault, so as to determine the severity level of the fault event, and perform a warning process when the severity level is greater than the preset level; wherein, the line equipment includes: 110 kV main transformers, 110 kV lines, 110 kV buses, 220 kV main transformers, and 220 kV buses;

[0202] A heavy overload analysis module 204 is configured to, when the operation mode adjustment is successful, obtain the maximum load moment data of the power grid to be analyzed in a preset historical period, calculate the load rates of 110 kV line switches, transformer high-side switches, and 10 kV transformer low-side switches according to the maximum load moment data and the second topological path, calculate the load rates of 110 kV main transformers and lines, calculate the load rates of 220 kV substation high-side, medium-side, and low-side switches, calculate the load rate of 220 kV main transformers, and analyze whether the main transformers, lines, or equipment are heavily overloaded based on each load rate.

[0203] Furthermore, in the embodiments of the present application, there is also provided a power grid risk analysis and warning device based on sand table deduction, and the device includes a processor and a memory:

[0204] The memory is configured to store program codes and transmit the program codes to the processor;

[0205] The processor is configured to execute the power grid risk analysis and warning method based on sand table deduction described in the foregoing method embodiments according to the instructions in the program codes.

[0206] Furthermore, in the embodiments of the present application, there is also provided a computer-readable storage medium, and the computer-readable storage medium is configured to store program codes, and the program codes are used to execute the power grid risk analysis and warning method based on sand table deduction described in the foregoing method embodiments.

[0207] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described systems, devices, and units can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0208] In the description of the present application and the above-mentioned drawings, terms such as "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0209] It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects and indicates that three relationships may exist. For example, "A and / or B" may mean: only A exists, only B exists, and both A and B exist at the same time. Among them, A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (one) of the following" or a similar expression means any combination of these items, including any combination of single items (ones) or plural items (ones). For example, at least one (one) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or plural.

[0210] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces, and the indirect coupling or communication connection of devices or units can be in an electrical, mechanical, or other form.

[0211] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0212] In addition, in each embodiment of the present application, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0213] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (English full name: Read-Only Memory, English abbreviation: ROM), random access memories (English full name: Random Access Memory, English abbreviation: RAM), magnetic disks, or optical discs that can store program codes.

[0214] As described above, the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present application.

Claims

1. A power grid risk analysis and early warning method based on sand table deduction, characterized in that Including: S1. Based on the telemetry data of the SCADA system, obtain the real-time operation information of each device in the power grid to be analyzed, fill the real-time operation information into the blank power flow diagram, and generate the real-time power flow diagram of the power grid to be analyzed; S2. Adjust the operation mode of the device to be analyzed on the power flow diagram of the power grid, obtain the first topological path before the operation mode adjustment, determine the affected area range according to the first topological path, determine the second topological path after adjustment according to the area range, and compare and analyze the first topological path and the second topological path to determine whether the operation mode adjustment is successful; S3. When the operation mode adjustment is successful, obtain the line equipment in the area range, conduct N-1 fault analysis on the line equipment. When an N-1 fault occurs in the line equipment, obtain the stations, load numbers, user numbers, and important users that are de-energized due to the N-1 fault, so as to determine the severity level of the fault event. When the severity level is greater than the preset level, warning processing is carried out; wherein, the line equipment includes: 110kV main transformer, 110kV line, 110kV busbar, 220kV main transformer, and 220kV busbar; S4. When the operation mode adjustment is successful, obtain the data at the maximum load moment in the preset historical period of the power grid to be analyzed. According to the maximum load moment data and the second topological path, calculate the load rates of the 110kV class line switches, transformer high-side switches, and 10kV class transformer low-side switches, calculate the load rates of the 110kV main transformers and lines, calculate the load rates of the 220kV substation transformer high-side, medium-side, and low-side switches, and calculate the load rates of the 220kV main transformers. Analyze whether the main transformers, lines, or equipment are overloaded based on each of the load rates; Among them, step S2 specifically includes: S21. Select the device to be analyzed from the power grid account information table, and query the first topological path before the operation mode adjustment of the device to be analyzed; wherein, the device to be analyzed includes: switches, disconnectors, busbars, main transformers, and lines; S22. According to the first topological path, loop through each device to be analyzed, recursively query the affiliated 220kV substations, and take the union of the 220kV substations as the affected boundary to obtain the area range; S23. According to the area range, re-conduct topological analysis on all the main transformers of the 220kV substation to obtain the second topological path after the operation mode adjustment; S24. Compare and analyze the first topological path and the second topological path, and judge whether there are 35kV busbars and 10kV busbars in the first topological path that do not exist in the second topological path. If not, it is determined that the operation mode adjustment is successful. If so, it is determined that the operation mode adjustment fails.

2. The power grid risk analysis and early warning method based on sand table deduction according to claim 1, characterized in that When the line equipment is the 110kV main transformer, the N-1 fault analysis on the line equipment specifically includes: S31. Obtain the basic information and topological path table of the 110kV main transformer, screen out the disconnected main transformer high-side switches according to the basic information and the topological path table, and conduct topological analysis to generate the main transformer high-side switch topological path table; S32. Screen out the bus that meets the preset conditions from the main transformer high-voltage switch topology path table; wherein, the preset conditions include: the bus exists in the topology path table, the voltage level is 10 kV and no maintenance sign is hung. S33. Determine whether the analyzed bus meets any of the bus automatic transfer conditions. If so, execute step S34; otherwise, execute step S35. The bus automatic transfer conditions include:

1. The bus exists in the main transformer high-voltage switch topology path table, and the main transformer to which the high-voltage switch belongs is not the same main transformer as the main transformer to which the analyzed bus belongs; 2. The bus can be topologically connected to a hot standby low-voltage switch; 3. The bus can be topologically connected to a hot standby sectional switch. S34. Determine whether the analyzed bus meets all the conditions of bus series power supply. If so, execute step S35; otherwise, determine that the analyzed bus is in a voltage loss state. The bus series power supply conditions include: there is a superior bus of the same level and the superior bus meets the bus automatic transfer conditions. S35. Obtain the information of the low-voltage switch, main transformer and remaining main transformers to which the analyzed bus belongs, and calculate the load rate of the remaining main transformers. S36. Generate the bus automatic transfer power supply analysis result table of the 110 kV main transformer according to the analysis in steps S33 - S35.

3. The power grid risk analysis and early warning method based on sand table deduction according to claim 1, wherein, The calculation of the load rates of the 110 kV line switch, high-voltage switch and 10 kV low-voltage switch according to the maximum load moment data and the second topology path specifically includes: The load of the 10 kV low-voltage switch is: the sum of the currents of all 10 kV feeders under the 10 kV bus it supplies, divided by the switch limit value. The load rates of the 110 kV line switch and high-voltage switch are: the sum of the currents of all 10 kV feeders under the 10 kV bus it supplies, divided by 11 and then divided by the switch limit value.

4. The power grid risk analysis and early warning method based on sand table deduction according to claim 1, wherein The operation mode adjustment includes: switch load direction adjustment and transferred load calculation. Among them, the switch load direction adjustment specifically includes: When the switch load has positive and negative directions, it is manually set according to the preset rules. The preset rules are: set the 220 kV substation side switch of the 110 kV line to be positive; set the high-voltage switch to be positive and the low-voltage switch to be negative; for the 110 kV line switch, judge through the upper and lower level switches. If the upper load switch is negative, set the switch load to be positive; if the upper load switch is positive, set the switch load to be negative. The transferred load calculation specifically includes: Calculate the loads of all high-voltage, medium-voltage, low-voltage and line switches in the first topology path and the second topology path. Combine the second topology path and recursively query downward to query the 10 kV bus supplied by each switch, and then calculate the switch load by associating all 10 kV feeders under the 10 kV bus.

5. The power grid risk analysis and early warning method based on sand table deduction according to claim 1, characterized in that After step S2, it further includes: When the operation mode adjustment fails, query the 35 kV lines and 10 kV buses that do not exist in the second topology path in the first topology path, take the union to obtain the voltage loss buses.

6. A power grid risk analysis and early warning system based on sand table deduction, characterized in that, Include: An initialization module, configured to obtain real-time operation information of each device in the power grid to be analyzed based on the telemetry data of the SCADA system, fill the real-time operation information into a blank power flow diagram, and generate a real-time power flow diagram of the power grid to be analyzed; An adjustment module, configured to adjust the operation mode of the device to be analyzed on the power flow diagram of the power grid, obtain a first topological path before the operation mode adjustment, determine the affected area range according to the first topological path, determine a second topological path after the adjustment according to the area range, and perform a comparative analysis on the first topological path and the second topological path to determine whether the operation mode adjustment is successful; A risk analysis module, configured to, when the operation mode adjustment is successful, obtain the line equipment in the area range, perform an N-1 fault analysis on the line equipment, when an N-1 fault occurs in the line equipment, obtain the substation, load number, user number, and important users that lose voltage due to the N-1 fault, so as to determine the severity level of the fault event, and perform a warning process when the severity level is greater than a preset level; wherein, the line equipment includes: 110 kV main transformer, 110 kV line, 110 kV busbar, 220 kV main transformer, and 220 kV busbar; A heavy overload analysis module, configured to, when the operation mode adjustment is successful, obtain the data at the maximum load moment in a preset historical period of the power grid to be analyzed, calculate the load rates of the 110 kV line switch, transformer high-voltage switch, and 10 kV transformer low-voltage switch according to the maximum load moment data and the second topological path, calculate the load rates of the 110 kV main transformer and line, calculate the load rates of the 220 kV substation high-voltage, medium-voltage, and low-voltage switches, calculate the load rate of the 220 kV main transformer, and analyze whether the main transformer, line, or equipment is heavily overloaded based on each of the load rates; Wherein, the adjustment module is specifically configured to: Select the device to be analyzed from the power grid account information table, and query the first topological path before the operation mode adjustment of the device to be analyzed; wherein, the device to be analyzed includes: switch, disconnector, busbar, main transformer, and line; Loop through each device to be analyzed according to the first topological path, recursively query the affiliated 220 kV substations, and take the union of the 220 kV substations as the affected boundary to obtain the area range; Perform a topological analysis on all the main transformers of the 220 kV substation according to the area range to obtain a second topological path after the operation mode adjustment; Perform a comparative analysis on the first topological path and the second topological path, and determine whether there are 35 kV busbars and 10 kV busbars in the first topological path that do not exist in the second topological path. If not, it is determined that the operation mode adjustment is successful. If so, it is determined that the operation mode adjustment fails.

7. A power grid risk analysis and early warning device based on sand table deduction, characterized in that, The device includes a processor and a memory: The memory is used to store program codes and transmit the program codes to the processor; The processor is used to execute the power grid risk analysis and warning method based on sand table deduction according to the instructions in the program codes as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program codes, and the program codes are used to execute the method for power grid risk analysis and early warning based on sand table deduction according to any one of claims 1-5.

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