Power grid fault authenticity distinguishing system and method based on protection action event time sequence

Abstract

The invention discloses a power grid fault authenticity distinguishing system and method based on a protection action event time sequence, a comprehensive view is provided by collecting operation information of each protection device, the view can be used for further analyzing a fault, and whether the generated fault is a real fault or not can be preliminarily judged; the correlation value calculation provides a quantitative method, and by comparing the similarity of fault data of different protection actions, whether the protection actions respond to the same fault or not can be judged in an auxiliary manner, so that the logic association between the protection actions can be identified, and whether the protection actions respond to the same fault position or not can be evaluated; and evaluating the correlation between other protection actions and the trigger protection action by using a preset correlation value threshold, and judging whether the fault is a real fault or a suspected fault.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid fault diagnosis, and in particular to a power grid fault authenticity identification system and method based on a protection action event sequence. Background Art

[0002] The information of the parts and the recording files are relatively complete and timely, which lays the foundation for the comprehensive analysis of power grid faults. However, the test action event information during the current protection inspection will interfere with the accurate judgment of power grid faults and affect the accuracy and correctness of power grid fault data processing and comprehensive analysis. In order to realize the practical application of power grid fault analysis, it is necessary to use scientific and technological means to study a method for identifying the authenticity of power grid faults based on the timing of protection action events to solve this problem, improve the correctness and availability of power grid fault analysis, provide accurate power grid analysis information for dispatching and operation, shorten the fault analysis time, improve the power grid fault analysis capability, improve the power grid fault recovery capability, and ensure the stable operation of power grid faults.

[0003] For example, a Chinese patent with publication number CN111835786B discloses a method for coordinated control of distributed power sources. By comparing the stability evaluation index calculated from the actual output power of each area with the preset index value stored in advance, it is determined whether the distributed power sources in each area of ​​the distribution network generate unstable power. This evaluation method is suitable for distributed power active distribution networks with simple structures. However, for transmission lines with complex power transmission, since the evaluation result only shows whether it is stable, it is impossible to further screen the causes of power instability.

[0004] In summary, the following problems exist in the field of comprehensive diagnosis of power grid faults: (1) The test action event information during the current protection inspection will interfere with the accurate judgment of power grid faults and affect the accuracy and correctness of power grid fault data processing and comprehensive analysis; (2) The current evaluation method for the power grid is single, which is to compare the stability evaluation index calculated by the actual output current of each area with the preset index value stored in advance to judge whether the current of the distributed power source in each area of ​​the distribution network is stable. The evaluation result only shows whether it is stable, and it is impossible to further screen the cause of the current instability. Summary of the invention

[0005] Purpose of the invention: The present invention provides a system and method for distinguishing the authenticity of power grid faults based on the timing of protection action events, which can improve the judgment effect of fault authenticity.

[0006] Technical solution: The system for distinguishing the authenticity of power grid faults based on the timing of protection action events described in the present invention comprises: a query module and a protection action management module; the query module is used to monitor the protection device. When the protection device starts the protection action, the protection action is recorded as a triggered protection action, and the protection action information of the triggered protection action is recorded. The protection action information of the triggered protection action includes: the fault interval, the voltage level of the fault interval, and the protection action time. The interval and time window to be queried are generated according to the protection action information, and the protection action information of the triggered protection action, the interval and time window to be queried are transmitted to the protection action management module; the protection action management module is used to generate the trigger information according to the query module. The protection action information of the protection action, the interval to be queried, and the time window are queried. The total accident signal within the time window is queried. If a total accident signal exists, a real fault signal is generated and transmitted to the WEB-side diagnostic display interface. The WEB-side diagnostic display interface displays the information: "The current triggered protection action is caused by a real fault." Otherwise, the protection action of the interval to be queried is queried to obtain a protection action set, and the protection action set is filtered to eliminate the protection actions in the protection action set that are test protection actions within the time window to obtain a filtered protection action set. The filtered protection action set is judged and a judgment fault signal is generated and transmitted to the WEB-side diagnostic display interface, which is displayed accordingly.

[0007] Furthermore, when the voltage level of the fault interval is 220kV or above, the intervals to be queried are the fault interval, other intervals of the fault interval, and related intervals of the fault interval. The start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds.

[0008] When the voltage level of the fault interval is 110kV, the intervals to be queried are other intervals of the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds;

[0009] When the voltage level of the fault interval is 35kV or below, the interval to be queried is the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 160 seconds.

[0010] Furthermore, the other intervals of the fault interval are intervals outside the intervals where the power grid fault occurs under the same plant station, and the related intervals of the fault interval are the intervals where there are two plants stations at both ends of the same line. When the protection devices of the A protection and the B protection of one plant station start the protection action, the A protection and the B protection of the other plant station are located.

[0011] Furthermore, the query module includes: an interval storage unit, a query unit, and a time window generation unit; wherein,

[0012] Interval storage unit: used to store the fault interval, the related interval of the fault interval, and other intervals of the fault interval;

[0013] Query unit: used to use the fault interval that triggers the protection action as an index to search the interval storage unit. When the voltage level of the fault interval is 220kV or above, the related intervals of the fault interval and other intervals of the fault interval are searched, and the fault interval, the related intervals of the fault interval and other intervals of the fault interval are transmitted to the protection action management module; when the voltage level of the fault interval is 110kV, other intervals of the fault interval are searched, and other intervals of the fault interval are transmitted to the protection action management module; when the voltage level of the fault interval is 35kV or below, the fault interval is transmitted to the protection action management module;

[0014] Time window generation unit: used to generate a time window according to the action time of the triggering protection action. The time window generation rule is: when the voltage level of the fault interval is 220kV and above or the voltage level of the fault interval is 110kV, the start time of the time window is the action time of the triggering protection action, and the end time of the time window is the action time of the triggering protection action plus 10 seconds; when the voltage level of the fault interval is 35kV and below, the start time of the time window is the action time of the triggering protection action, and the end time of the time window is the action time of the triggering protection action plus 160 seconds;

[0015] After the time window generation unit generates the time window, the time window generation unit transmits the time window to the protection action management module.

[0016] Furthermore, the protection action management module includes: a protection action storage unit, a filtering unit, and a signal generating unit; wherein,

[0017] Protection action storage unit: used to store protection actions and total accident signals;

[0018] It is used to query the total accident signal within the time window according to the time window transmitted by the time window generation unit. If there is a total accident signal, a real fault signal is generated and transmitted to the WEB-side diagnostic display interface. The WEB-side diagnostic display interface displays the information: "The current triggered protection action is caused by a real fault"; otherwise, it executes: according to the interval to be queried transmitted by the query unit and the time window transmitted by the time window generation unit, query the protection action of the interval to be queried within the time window, obtain the protection action set, and transmit the protection action set to the filtering unit;

[0019] Filtering unit: used for filtering the protection action set transmitted by the protection action storage unit to obtain a filtered protection action set, wherein the filtering rule is: removing the protection actions in the protection action set that are test protection actions within the time window; and transmitting the filtered protection action set to the discrimination unit;

[0020] The discrimination unit is used to make discrimination according to the protection action set after filtering: when the voltage level of the fault interval is 220kV and above, when there are the following two situations, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface, otherwise the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface: Situation 1: the protection action of other intervals and the protection action of the same interval exist in the protection action set after filtering; Situation 2: the protection action of other intervals and the protection action of related intervals exist in the protection action set after filtering;

[0021] When the voltage level of the fault interval is 110kV, the discrimination unit determines whether it is a real fault according to other interval discrimination strategies. If it is a real fault, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface; otherwise, the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface;

[0022] When the voltage level of the fault interval is 35kV and below, the discrimination unit determines whether it is a real fault based on the fault interval expansion discrimination strategy. If it is a real fault, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface. Otherwise, the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface.

[0023] Accordingly, a method for identifying the authenticity of power grid faults based on the timing of protection action events includes the following steps:

[0024] Step 1, the query module monitors the protection device. When the protection device starts the protection action, the protection action is recorded as a triggered protection action, and the protection action information of the triggered protection action is recorded. The protection action information of the triggered protection action includes: fault interval, voltage level of the fault interval, and protection action time. The interval and time window to be queried are generated according to the protection action information, and the protection action information of the triggered protection action, the interval and time window to be queried are transmitted to the protection action management module;

[0025] Step 2: The protection action management module queries the total accident signal within the time window according to the time window transmitted by the time window generation unit. If there is a total accident signal, a real fault signal is generated and transmitted to the WEB-side diagnostic display interface. The WEB-side diagnostic display interface displays the information: "The current protection action is triggered due to a real fault"; otherwise, the protection action management module queries the protection action of the interval to be queried within the time window according to the interval to be queried transmitted by the query module and the time window transmitted by the time window generation unit, and obtains a protection action set;

[0026] Step 3: The protection action management module filters the protection action set, removes the protection actions in the protection action set that are test protection actions within the time window, and obtains a filtered protection action set;

[0027] Step 4: The protection action management module makes a judgment based on the filtered protection action set, generates a fault judgment signal and transmits it to the WEB-side diagnosis display interface.

[0028] Furthermore, in step 1, the query module monitors the protection device and generates the required content to the protection action management module according to the protection action information.

[0029] Step 11, the query module monitors the protection device. When the protection device starts a protection action, the protection action is recorded as a triggered protection action, and the protection action information of the triggered protection action is recorded. The protection action information of the triggered protection action includes: fault interval, voltage level of the fault interval, and protection action time;

[0030] Step 12, the query module determines the voltage level of the fault interval that triggers the protection action; when the voltage level of the fault interval that triggers the protection action is 220kV or above, execute step 13; when the voltage level of the fault interval that triggers the protection action is 110kV, execute step 14; when the voltage level of the fault interval that triggers the protection action is 35kV or below, execute step 15;

[0031] Step 13, the query module generates the intervals and time windows to be queried, the intervals to be queried are the fault intervals, other intervals of the fault intervals, and related intervals of the fault intervals, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds; the query module transmits the intervals and time windows to be queried to the protection action management module, and executes step 16;

[0032] Step 14, the query module generates the interval and time window to be queried, the interval to be queried is other intervals of the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds; the query module transmits the interval and time window to be queried to the protection action management module, and executes step 16;

[0033] Step 15, the query module generates the interval and time window to be queried, the interval to be queried is the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 160 seconds; the query module transmits the interval and time window to be queried to the protection action management module, and executes step 16;

[0034] Step 16. End step 1.

[0035] Furthermore, in step 4, the protection action management module makes a judgment based on the filtered protection action set, generates a judgment fault signal and transmits it to the WEB-side diagnosis display interface, which specifically includes the following steps:

[0036] Step 41, determining the voltage level of the fault interval of the protection action, when the voltage level of the fault interval is 220 kV or above, executing step 42; when the voltage level of the fault interval is 110 kV, executing step 43; when the voltage level of the fault interval is 35 kV or below, executing step 44;

[0037] Step 42, when there are the following two situations, the determination unit generates a real fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current triggering of the protection action is caused by a real fault", otherwise the determination unit generates a suspected fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current triggering of the protection action is caused by a suspected fault": Situation 1: After filtering, the protection action set contains protection actions of other intervals and protection actions of the same interval at the same time; Situation 2: After filtering, the protection action set contains protection actions of other intervals and protection actions of related intervals at the same time, and execute step 45;

[0038] Step 43, the discrimination unit determines whether it is a real fault according to other interval discrimination strategies. If it is a real fault, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface, and the WEB-side diagnostic display interface displays the information: "The current protection action is triggered due to a real fault". Otherwise, the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface, and the WEB-side diagnostic display interface displays the information: "The current protection action is triggered due to a suspected fault", and executes step 45;

[0039] Step 44, the determination unit determines whether it is a real fault according to the fault interval extension determination strategy. If it is a real fault, the determination unit generates a real fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current protection action is triggered due to a real fault". Otherwise, the determination unit generates a suspected fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current protection action is triggered due to a suspected fault", and executes step 45;

[0040] Step 45, end the determination.

[0041] Furthermore, in step 43, other interval discrimination strategies are specifically: calculating the real fault metric value of the protection action set, and the calculation method is as follows:

[0042]

[0043] Among them, C TRUE represents the real fault metric value of the protection action set; P(D→H TURE ) represents the occurrence rate of real faults determined by the protection action set; P(D→H SUSP ) represents the occurrence rate of suspected faults determined by the protection action set; H TURE Indicates a real fault event, H SUSP Indicates a suspected fault event, P(H TURE ) represents the occurrence rate of protection action due to real faults when the voltage level of the fault interval is 110kV; P(H SUSP ) represents the occurrence rate of protection action due to suspected faults when the voltage level of the fault interval is 110kV; D i represents the ith subset of the protection action set D; D represents the protection action set; P(D i ) indicates that in the event of a protection event, the protection action set is D i The incidence rate, P(D i |H TURE ) means that in the event of a real fault, the protection action set is D i The incidence rate; P(D i |H SUSP ) indicates that in the event of a suspected fault, the protection action set is D i The occurrence rate of the protection action set is determined by judging whether the real fault metric value of the protection action set is greater than 1. If it is greater than 1, it is determined to be a real fault; otherwise, it is determined to be a suspected fault.

[0044] Further, in step 44, the fault interval extension discrimination strategy is specifically as follows: querying the protection device fault quantity information of the protection action of the protection action set, generating the protection device fault quantity information of other protection actions including: ranging, fault phase, fault voltage, fault current, zero sequence current; calculating the correlation value between other protection actions of the protection action set and the triggered protection action, wherein the other protection actions are protection actions in the protection action set that do not include the triggered protection action, and the calculation method is as follows:

[0045]

[0046] Among them, GSUM represents the correlation value between other protection actions and triggered protection actions, j represents the number of other protection actions, U represents the set of numbers of other protection actions, A j represents the fault quantity information of the faulty device of the jth other protection action, A0 represents the fault quantity information of the faulty device that triggers the protection action, and N represents the number of other protection actions in the protection action set; it is determined whether the correlation value between other protection actions and the triggered protection action is greater than the correlation value threshold. If it is greater than the correlation value threshold, it is determined to be a real fault; otherwise, it is determined to be a suspected fault; the correlation value threshold is 0.8.

[0047] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) By querying other protection actions within the corresponding time window and combining other protection actions with the triggered protection action, the authenticity of the power grid fault is judged. Compared with the authenticity judgment of a single protection action, the judgment of multiple protection actions can overcome the influence of accidental disturbances on the authenticity judgment and increase the authenticity judgment dimension, thereby improving the judgment effect of the fault authenticity; (2) A filtering method is adopted to filter out the protection actions that are test protection actions within the time window, so that the judgment of the fault authenticity excludes the interference of the test protection action, thereby making the judgment of the fault authenticity more accurate; (3) According to the voltage level of the fault interval, the corresponding judgment method is adopted: when the voltage level of the fault interval that triggers the protection action is 220kV and above, there is A / B double protection and phase difference on both sides of the line. For the same protection, the possibility of real faults is analyzed through the action of four sets of protection, which is more in line with the operating mechanism of protection devices with a voltage level of 220kV and above in the fault interval; when the voltage level of the fault interval is 110kV, since there is only a single set of protection, the disturbance data characteristics of other intervals are used to distinguish between maintenance and faults; by performing effectiveness reasoning, the effectiveness reasoning process is based on the relationship between protection actions, thereby increasing the realistic basis for determining the authenticity of the fault; when the voltage level of the fault interval is 35kV and below, since the grid protection action behavior is more complex, the differential coordination is relatively loose, and it is difficult to capture non-fault interval signals, it is necessary to supplement and expand the analysis time window, strengthen the capture capability of disturbance data, and improve the discrimination accuracy. By adopting corresponding discrimination methods according to the voltage level of the fault interval, the discrimination accuracy can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0049] Figure 2 It is a schematic diagram of the method flow of the present invention. DETAILED DESCRIPTION

[0050] like Figure 1As shown, a power grid fault authenticity identification system based on protection action event sequence includes: being electrically connected to a protection device, when the protection device starts the protection action, triggering the power grid fault authenticity identification system based on the protection action event sequence to distinguish whether the protection action is caused by a real power grid fault, the power grid fault authenticity identification system based on the protection action event sequence includes: a query module, a protection action management module; wherein, the query module: is used to monitor the protection device, when the protection device starts the protection action, the protection action is recorded as a triggered protection action, and the protection action information of the triggered protection action is recorded, the protection action information of the triggered protection action includes: a fault interval, a voltage level of the fault interval, and a protection action time, and the interval and time window to be queried are generated according to the protection action information, and the protection action information and time window of the triggered protection action are transmitted to the protection action management module;

[0051] Among them, when the voltage level of the fault interval is 220kV and above, the intervals to be queried are the fault interval, other intervals of the fault interval, and related intervals of the fault interval. The start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds.

[0052] When the voltage level of the fault interval is 110kV, the intervals to be queried are other intervals of the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds;

[0053] When the voltage level of the fault interval is 35kV or below, the interval to be queried is the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 160 seconds;

[0054] Protection action management module: used to query the total accident signal within the time window according to the protection action information of the triggering protection action transmitted by the query module, the interval to be queried, and the time window. If a total accident signal exists, a real fault signal is generated and transmitted to the WEB diagnostic display interface. The WEB diagnostic display interface displays the information: "The current triggered protection action is caused by a real fault"; otherwise, execute: query the protection actions of the intervals to be queried within the time window, obtain the protection action set, and filter the protection action set to eliminate the protection actions in the protection action set that are test protection actions within the time window to obtain the filtered protection action set, and make a judgment based on the filtered protection action set to generate a judgment fault signal and transmit it to the WEB diagnostic display interface.

[0055] It is worth noting that the other intervals of the fault interval are intervals outside the interval where the power grid fault occurs under the same plant station, and the relevant interval is the interval where there are two plants stations at both ends of the same line. When the protection devices of the A protection set and the B protection set of one plant station start the protection action, the A protection set and the B protection set of the other plant station are located. In the field of relay protection, the A protection set and the B protection set of a plant station are two independent protection sets.

[0056] In the field of relay protection, "fault interval" refers to the "location attribute of the fault occurrence", which is the line section of the protection equipment in the power system, also known as the "protection interval" or "protection range". Any fault within this interval should be detected and isolated by the protection device within the interval.

[0057] Each protection zone usually has its own relay protection device, which is set to cover specific lines or equipment. When a system fault occurs, the corresponding relay protection device will operate to isolate the fault zone and limit the impact of the fault on the power system. The fault interval is an attribute of the protection action.

[0058] The query module includes: an interval storage unit, a query unit, and a time window generation unit;

[0059] Interval storage unit: used to store the fault interval, as well as the related intervals of the fault interval and other intervals;

[0060] Query unit: used to use the fault interval that triggers the protection action as an index to search the interval storage unit. When the voltage level of the fault interval is 220kV or above, the related intervals of the fault interval and other intervals of the fault interval are searched, and the fault interval, the related intervals of the fault interval and other intervals of the fault interval are transmitted to the protection action management module; when the voltage level of the fault interval is 110kV, other intervals of the fault interval are searched, and other intervals of the fault interval are transmitted to the protection action management module; when the voltage level of the fault interval is 35kV or below, the fault interval is transmitted to the protection action management module; the query unit transmits the protection action information that triggers the protection action to the determination unit of the protection action management module;

[0061] Time window generation unit: used to generate a time window according to the action time of the triggering protection action. The time window generation rule is: when the voltage level of the fault interval is 220kV and above or the voltage level of the fault interval is 110kV, the start time of the time window is the action time of the triggering protection action, and the end time of the time window is the action time of the triggering protection action plus 10 seconds; when the voltage level of the fault interval is 35kV and below, the start time of the time window is the action time of the triggering protection action, and the end time of the time window is the action time of the triggering protection action plus 160 seconds;

[0062] After the time window generation unit generates the time window, the time window generation unit transmits the time window to the protection action management module.

[0063] The protection action management module includes: a protection action storage unit, a filtering unit, and a signal generating unit;

[0064] Protection action storage unit: used to store protection actions and total accident signals; the protection action storage unit will perform serial storage according to the time sequence of the protection actions and the total accident signals, combined with the time of reception. The total accident signal is the total accident signal of the monitoring system. The monitoring system is a system set up to monitor the operation status of the power grid. When the monitoring system detects a power grid fault, the monitoring system will start the corresponding program, including sending the total accident signal; the power grid faults that the monitoring system can detect are more obvious, and the types of faults detected are limited. The power grid faults that the monitoring system can monitor are those involving the safety and stability of the power grid.

[0065] The protection actions stored in the protection action storage unit include test protection actions, which are test actions performed by staff on protection equipment during regular protection inspections.

[0066] The protection action stored in the protection action storage unit includes a timestamp of when the protection action occurs;

[0067] The total accident signal stored in the protection action storage unit, including the timestamp of the occurrence of the total accident signal;

[0068] The protection action storage unit is used to query the total accident signal within the time window according to the time window transmitted by the time window generation unit. If there is a total accident signal, a real fault signal is generated and transmitted to the WEB-side diagnostic display interface. The WEB-side diagnostic display interface displays the information: "The current triggered protection action is caused by a real fault"; otherwise, the following is executed: according to the interval to be queried transmitted by the query unit and the time window transmitted by the time window generation unit, the protection action of the interval to be queried within the time window is queried, and a protection action set is obtained, and the protection action set is transmitted to the filtering unit;

[0069] Filtering unit: used for filtering the protection action set transmitted by the protection action storage unit to obtain a filtered protection action set, wherein the filtering rule is: removing the protection actions in the protection action set that are test protection actions within the time window; and transmitting the filtered protection action set to the discrimination unit;

[0070] The discrimination unit is used to make discrimination according to the protection action set after filtering: when the voltage level of the fault interval is 220kV and above, when there are the following two situations, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface, otherwise the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface: Situation 1: the protection action of other intervals and the protection action of the same interval exist in the protection action set after filtering; Situation 2: the protection action of other intervals and the protection action of related intervals exist in the protection action set after filtering;

[0071] When the voltage level of the fault interval is 110kV, the discrimination unit determines whether it is a real fault according to other interval discrimination strategies. If it is a real fault, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface; otherwise, the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface;

[0072] When the voltage level of the fault interval is 35kV and below, the discrimination unit determines whether it is a real fault based on the fault interval expansion discrimination strategy. If it is a real fault, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface. Otherwise, the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface.

[0073] like Figure 2 As shown, a method for distinguishing the authenticity of a power grid fault based on a protection action event sequence is implemented based on a power grid fault authenticity distinguishing system based on a protection action event sequence, and is used to distinguish whether a protection action is caused by a real power grid fault, and includes the following specific steps:

[0074] S1: The query module monitors the protection device. When the protection device starts the protection action, the protection action is recorded as a triggered protection action, and the protection action information of the triggered protection action is recorded. The protection action information of the triggered protection action includes: fault interval, voltage level of the fault interval, and protection action time. The interval and time window to be queried are generated according to the protection action information, and the protection action information of the triggered protection action, the interval and time window to be queried are transmitted to the protection action management module. S1 specifically includes the following steps:

[0075] S101: The query module monitors the protection device. When the protection device starts a protection action, the protection action is recorded as a triggered protection action, and the protection action information of the triggered protection action is recorded. The protection action information of the triggered protection action includes: fault interval, voltage level of the fault interval, and protection action time;

[0076] S102: the query module determines the voltage level of the fault interval that triggers the protection action; when the voltage level of the fault interval that triggers the protection action is 220kV or above, execute S103; when the voltage level of the fault interval that triggers the protection action is 110kV, execute S104; when the voltage level of the fault interval that triggers the protection action is 35kV or below, execute S105;

[0077] S103: The query module generates the intervals and time windows to be queried, the intervals to be queried are the fault intervals, other intervals of the fault intervals, and related intervals of the fault intervals, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds; the query module transmits the intervals and time windows to be queried to the protection action management module, and executes S106;

[0078] S104: The query module generates the interval and time window to be queried, the interval to be queried is other intervals of the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds; the query module transmits the interval and time window to be queried to the protection action management module, and executes S106;

[0079] S105: The query module generates the interval and time window to be queried, the interval to be queried is the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 160 seconds; the query module transmits the interval and time window to be queried to the protection action management module, and executes S106;

[0080] S106: End S1.

[0081] S2: The protection action management module queries the total accident signal within the time window according to the time window transmitted by the query module. If there is a total accident signal, a real fault signal is generated and transmitted to the WEB-side diagnostic display interface. The WEB-side diagnostic display interface displays the information: "The current protection action is triggered due to a real fault"; otherwise, the protection action management module queries the protection action of the interval to be queried within the time window according to the interval to be queried transmitted by the query module and the time window transmitted by the time window generation unit, and obtains a protection action set;

[0082] S3: The protection action management module filters the protection action set, removes the protection actions in the protection action set that are test protection actions within the time window, and obtains a filtered protection action set;

[0083] S4: The protection action management module makes a judgment based on the filtered protection action set, generates a judgment fault signal and transmits it to the WEB-side diagnosis display interface. S4 specifically includes the following steps:

[0084] S401: Determine the voltage level of the fault interval of the protection action. When the voltage level of the fault interval is 220 kV or above, execute S402; when the voltage level of the fault interval is 110 kV, execute S403; when the voltage level of the fault interval is 35 kV or below, execute S404;

[0085] S402: When the following two situations occur, the determination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface, and the WEB-side diagnostic display interface displays the information: "The current triggered protection action is caused by a real fault", otherwise the determination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface, and the WEB-side diagnostic display interface displays the information: "The current triggered protection action is caused by a suspected fault": Situation 1: After filtering, the protection action set contains both protection actions of other intervals and protection actions of the same interval; Situation 2: After filtering, the protection action set contains both protection actions of other intervals and protection actions of related intervals, and S405 is executed;

[0086] S403: The determination unit determines whether it is a real fault according to other interval determination strategies. If it is a real fault, the determination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface, and the WEB-side diagnostic display interface displays the information: "The current protection action is triggered due to a real fault". Otherwise, the determination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface, and the WEB-side diagnostic display interface displays the information: "The current protection action is triggered due to a suspected fault", and executes S405;

[0087] S404: the determination unit determines whether it is a real fault according to the fault interval extension determination strategy. If it is a real fault, the determination unit generates a real fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current protection action is triggered due to a real fault". Otherwise, the determination unit generates a suspected fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current protection action is triggered due to a suspected fault", and executes S405;

[0088] S405: End the determination.

[0089] Among them, other interval discrimination strategies include the following specific steps:

[0090] S40301: Calculate the real fault metric value of the protection action set. The calculation method is as follows:

[0091]

[0092] Among them, C TRUE represents the real fault metric value of the protection action set; P(D→H TURE ) represents the occurrence rate of real faults determined by the protection action set; P(D→H SUSP ) represents the occurrence rate of suspected faults determined by the protection action set; H TURE Indicates a real fault event, H SUSP Indicates a suspected fault event, P(H TURE ) represents the occurrence rate of protection action due to real faults when the voltage level of the fault interval is 110 kV, which is a priori value; P(H SUSP ) represents the occurrence rate of protection action due to suspected faults when the voltage level of the fault interval is 110 kV, which is a priori value; D i represents the ith subset of the protection action set D; D represents the protection action set; P(D i ) indicates that in the event of a protection event, the protection action set is D i The incidence rate, P(D i |H TURE ) means that in the event of a real fault, the protection action set is D i The incidence rate; P(D i |H SUSP ) indicates that in the event of a suspected fault, the protection action set is D i The occurrence rate of action set D is exhausted, so all D i .

[0093] Among them, a real fault event refers to a protection action caused by a real fault when the voltage level of the fault interval is 110kV; a suspected fault event refers to a protection action caused by a suspected fault when the voltage level of the fault interval is 110kV. Suspected faults include: protection actions caused by test protection actions and protection actions caused by disturbances.

[0094] Real faults include: short circuit, grounding, overload, and voltage drop that are not in compliance with normal grid operation;

[0095] Disturbances include: changes in the system steady-state operating point, large-scale power dispatch, operations during equipment maintenance, and communication interference;

[0096] S40302: Determine whether the real fault metric value of the protection action set is greater than 1. If it is greater than 1, it is determined to be a real fault; otherwise, it is determined to be a suspected fault.

[0097] Among them, P(HTURE ) is calculated as follows:

[0098]

[0099] P(H SUSP ) is calculated as follows:

[0100]

[0101] P(D i ) is calculated as follows:

[0102]

[0103] P(D i |H TURE ) is calculated as follows:

[0104]

[0105] P(D i |H SUSP ) is calculated as follows:

[0106]

[0107] The data calculated above all come from the SCADA (Supervisory Control and Data Acquisition) system for power grid monitoring.

[0108] SCADA (Supervisory Control and Data Acquisition) system is an important tool for power grid monitoring, which is used to collect, process and monitor various operation information of the power grid in real time. SCADA system usually contains multiple components, including sensors, remote terminal units (RTUs), communication networks and main computer systems in the central control room. Among them, data storage and management are usually handled by the central database.

[0109] The records of protection actions in the SCADA system database generally include the following specific forms of data:

[0110] 1. Event Log:

[0111] Protection actions are recorded in an event log. Event logs typically contain information such as the timestamp of the event, the event type, the device identifier, and the state change. For example, if an overcurrent protection device is activated, the event log may record the precise time and location of the protection action, as well as the change in the on / off state of the associated circuit breaker caused by the action.

[0112] 2. Alarm and Warning:

[0113] When a protection device is activated, it will generate an alarm, which may be upgraded to an emergency alarm if it is an event that requires immediate response from the operation and maintenance personnel. The alarm information is recorded in a special alarm log, including information such as time, alarm level, device name and event description.

[0114] 3. Measurement and Status Data:

[0115] System parameters and equipment status before and after protection action will also be recorded in the database. These data include voltage, current, power, temperature and other measurement values, as well as status information of switchgear (such as circuit breakers and disconnectors).

[0116] 4. Sequence Event Recorder (SER) data:

[0117] Sequential Events Recorder is a device specially designed to record the sequence of protection actions and related power grid events in detail. SER provides details of the sequence of events, which is very useful for accident analysis and fault diagnosis.

[0118] 5. Trend Analysis Data:

[0119] Some systems perform statistical analysis on parameters such as the frequency, duration, and consequences of protective actions to identify specific trends or potential problems in the grid.

[0120] The data in the database will be organized into tables, records, and fields and managed using standard database management systems such as SQL Server, Oracle, MySQL, etc. Security is also an important consideration in database design, so appropriate access control mechanisms and encryption measures need to be implemented to protect sensitive data.

[0121] In addition to real-time monitoring, the SCADA system's database enables grid operators to analyze historical data to improve system performance, optimize response processes, and enhance future system design. Through accident playback and simulation analysis, the background, causes, and impacts of protection actions can be deeply understood, thereby improving the reliability and resilience of the grid.

[0122] Other interval discrimination strategies distinguish maintenance and faults through the disturbance data characteristics of other intervals; by performing validity reasoning, the validity reasoning process is based on the connection between protection actions, thereby increasing the realistic basis for fault authenticity judgment. In the protection action set, there are multiple protection action combinations (protection action subsets), which are of reference value for authenticity judgment. All protection combinations in the protection action set are enumerated, and the occurrence rates of real faults and suspected faults inferred by the protection combinations are calculated respectively, and finally accumulated, which can make full use of the information value in the protection action set.

[0123] The fault interval extension determination strategy includes the following specific steps:

[0124] S40401: querying the protection device fault quantity information of the protection action of the protection action set, and generating the protection device fault quantity information of other protection actions including: distance measurement, fault phase, fault voltage, fault current, and zero-sequence current;

[0125] S40402: Calculate the correlation values ​​between other protection actions in the protection action set and the triggered protection action, where the other protection actions are protection actions in the protection action set that do not include the triggered protection action, and the calculation method is as follows:

[0126]

[0127] Among them, GSUM represents the correlation value between other protection actions and triggered protection actions, j represents the number of other protection actions, U represents the set of numbers of other protection actions, A j represents the fault quantity information of the fault device of the jth other protection action, A0 represents the fault quantity information of the fault device that triggers the protection action, and N represents the number of other protection actions in the protection action set; A j ∩A0 represents the intersection of the fault quantity information of the fault device of the jth other protection action and the fault quantity information of the fault device that triggers the protection action; A j ∪A0 represents the union of the fault quantity information of the fault device of the jth other protection action and the fault quantity information of the fault device that triggers the protection action; for example: the fault quantity information of the fault device of the first other protection action and the fault quantity information of the fault device that triggers the protection action have the same distance measurement, fault phase difference, fault voltage, and fault current, but different zero-sequence current, and the fault quantity information of the fault device of the other protection action and the fault quantity information of the fault device that triggers the protection action are only distance measurement, fault phase difference, fault voltage, fault current, and zero-sequence current, then A1∩A0 is 4, and A1∪A0 is 6;

[0128] S40403: Determine whether the correlation value between other protection actions and the triggering protection action is greater than the correlation value threshold. If it is greater than the correlation value threshold, it is determined to be a real fault; otherwise, it is determined to be a suspected fault. The correlation value threshold is a fixed value, generally 0.8.

[0129] The present invention provides a comprehensive view by collecting the operation information of each protection device, which can be used for further fault analysis, which helps to preliminarily determine whether the fault is a real fault; the correlation value calculation provides a quantitative method, which can assist in determining whether they are responding to the same fault by comparing the similarity of fault data of different protection actions; this helps to identify the logical relationship between each protection action and evaluate whether they respond to the same fault location; a preset correlation value threshold is used to evaluate the correlation between other protection actions and the triggered protection action to determine whether it is a real fault or a suspected fault.

Claims

1. A power grid fault authenticity identification system based on protection action event sequence, characterized in that: include: Query module and protection action management module; The query module is used to monitor the protection device. When the protection device starts the protection action, the protection action is recorded as a triggered protection action, and the protection action information of the triggered protection action is recorded. The protection action information of the triggered protection action includes: fault interval, voltage level of the fault interval, and protection action time. The interval and time window to be queried are generated according to the protection action information, and the protection action information of the triggered protection action, the interval and time window to be queried are transmitted to the protection action management module; the protection action management module is used to query the time according to the protection action information of the triggered protection action, the interval and time window to be queried transmitted by the query module. The total accident signal in the window, if there is a total accident signal, a real fault signal is generated and transmitted to the WEB-side diagnosis display interface, the WEB-side diagnosis display interface displays the information: "The current triggered protection action is caused by a real fault", otherwise, the protection action of the interval to be queried is queried, and a protection action set is obtained, and the protection action set is filtered, and the protection actions in the protection action set that are test protection actions within the time window are eliminated to obtain a filtered protection action set, and the filtered protection action set is judged according to the filtered protection action set, and a judgment fault signal is generated and transmitted to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface is displayed accordingly.

2. The power grid fault authenticity identification system based on protection action event sequence according to claim 1, characterized in that: When the voltage level of the fault interval is 220kV or above, the intervals to be queried are the fault interval, other intervals of the fault interval, and related intervals of the fault interval. The start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds. When the voltage level of the fault interval is 110kV, the intervals to be queried are other intervals of the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds; When the voltage level of the fault interval is 35kV or below, the interval to be queried is the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 160 seconds.

3. The power grid fault authenticity identification system based on protection action event sequence according to claim 2, characterized in that: The other intervals of the fault interval are intervals outside the intervals where the power grid fault occurs under the same plant station. The related intervals of the fault interval are the intervals where there are two plants stations at both ends of the same line. When the protection devices of the A protection and the B protection of one plant station start the protection action, the A protection and the B protection of the other plant station are located.

4. The power grid fault authenticity identification system based on protection action event sequence according to claim 1, characterized in that: The query module includes: an interval storage unit, a query unit, and a time window generation unit; wherein, Interval storage unit: used to store the fault interval, the related interval of the fault interval, and other intervals of the fault interval; Query unit: used to use the fault interval that triggers the protection action as an index to search the interval storage unit. When the voltage level of the fault interval is 220kV or above, the related intervals of the fault interval and other intervals of the fault interval are searched, and the fault interval, the related intervals of the fault interval and other intervals of the fault interval are transmitted to the protection action management module; when the voltage level of the fault interval is 110kV, other intervals of the fault interval are searched, and other intervals of the fault interval are transmitted to the protection action management module; when the voltage level of the fault interval is 35kV or below, the fault interval is transmitted to the protection action management module; Time window generation unit: used to generate a time window according to the action time of the triggering protection action. The time window generation rule is: when the voltage level of the fault interval is 220kV and above or the voltage level of the fault interval is 110kV, the start time of the time window is the action time of the triggering protection action, and the end time of the time window is the action time of the triggering protection action plus 10 seconds; when the voltage level of the fault interval is 35kV and below, the start time of the time window is the action time of the triggering protection action, and the end time of the time window is the action time of the triggering protection action plus 160 seconds; After the time window generation unit generates the time window, the time window generation unit transmits the time window to the protection action management module.

5. The power grid fault authenticity identification system based on protection action event sequence according to claim 1, characterized in that: The protection action management module includes: a protection action storage unit, a filtering unit, and a signal generating unit; wherein, Protection action storage unit: used to store protection actions and total accident signals; It is used to query the total accident signal within the time window according to the time window transmitted by the time window generation unit. If there is a total accident signal, a real fault signal is generated and transmitted to the WEB-side diagnostic display interface. The WEB-side diagnostic display interface displays the information: "The current triggered protection action is caused by a real fault"; otherwise, it executes: according to the interval to be queried transmitted by the query unit and the time window transmitted by the time window generation unit, query the protection action of the interval to be queried within the time window, obtain the protection action set, and transmit the protection action set to the filtering unit; Filtering unit: used for filtering the protection action set transmitted by the protection action storage unit to obtain a filtered protection action set, wherein the filtering rule is: removing the protection actions in the protection action set that are test protection actions within the time window; and transmitting the filtered protection action set to the discrimination unit; The discrimination unit is used to make discrimination according to the protection action set after filtering: when the voltage level of the fault interval is 220kV and above, when there are the following two situations, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface, otherwise the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface: Situation 1: the protection action of other intervals and the protection action of the same interval exist in the protection action set after filtering; Situation 2: the protection action of other intervals and the protection action of related intervals exist in the protection action set after filtering; When the voltage level of the fault interval is 110kV, the discrimination unit determines whether it is a real fault according to other interval discrimination strategies. If it is a real fault, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface; otherwise, the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface; When the voltage level of the fault interval is 35kV and below, the discrimination unit determines whether it is a real fault based on the fault interval expansion discrimination strategy. If it is a real fault, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface. Otherwise, the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface.

6. A method for identifying the authenticity of a power grid fault based on the timing of protection action events as claimed in claim 1, characterized in that: The steps include: Step 1, the query module monitors the protection device. When the protection device starts the protection action, the protection action is recorded as a triggered protection action, and the protection action information of the triggered protection action is recorded. The protection action information of the triggered protection action includes: fault interval, voltage level of the fault interval, and protection action time. The interval and time window to be queried are generated according to the protection action information, and the protection action information of the triggered protection action, the interval and time window to be queried are transmitted to the protection action management module; Step 2: The protection action management module queries the total accident signal within the time window according to the time window transmitted by the time window generation unit. If there is a total accident signal, a real fault signal is generated and transmitted to the WEB-side diagnostic display interface. The WEB-side diagnostic display interface displays the information: "The current protection action is triggered due to a real fault"; otherwise, the protection action management module queries the protection action of the interval to be queried within the time window according to the interval to be queried transmitted by the query module and the time window transmitted by the time window generation unit, and obtains a protection action set; Step 3: The protection action management module filters the protection action set, removes the protection actions in the protection action set that are test protection actions within the time window, and obtains a filtered protection action set; Step 4: The protection action management module makes a judgment based on the filtered protection action set, generates a fault judgment signal and transmits it to the WEB-side diagnosis display interface.

7. The method for identifying the authenticity of power grid faults based on the timing of protection action events according to claim 6, characterized in that: In step 1, the query module monitors the protection device and generates the required content according to the protection action information to the protection action management module Step 11, the query module monitors the protection device. When the protection device starts a protection action, the protection action is recorded as a triggered protection action, and the protection action information of the triggered protection action is recorded. The protection action information of the triggered protection action includes: fault interval, voltage level of the fault interval, and protection action time; Step 12, the query module determines the voltage level of the fault interval that triggers the protection action; when the voltage level of the fault interval that triggers the protection action is 220kV or above, execute step 13; when the voltage level of the fault interval that triggers the protection action is 110kV, execute step 14; when the voltage level of the fault interval that triggers the protection action is 35kV or below, execute step 15; Step 13, the query module generates the intervals and time windows to be queried, the intervals to be queried are the fault intervals, other intervals of the fault intervals, and related intervals of the fault intervals, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds; the query module transmits the intervals and time windows to be queried to the protection action management module, and executes step 16; Step 14, the query module generates the interval and time window to be queried, the interval to be queried is other intervals of the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 10 seconds; the query module transmits the interval and time window to be queried to the protection action management module, and executes step 16; Step 15, the query module generates the interval and time window to be queried, the interval to be queried is the fault interval, the start time of the time window is the action time of triggering the protection action, and the end time of the time window is the action time of triggering the protection action plus 160 seconds; the query module transmits the interval and time window to be queried to the protection action management module, and executes step 16; Step 16. End step 1.

8. The method for identifying the authenticity of power grid faults based on the timing of protection action events according to claim 6, characterized in that: In step 4, the protection action management module makes a judgment based on the filtered protection action set, generates a judgment fault signal and transmits it to the WEB-side diagnosis display interface, which specifically includes the following steps: Step 41, determining the voltage level of the fault interval of the protection action, when the voltage level of the fault interval is 220 kV or above, executing step 42; when the voltage level of the fault interval is 110 kV, executing step 43; when the voltage level of the fault interval is 35 kV or below, executing step 44; Step 42, when there are the following two situations, the determination unit generates a real fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current triggering of the protection action is caused by a real fault", otherwise the determination unit generates a suspected fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current triggering of the protection action is caused by a suspected fault": Situation 1: After filtering, the protection action set contains both the protection action of other intervals and the protection action of the same interval; Situation 2: After filtering, the protection action set contains both the protection action of other intervals and the protection action of related intervals, and step 45 is executed; Step 43, the discrimination unit determines whether it is a real fault according to other interval discrimination strategies. If it is a real fault, the discrimination unit generates a real fault signal and transmits it to the WEB-side diagnostic display interface, and the WEB-side diagnostic display interface displays the information: "The current protection action is triggered due to a real fault". Otherwise, the discrimination unit generates a suspected fault signal and transmits it to the WEB-side diagnostic display interface, and the WEB-side diagnostic display interface displays the information: "The current protection action is triggered due to a suspected fault", and executes step 45; Step 44, the determination unit determines whether it is a real fault according to the fault interval extension determination strategy. If it is a real fault, the determination unit generates a real fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current protection action is triggered due to a real fault". Otherwise, the determination unit generates a suspected fault signal and transmits it to the WEB-side diagnosis display interface, and the WEB-side diagnosis display interface displays the information: "The current protection action is triggered due to a suspected fault", and executes step 45; Step 45, end the determination.

9. The method for identifying the authenticity of power grid faults based on the timing of protection action events according to claim 8, characterized in that: In step 43, other interval discrimination strategies are specifically: calculating the real fault metric value of the protection action set, and the calculation method is as follows: Among them, C TRUE represents the real fault metric value of the protection action set; P(D→H TURE ) represents the occurrence rate of real faults determined by the protection action set; P(D→H SUSP ) represents the occurrence rate of suspected faults determined by the protection action set; H TURE Indicates a real fault event, H SUSP Indicates a suspected fault event, P(H TURE ) represents the occurrence rate of protection action due to real faults when the voltage level of the fault interval is 110kV; P(H SUSP ) represents the occurrence rate of protection action due to suspected faults when the voltage level of the fault interval is 110kV; D i represents the ith subset of the protection action set D; D represents the protection action set; P(D i ) indicates that in the event of a protection event, the protection action set is D i The incidence rate, P(D i H TURE ) means that in the event of a real fault, the protection action set is D i The incidence rate; P(D i H SUSP ) indicates that in the event of a suspected fault, the protection action set is D i The occurrence rate of the protection action set is determined by judging whether the real fault metric value of the protection action set is greater than 1. If it is greater than 1, it is determined to be a real fault; otherwise, it is determined to be a suspected fault.

10. The method for identifying the authenticity of power grid faults based on the timing of protection action events according to claim 8, characterized in that: In step 44, the fault interval extension discrimination strategy is specifically as follows: query the protection device fault quantity information of the protection action of the protection action set, generate the protection device fault quantity information of other protection actions including: ranging, fault phase, fault voltage, fault current, zero sequence current; calculate the correlation value between other protection actions of the protection action set and the triggered protection action, wherein other protection actions are protection actions in the protection action set that do not include the triggered protection action, and the calculation method is as follows: Among them, G SUM represents the correlation value between other protection actions and the triggered protection action, j represents the number of other protection actions, U represents the set of numbers of other protection actions, A j represents the fault quantity information of the faulty device of the jth other protection action, A0 represents the fault quantity information of the faulty device that triggers the protection action, and N represents the number of other protection actions in the protection action set; it is determined whether the correlation value between other protection actions and the triggered protection action is greater than the correlation value threshold. If it is greater than the correlation value threshold, it is determined to be a real fault; otherwise, it is determined to be a suspected fault; the correlation value threshold is 0.8.

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