Relay protection fault identification and response system

Abstract

The invention relates to the technical field of electrical fault identification and response, in particular to a relay protection fault identification and response system, which comprises a fault propagation path tracking module, a regional fault monitoring module, a misoperation cumulative effect calculation module, a protection level adjustment module and a fault response module. According to the method, based on the triggering sequence and the triggering interval time of the relay protection device, a malfunction propagation mode is extracted, cascade malfunction associated devices are screened, regional power grid fault risk scores are combined, protection level setting is optimized, the malfunction accumulation trend is calculated through malfunction triggering frequency, and high-malfunction devices are identified. The method comprises the following steps: calculating a protection level adjustment factor, optimizing a relay protection level according to a power grid state, enabling a protection strategy to adapt to different operation conditions, calculating power grid operation state parameters in combination with the adjusted protection level, analyzing stability change, optimizing a relay protection response strategy, enabling a relay protection system to have adaptive adjustment capability, and reducing the sudden fault influence range.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical fault identification and response, and in particular to a relay protection fault identification and response system. Background Art

[0002] The field of electrical fault identification and response technology involves monitoring, analyzing and fault detection of the operating status of the power system and its equipment, and responding quickly when an abnormality occurs. It is widely used in scenarios such as substations, power grid dispatching, and industrial distribution systems, aiming to improve the reliability and safety of the power supply system. It mainly includes key links such as fault detection, fault location, protection action triggering, alarm and information transmission, relying on sensors, intelligent algorithms and communication technologies to achieve real-time monitoring and processing of abnormal situations such as short circuits, overloads, and ground faults. With the development of smart grids, this field continues to introduce artificial intelligence, big data analysis and Internet of Things technologies to improve the accuracy and response speed of fault diagnosis.

[0003] Among them, the relay protection fault identification and response system is an intelligent monitoring and emergency response system for relay protection devices. It can automatically detect the operating status of relay protection devices, identify relay protection anomalies caused by false operation, refusal to operate or hardware failure, and respond quickly to reduce power grid accidents caused by protection failure. Its core functions include relay protection status monitoring, fault mode identification, real-time alarm and emergency handling strategy execution, which can effectively improve the stability and safety of the power system.

[0004] Existing technologies mainly rely on single fault detection parameters and lack effective analysis of the propagation mode of relay protection misoperation, which makes it difficult to identify the scope of influence when cascade misoperation occurs, causing multiple devices to misoperate continuously and affecting the stability of the power grid. The short-term fault monitoring method of the regional power grid is based on a fixed threshold, and fails to combine the real-time current impact intensity and voltage fluctuation amplitude for comprehensive evaluation. The judgment of certain high-risk areas is inaccurate, resulting in a mismatch in the relay protection response strategy. The cumulative misoperation assessment is based on the historical misoperation records of a single device, without considering the mutual influence between devices. It is difficult to identify the impact of misoperation accumulation on the overall power grid, resulting in individual devices frequently misoperating without triggering adjustments, and unable to adjust the protection level according to the actual power grid status. In scenarios with large load fluctuations or frequent short-term impacts, the protection action is delayed or mistriggered, affecting the reliability and accuracy of the relay protection system. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings in the prior art and to propose a relay protection fault identification and response system.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A relay protection fault identification and response system comprises: The fault propagation path tracing module collects relay protection device data, records the triggering sequence of relay protection devices, calculates the triggering interval time, analyzes the false operation propagation path, calculates the correlation strength of cascade false operation, determines the cascade false operation and classifies the devices, and generates relay protection false operation propagation data; The regional fault monitoring module obtains regional power grid data based on the relay protection misoperation propagation data, calculates the frequency of regional power grid faults, and generates regional fault risk classification results; The misoperation cumulative effect calculation module calculates the cumulative trend of relay protection misoperation according to the relay protection misoperation propagation data and the regional fault risk classification result, extracts the misoperation triggering frequency, and outputs the relay protection misoperation cumulative intensity data; The protection level adjustment module calculates the protection level adjustment factor of the relay protection device according to the cumulative intensity data of the relay protection misoperation and the regional fault risk classification result, and generates the adjusted relay protection level setting result; The fault response module calculates the regional power grid operation status parameters based on the adjusted relay protection level setting result, dynamically optimizes the relay protection adjustment measures, and generates a power grid relay protection dynamic response plan.

[0007] As a further solution of the present invention, the relay protection false operation propagation data includes relay protection device triggering time record, current mutation rate record, voltage drop rate record, relay protection device triggering sequence, relay protection device triggering interval time, cascade false operation correlation strength, relay protection false operation triggering frequency, false operation cumulative impact value classification result, relay protection false operation propagation path; the regional fault risk classification result includes regional power grid short-term fault triggering statistics, voltage fluctuation amplitude distribution, current impact intensity distribution, fault occurrence frequency per unit time, regional power grid fault risk score, and high-risk area screening result; the relay protection false operation cumulative intensity data includes relay protection false operation cumulative trend, relay protection device false operation triggering frequency statistics, relay protection device false operation cumulative intensity, and false operation high-risk device screening result; the adjusted relay protection level setting result includes relay protection device protection level adjustment factor, relay protection device protection level adjustment judgment result, and relay protection device protection level after adjustment; the power grid relay protection dynamic response plan specifically refers to the adjusted regional power grid operation status parameters, regional power grid operation stability difference analysis record, and relay protection adjustment measure optimization plan.

[0008] As a further solution of the present invention, the fault propagation path tracing module includes a relay protection device triggering data collection submodule, a relay protection malfunction propagation analysis submodule, and a relay protection malfunction impact assessment submodule; The relay protection device triggering data collection submodule collects the current mutation rate and voltage drop rate according to the triggering time of the relay protection device, records the triggering sequence of the relay protection device, calculates the interval time between the triggering of adjacent relay protection devices, and obtains the triggering timing data of the relay protection device; The relay protection malfunction propagation analysis submodule analyzes the relay protection malfunction propagation path according to the relay protection device triggering timing data, and selects the relay protection device whose triggering interval time is less than the set triggering threshold, using the formula: ; Calculate the correlation strength of cascaded false actions , and judge the cascade misoperation to obtain the cascade misoperation propagation sequence, where Represents relay protection device The triggering moment, Represents relay protection device The triggering moment, Represents setting the trigger threshold. Represents the total number of devices in the relay protection device triggering sequence; The relay protection false operation impact assessment submodule calculates the relay protection false operation triggering frequency according to the cascade false operation propagation sequence, classifies the devices according to the false operation cumulative impact value, screens the relay protection devices whose false operation cumulative impact value exceeds the set interval, and generates relay protection false operation propagation data.

[0009] As a further solution of the present invention, the regional fault monitoring module includes a power grid fault data collection submodule, a regional fault risk calculation submodule, and a regional fault risk classification submodule; The power grid fault data collection submodule collects the number of short-term fault triggering times, voltage fluctuation amplitude, and current impact intensity of the regional power grid based on the relay protection malfunction propagation data, calculates the frequency of regional power grid faults per unit time, and obtains regional power grid fault characteristic data; The regional fault risk calculation submodule calls the regional power grid fault characteristic data, and calculates the regional power grid fault risk score based on the fault occurrence rate, voltage stability, and current impact characteristics, using the formula: ; Calculating regional grid failure risk scores , and obtain the regional power grid failure risk assessment results, where: represents the number of failures in the i-th period, Represents the unit time length, represents the voltage value of the i-th period, Represents the reference voltage value, represents the current impulse intensity in the ith period, Represents the total number of calculation periods; The regional fault risk classification submodule screens risk areas with fault risk scores higher than a set risk threshold according to the regional power grid fault risk assessment results, marks them as high-risk areas, and generates regional fault risk classification results.

[0010] As a further solution of the present invention, the misoperation cumulative effect calculation module includes a relay protection misoperation cumulative trend calculation submodule, a relay protection misoperation cumulative intensity calculation submodule, and a relay protection misoperation high risk screening submodule; The relay protection misoperation cumulative trend calculation submodule extracts the relay protection device misoperation trigger frequency based on the relay protection misoperation propagation data and the regional fault risk classification result, calculates the cumulative change of the misoperation frequency in the time dimension, and obtains the relay protection misoperation cumulative trend record; The relay protection misoperation cumulative intensity calculation submodule uses the formula: ; Calculation of cumulative strength of false operation of relay protection devices , get the cumulative intensity data of relay protection misoperation, where, Representative The false trigger frequency of each time period, Represents the unit time interval, Representative The influence of false operation propagation in each time period, Represents the average false operation propagation impact of all time periods, , represents the weight factor of the relay protection device, Represents the total number of relay protection devices, Represents the total number of calculation periods; The relay protection malfunction high-risk screening submodule screens relay protection devices whose malfunction cumulative intensity exceeds a set cumulative threshold based on the relay protection malfunction cumulative intensity data, and generates a list of relay protection malfunction high-risk devices.

[0011] As a further solution of the present invention, the protection level adjustment module includes a relay protection device adjustment factor calculation submodule, a relay protection device adjustment screening submodule, and a relay protection device level setting submodule; The relay protection device adjustment factor calculation submodule adopts the formula based on the cumulative intensity data of relay protection misoperation and the regional fault risk classification result: ; Calculate the protection level adjustment factor of relay protection device , get the relay protection device adjustment factor data, where, Representative The cumulative intensity of false operation in a time period, Represents the unit time length, Representative The regional failure risk score for each time period, represents the median regional failure risk score for all time periods, Represents the time period The voltage fluctuation amplitude of each relay protection device, Represents the reference voltage fluctuation amplitude, represents the weight factor of the relay protection device, Represents the total number of relay protection devices, represents the total number of computation periods, To prevent a small constant with a zero denominator; The relay protection device adjustment screening submodule screens the relay protection devices whose protection level adjustment factors exceed the set adjustment threshold according to the relay protection device adjustment factor data, and obtains a relay protection device adjustment list; The relay protection device level setting submodule adjusts the protection level of the corresponding relay protection device based on the relay protection device adjustment list and generates an adjusted relay protection level setting result.

[0012] As a further solution of the present invention, the fault response module includes a relay protection adjustment submodule, a regional power grid state calculation submodule, and a power grid stability optimization submodule; The relay protection adjustment submodule records the adjusted protection action time, setting value and tripping threshold value based on the adjusted relay protection level setting result, compares the change range of the relay protection action time before and after the adjustment, selects the key relay protection adjustment point, calls the key relay protection adjustment point and matches the protection fault data, calculates the adjusted relay protection response time deviation, and obtains the relay protection response deviation; The regional power grid state calculation submodule is based on the relay protection response deviation, combined with voltage stability, frequency fluctuation range and load transfer efficiency, and compares the change trend of power grid operation parameters before and after adjustment, using the formula: ; Calculate the change in power grid operation status , compare the change range of the operating parameters before and after the adjustment, and obtain the adjusted power grid operating state parameters, among which, represents the voltage value at time i after adjustment, represents the voltage value at time i-1 before adjustment, Represents the relay protection response time at time i, represents the active power at time i after adjustment, represents the reactive power at time i after adjustment, represents the frequency at time i after adjustment, represents the base frequency, Represents the total number of calculation periods; The grid stability optimization submodule calculates the grid stability change trend, screens key operating state change factors, optimizes the relay protection adjustment strategy, adjusts the relay protection level setting, corrects the relay protection tripping threshold, and establishes a grid relay protection dynamic response plan based on the adjusted grid operating state parameters.

[0013] Compared with the prior art, the advantages and positive effects of the present invention are: In the present invention, based on the triggering sequence and triggering interval time of the relay protection device, the false operation propagation mode is extracted, the cascade false operation associated devices are screened, and the protection level setting is optimized in combination with the regional power grid fault risk score. The false operation cumulative trend is calculated through the false operation trigger frequency, the high false operation devices are identified, the protection level adjustment factor is calculated, and the relay protection level is optimized according to the power grid state. The protection strategy is adapted to different operating conditions. The power grid operating state parameters are calculated in combination with the adjusted protection level, the stability change is analyzed, and the relay protection response strategy is optimized. The relay protection system has the ability of adaptive adjustment and the impact range of sudden faults is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a system flow chart of the present invention; Figure 2 This is a flow chart of the fault propagation path tracing module of the present invention; Figure 3 This is a flow chart of the regional fault monitoring module of the present invention; Figure 4 This is a flow chart of the misoperation cumulative effect calculation module of the present invention; Figure 5 This is a flow chart of the protection level adjustment module of the present invention; Figure 6 This is a flow chart of the fault response module of the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0016] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0017] See also Figure 1 , a relay protection fault identification and response system comprises: The fault propagation path tracing module collects the data of relay protection device triggering time, current mutation rate, and voltage drop rate, records the triggering sequence of relay protection devices, calculates the triggering interval time of adjacent relay protection devices, analyzes the relay protection false operation propagation path, screens the devices whose relay protection device triggering interval time is less than the set triggering threshold, calculates the cascade false operation correlation strength, judges the cascade false operation, calculates the relay protection false operation triggering frequency, classifies the devices according to the cumulative impact value of the false operation, screens the relay protection devices whose cumulative impact value of the false operation exceeds the set interval, and generates the relay protection false operation propagation data; The regional fault monitoring module collects the data of short-term fault triggering, voltage fluctuation amplitude, and current impact intensity of the regional power grid based on the relay protection misoperation propagation data, calculates the frequency of regional power grid faults per unit time, and calculates the regional power grid fault risk score based on the fault occurrence rate, voltage stability, and current impact characteristics. It screens high-risk areas where the regional power grid fault risk score is higher than the set risk threshold, and generates regional fault risk classification results; The misoperation cumulative effect calculation module calculates the cumulative trend of relay protection misoperation based on the relay protection misoperation propagation data and the regional fault risk classification results, extracts the misoperation triggering frequency of the relay protection device, calculates the cumulative intensity of the misoperation of the relay protection device, outputs the cumulative intensity data of the misoperation of the relay protection device, and screens the misoperation high-risk devices whose cumulative misoperation of the relay protection device exceeds the set cumulative threshold; The protection level adjustment module calculates the protection level adjustment factor of the relay protection device according to the cumulative intensity data of relay protection false operation and the regional fault risk classification result, selects the relay protection devices whose protection level adjustment factor exceeds the set adjustment threshold, adjusts the protection level of the corresponding relay protection device, and generates the adjusted relay protection level setting result; Based on the adjusted relay protection level setting results, the fault response module calculates the adjusted regional power grid operation status parameters, analyzes the differences in regional power grid operation stability before and after the adjustment, dynamically optimizes the relay protection adjustment measures, and generates a dynamic response plan for the power grid relay protection.

[0018] The relay protection false operation propagation data include the relay protection device triggering time record, current mutation rate record, voltage drop rate record, relay protection device triggering sequence, relay protection device triggering interval time, cascade false operation correlation strength, relay protection false operation triggering frequency, false operation cumulative impact value classification results, and relay protection false operation propagation path; the regional fault risk classification results include the regional power grid short-term fault triggering statistics, voltage fluctuation amplitude distribution, current impact intensity distribution, fault occurrence frequency per unit time, regional power grid fault risk score, and high-risk area screening results; the relay protection false operation cumulative intensity data include the relay protection false operation cumulative trend, relay protection device false operation triggering frequency statistics, relay protection device false operation cumulative intensity, and false operation high-risk device screening results; the adjusted relay protection level setting results include the relay protection device protection level adjustment factor, the relay protection device protection level adjustment judgment result, and the relay protection device protection level after adjustment; the power grid relay protection dynamic response plan specifically refers to the regional power grid operation status parameters after adjustment, the regional power grid operation stability difference analysis record, and the relay protection adjustment measure optimization plan.

[0019] See also Figure 2 ,The fault propagation path tracing module includes a relay protection device triggering data collection submodule, a relay protection misoperation propagation analysis submodule, and a relay protection misoperation impact assessment submodule; The relay protection device triggering data collection submodule collects the current mutation rate and voltage drop rate according to the triggering time of the relay protection device, records the triggering sequence of the relay protection device, calculates the interval time between the triggering of adjacent relay protection devices, and obtains the triggering timing data of the relay protection device; Based on the triggering time of the relay protection device, the triggering timing information of the relay protection device in the system is collected, including the current mutation rate and voltage drop rate of the device when a fault occurs. In practical applications, multiple relay protection devices operate together in the substation. When a component in the system has a short circuit or overload fault, the corresponding relay protection device will be triggered. After the triggering, the triggering time of the relay protection device is recorded. For example, the triggering time of the relay protection device of a certain line is , and the triggering time of the relay protection device of the adjacent line is , by calculating the time difference between the triggering of adjacent devices, the cascade relationship between the devices is determined. The current mutation rate is calculated from the current change before and after the fault occurs. For example, the current before a line fault is After the fault, the current increases to , then the current mutation rate is: ; Similarly, the voltage drop rate is calculated as: ; in, is the voltage before the fault, is the voltage after the fault. If the voltage before the fault is 220kV and drops to 180kV after the fault, the voltage drop rate is: ; All data such as the triggering time, triggering sequence, triggering interval of adjacent relay protection devices, corresponding current mutation rate, voltage drop rate, etc. of all relay protection devices are recorded in the database to form the triggering sequence data of the relay protection device.

[0020] The relay protection false operation propagation analysis submodule analyzes the relay protection false operation propagation path according to the relay protection device triggering timing data, and selects the relay protection device whose triggering interval time is less than the set triggering threshold, using the formula: ; Calculate the correlation strength of cascaded false actions , and judge the cascade misoperation to obtain the cascade misoperation propagation sequence, where Represents relay protection device The triggering moment, Represents relay protection device The triggering moment, Represents setting the trigger threshold. Represents the total number of devices in the relay protection device triggering sequence; The trigger timing data of the relay protection device is called up to analyze the false operation propagation path of each relay protection device. According to the trigger timing of the adjacent relay protection device, it is judged whether the false operation of a certain relay protection device will lead to the false operation of the subsequent device. In practical applications, if the trigger time of relay protection device A on a certain line is 0.15s, and the trigger time of its adjacent device B is 0.22s, the trigger interval time between devices A and B is 0.07s. If the trigger threshold is set to 0.1s, the judgment condition of false operation propagation is met, and the formula is used to calculate the cascade false operation correlation strength.

[0021] set up , , , , , we can calculate: ; If the false operation propagation threshold is set to 0.5, the current calculated value is greater than 0.5, and it is determined that a cascade false operation occurs, and a cascade false operation propagation sequence is obtained.

[0022] The relay protection false operation impact assessment submodule calculates the relay protection false operation triggering frequency according to the cascade false operation propagation sequence, classifies the devices according to the false operation cumulative impact value, screens the relay protection devices whose false operation cumulative impact value exceeds the set interval, and generates relay protection false operation propagation data; Call the cascaded false operation propagation sequence, count the number of false operations of each relay protection device within a certain period of time, and calculate the false operation trigger frequency. For example, if a device has 4 false operations within 10 minutes, the false operation trigger frequency is times / minute, and the cumulative impact value of false operation is calculated based on this value. The impact value calculation method is: ; in, is the cumulative impact value of false operation, is the cascade malfunction correlation strength, is the false action trigger frequency, substitute the above calculated value , times / minute, calculated as: ; The cumulative impact value of false operation is calculated for all relay protection devices, and the false operation classification threshold is set. The cumulative impact value of false operation is set to be low impact if it is less than 0.2, medium impact if it is between 0.2 and 0.5, and high impact if it is greater than 0.5. The calculated value of 0.212 belongs to the medium impact level. The relay protection devices whose impact values ​​exceed the set interval are screened out to generate relay protection false operation propagation data.

[0023] See also Figure 3 ,The regional fault monitoring module includes a power grid fault data collection submodule, a regional fault risk calculation submodule, and a regional fault risk classification submodule; The power grid fault data collection submodule collects the number of short-term fault triggering times, voltage fluctuation amplitude, and current impact intensity of the regional power grid based on the relay protection malfunction propagation data, calculates the frequency of regional power grid faults per unit time, and obtains the regional power grid fault characteristic data; Based on the relay protection false operation propagation data, it is necessary to first confirm the data source and integrity. Usually, the relay protection false operation historical data recorded by the regional power grid monitoring equipment is used, and the data is supplemented in combination with the log of the power dispatching system. In the example, a certain power grid area can be selected to collect all the records of relay protection false operation within a week, and ensure that the data contains information such as trigger time, current and voltage fluctuations, etc. Then, the number of short-term fault triggers in the regional power grid is collected. Short-term faults can be defined as fault events that occur in the power grid for less than 200ms but cause fluctuations in the power grid, such as short-term overvoltage or short-term undervoltage. The number of occurrences of such fault events is extracted through the event records of the monitoring equipment, and the data is sorted. When calculating, the number of short-term fault triggers in a day can be summarized. For example, the number of short-term fault triggers monitored in a certain period of time is 10 times. This data is used as one of the analysis bases. Then, the voltage fluctuation amplitude is collected. The voltage fluctuation amplitude refers to the maximum change amplitude of the voltage before and after the fault occurs, which can be calculated by the formula ; in, represents the steady-state voltage after a fault occurs, Represents the voltage before the fault occurs. If the voltage before the fault is 220kV in a certain area of ​​the power grid, and the voltage drops to 210kV after the fault, the voltage fluctuation amplitude is 10kV. Next, collect the current impact intensity. The current impact intensity refers to the maximum rate of change of the instantaneous current after the fault occurs, that is, the degree of mutation of the current per unit time, which can be calculated as: ; in, represents the pre-fault current, Represents the maximum current after the fault, Represents the measurement time interval. If the current in a certain power grid area is 500A before the fault and rises to 1000A instantly after the fault, and the measurement time interval is 0.1s, then the current impact intensity is: ; Finally, to calculate the frequency of regional power grid faults within a unit time, a certain time window can be used to count the number of fault triggers and normalize them. For example, if the statistical time is set to 1 hour and the number of fault triggers detected within 1 hour is 30 times, the fault frequency is: ; Finally, regional power grid fault characteristic data are obtained, including data sets such as fault triggering times, voltage fluctuation amplitude, current impact intensity, and fault occurrence frequency per unit time.

[0024] The regional fault risk calculation submodule calls the regional power grid fault characteristic data and calculates the regional power grid fault risk score based on the fault occurrence rate, voltage stability, and current impact characteristics. The formula is: ; Calculating regional grid failure risk scores , and obtain the regional power grid failure risk assessment results, where: represents the number of failures in the i-th time period, Represents the unit time length, represents the voltage value of the i-th period, Represents the reference voltage value, represents the current impulse intensity in the ith period, Represents the total number of calculation periods; Call the regional power grid fault characteristic data, analyze the fault occurrence rate, voltage stability, current impact characteristics, and calculate the regional power grid fault risk score. First, the fault occurrence rate calculation method can use the fault number ratio, that is: ; in, represents the failure rate, The cumulative number of failures within the set period. To calculate the duration, if a regional power grid has 120 short-term faults within 24 hours, the fault rate is calculated as: ; Voltage stability analysis requires the calculation of voltage deviation based on historical voltage fluctuation amplitudes. The deviation is calculated as: ; in, Represents the average voltage within the set statistical period. is the standard voltage of the power grid. For example, if the average voltage of a regional power grid in a day is 215 kV and the reference voltage is 220 kV, the voltage deviation is calculated as: ; The current impact characteristic calculation is based on the maximum current mutation rate per unit time. For example, if the calculation period is set to 5 minutes and the maximum current mutation rate within this period is 4000A / s, it can be used for subsequent risk score calculations. Finally, the regional power grid fault risk score is calculated based on the fault occurrence rate, voltage stability, and current impact characteristics. The regional power grid fault risk score is obtained using formula calculations to obtain the regional power grid fault risk assessment value.

[0025] Suppose a power grid area is monitored for three periods, and the data are as follows: , , , , bring into calculation: ; Finally, the calculated regional power grid failure risk assessment value is 10545.0546.

[0026] The regional fault risk classification submodule screens risk areas with fault risk scores higher than the set risk threshold according to the regional power grid fault risk assessment results, marks them as high-risk areas, and generates regional fault risk classification results; The regional power grid fault risk assessment value is called to screen the high-risk areas with fault risk scores higher than the set risk threshold. The risk threshold is set to 10000, and it is judged that 10545.0546>10000. Therefore, the area is divided and marked as a high-risk area, and then the regional fault risk classification result is generated.

[0027] See also Figure 4 ,The false operation cumulative effect calculation module includes a relay protection false operation cumulative trend calculation submodule, a relay protection false operation cumulative intensity calculation submodule, and a relay protection false operation high risk screening submodule; The relay protection misoperation cumulative trend calculation submodule extracts the relay protection device misoperation trigger frequency based on the relay protection misoperation propagation data and the regional fault risk classification results, calculates the cumulative change of the misoperation frequency in the time dimension, and obtains the relay protection misoperation cumulative trend record; Based on the relay protection false operation propagation data and regional fault risk classification results, it is necessary to first determine the false operation propagation of the relay protection device. By monitoring the time distribution of the relay protection false operation in the region, the triggering frequency of the relay protection false operation in different time periods can be obtained. Assuming that the number of false operations of the relay protection device in a certain area within 24 hours is The distribution of false actions in each hour is uneven. The frequency of false actions is higher in some time periods. It is necessary to divide the number of false actions by time period. Suppose the false actions occur between 8:00 and 12:00. times, malfunction occurred between 12:00 and 16:00 times, malfunction occurred between 16:00 and 20:00 times, 20:00-24:00 malfunction occurred times, by calculating the average false trigger frequency per hour , the frequency distribution of false action triggering in different time periods is obtained, so as to analyze the cumulative trend of false action in the time dimension; at the same time, the impact range of false action also needs to be evaluated in combination with the regional fault risk classification results to determine whether there are certain time periods or regions where false action propagation is more intensive. For a specific example, if the false action triggering in area A is 50 times within 24 hours, and the false action triggering in area B is 10 times within 24 hours, then the cumulative trend of false action in area A is obviously faster. It is necessary to further decompose whether there is a propagation relationship between the sources of false action triggering, establish a false action propagation link through data collection, and finally obtain the cumulative trend record of relay protection false action.

[0028] The relay protection misoperation cumulative intensity calculation submodule uses the formula according to the cumulative trend of relay protection misoperation: ; Calculation of cumulative strength of false operation of relay protection devices , get the cumulative intensity data of relay protection misoperation, where, Representative The false trigger frequency of each time period, Represents the unit time interval, Representative The influence of false operation propagation in each time period, Represents the average false operation propagation impact of all time periods, Represents the time period The influence factor of false operation of each relay protection device, represents the weight factor of the relay protection device, Represents the total number of relay protection devices, Represents the total number of calculation periods; Call the cumulative trend record of relay protection misoperation, calculate the cumulative intensity of relay protection device misoperation, set the calculation unit time interval to 4 hours, and the misoperation trigger frequency to 5 times per hour, then Hour, times / hour, times / hour, times / hour, times / hour, and the false operation intensity component is obtained by cumulative calculation. If the false operation propagation influence of relay protection devices in the area within the time period is 1.2, then the regional average influence is Set to 1.2, and obtain the false operation intensity term by calculation, Represents the device weight factor. For the four main relay protection devices, within the set time interval of 4 hours (here a is 1, representing a time period), set , , , , represents the influence of false operation propagation, and the values ​​are 1.5, 1.2, 1.8, and 1.0 respectively. Substituting into the formula, the cumulative term of false operation propagation is calculated as follows: ; Finally, the cumulative strength of false operation is calculated , to obtain the cumulative intensity data of relay protection misoperation. The results show that when When the value is large, the cumulative effect of false operation of the relay protection device in this area is strong, and further measures need to be taken to reduce the false operation propagation path and reduce the false operation triggering frequency.

[0029] The high-risk screening submodule for relay protection misoperation screens relay protection devices whose cumulative misoperation intensity exceeds the set cumulative threshold based on the cumulative intensity data of relay protection misoperation, and generates a list of high-risk devices for relay protection misoperation; According to the cumulative intensity data of relay protection false operation, the relay protection devices whose cumulative intensity of false operation exceeds the set cumulative threshold are screened. The cumulative threshold is set to 2. When the calculated value is greater than the threshold, it is considered that the false operation intensity of the relay protection device is too high and needs to be included in the high-risk list. The above calculation results in a 24-hour false operation cumulative intensity calculation value of 2.26 for the area, which is greater than the cumulative threshold 2. The relay protection devices in the area are included in the false operation high-risk device list. If the false operation cumulative intensity calculation value of another area is 1.95, which is less than the cumulative threshold 2, the area will not be included in the high-risk range. Finally, a list of relay protection false operation high-risk devices is screened out.

[0030] See also Figure 5 , the protection level adjustment module includes a relay protection device adjustment factor calculation submodule, a relay protection device adjustment screening submodule, and a relay protection device level setting submodule; The relay protection device adjustment factor calculation submodule is based on the cumulative intensity data of relay protection misoperation and the regional fault risk classification results, using the formula: ; Calculate the protection level adjustment factor of relay protection device , get the relay protection device adjustment factor data, where, Representative The cumulative intensity of false operation in a time period, Represents the unit time length, Representative The regional failure risk score for each time period, represents the median regional failure risk score for all time periods, Represents the time period The voltage fluctuation amplitude of each relay protection device, Represents the reference voltage fluctuation amplitude, represents the weight factor of the relay protection device, Represents the total number of relay protection devices, represents the total number of computation periods, To prevent a small constant with a zero denominator; The relay protection device adjustment factor calculation submodule is based on the relay protection misoperation cumulative intensity data and the regional fault risk classification results. It is necessary to first extract the misoperation cumulative intensity and regional fault risk score of each relay protection device in different time periods. In practical applications, the relay protection device in a certain power area may reduce the system reliability due to long-term misoperation. For example, the protection device of a substation misoperated 3 times in the past 24 hours, while another substation misoperated only once. At this time, it is necessary to calculate the misoperation cumulative intensity of each device to evaluate its impact. First, record the misoperation cumulative intensity of each relay protection device. For example, the false operation intensity of device A in the past week is The B device is And so on, next, calculate the regional failure risk score within this time period , assuming that the overall fault risk score of a regional power grid in different time periods is , , , calculate its average , ensuring the representativeness of the data distribution, the mean is calculated as: ; Next, calculate the voltage fluctuation amplitude of each device in different time periods , such as a substation voltage fluctuation value in different time periods , , , while determining the reference voltage fluctuation For example, the voltage fluctuation reference value specified by the industry standard is , and calculate the protection level adjustment factor for each device based on these data.

[0031] in, : No. The cumulative intensity of false operation in a certain period of time (e.g., device A has falsely operated 8 times in the past week). : unit time interval (such as 7 days), : No. Regional failure risk score for each time period (e.g. 6.2), : The median regional failure risk score for all time periods (e.g. 6.37), : A small constant (such as 0.01) to prevent the denominator from being zero, : The first The voltage fluctuation amplitude of each relay protection device (e.g. 3.5%, which means that only one relay protection device has voltage fluctuation amplitude in the three time periods), : Reference voltage fluctuation amplitude (such as 3.0%), : Weight factor of relay protection device (e.g. the weight of main transformer protection device is 1.5), : Total number of relay protection devices (e.g. 1 device), : Calculate the total number of time periods (3 time periods).

[0032] Substitute the values ​​into the calculation: ; The protection level adjustment factor of the relay protection device is calculated as follows: , the adjustment threshold is set to 1.0, then the adjustment factor of the device is greater than the threshold and the protection level needs to be adjusted.

[0033] The relay protection device adjustment screening submodule screens the relay protection devices whose protection level adjustment factors exceed the set adjustment threshold according to the relay protection device adjustment factor data, and obtains the relay protection device adjustment list; The relay protection device adjustment screening submodule calls the relay protection device adjustment factor data to screen the relay protection devices whose protection level adjustment factors exceed the set adjustment threshold. In actual applications, the power grid operation and maintenance personnel will set the adjustment threshold. , for example, if , then you need to filter all adjustment factors For devices with a value greater than 0.9, the calculated adjustment factor data is as follows: Table 1 Calculation data

[0034] Adjust the threshold based on ,According to Table 1, all devices with adjustment factors greater than 0.9 are screened out, that is, X1, X2 and X4 need to adjust the protection level, while X3 does not need to be adjusted because its adjustment factor is lower than 0.9. ,In actual operation, the screened devices will be marked and included in the subsequent adjustment process, and a list of devices to be adjusted will be generated to obtain the adjustment list of relay protection devices.

[0035] The relay protection device level setting submodule adjusts the protection level of the corresponding relay protection device based on the relay protection device adjustment list and generates the adjusted relay protection level setting result; The relay protection device level setting submodule calls the relay protection device adjustment list and performs protection level adjustment on the selected relay protection devices. Usually, the protection level adjustment involves changing the set value parameters of the relay protection device, such as the fault current threshold, voltage threshold, delay protection time, etc. In the specific implementation process, it is assumed that devices X1, X2 and X4 need to be adjusted. The adjustment methods include: Adjust the protection setting: Equipment X1 (substation main transformer protection device) Original value: short-circuit current protection setting , delay 0.2s After adjustment: , delay 0.25s Equipment X2 (power transmission line protection device) Original value: voltage lower limit protection , time delay 0.3s After adjustment: , time delay 0.35s Equipment X4 (Sectional switch protection device) Original value: Tripping current threshold

[0036] After adjustment:

[0037] Assume that the current fault current detection value of device X1 is , original protection setting value , the false operation frequency is high, so it is necessary to increase the protection setting to To reduce false operation, calculate the protection level adjustment range: , the adjustment range of the delay protection time is calculated as follows: , calculations show that the protection level will be improved after adjustment, so that the device X1 will trigger protection only when the fault current reaches 1600A, and will trip after a delay of 0.05s. In the power dispatching system, the adjustment parameters can be completed through the remote background system configuration, such as the SCADA system can directly push the new protection setting value to the device, or it can be manually adjusted by the on-site operation and maintenance personnel. All adjustment data will be recorded in the power equipment management system and the adjusted relay protection level setting result will be generated. The final adjusted data will be applied to the relay protection equipment to ensure the rationality of the protection level.

[0038] See also Figure 6 ,The fault response module includes a relay protection adjustment submodule, a regional grid state calculation submodule, and a grid stability optimization submodule; The relay protection adjustment submodule records the adjusted protection action time, setting value and tripping threshold value based on the adjusted relay protection level setting result, compares the change range of the relay protection action time before and after the adjustment, selects the key relay protection adjustment points, calls the key relay protection adjustment points and matches the protection fault data, calculates the adjusted relay protection response time deviation, and obtains the relay protection response deviation; When extracting relay protection parameters based on the relay protection level setting results after adjustment, first obtain the action time, setting value and tripping threshold value of the relay protection device before and after adjustment. The parameters can be extracted through the real-time monitoring data of the dispatching system and the historical records of the protection device. For example, the action time of a certain protection device before adjustment is 0.3s, and after adjustment it is 0.25s, then the action time is reduced by 0.05s. The adjustment range of the setting value and the tripping threshold value can be calculated by comparing the setting values ​​of the protection device in different time periods, and the key relay protection adjustment point with the largest change range is selected, and the historical protection record corresponding to the adjustment point is called. The protection fault data is matched. For example, in the past year, the device tripped 10 times in total. The fault type, fault time and protection device response of each time can be used as the matching basis. By matching the fault data and the adjusted relay protection setting value, the adjusted relay protection response time deviation can be calculated. The calculation method is to subtract the response time before adjustment from the adjusted response time. For example, if the average response time before adjustment is 0.3s and after adjustment is 0.25s, the deviation is -0.05s. This deviation value can be used to evaluate the impact of relay protection adjustment on fault response, and finally obtain the relay protection response deviation.

[0039] The regional power grid status calculation submodule is based on the relay protection response deviation, combined with voltage stability, frequency fluctuation range and load transfer efficiency, and compares the change trend of power grid operation parameters before and after adjustment, using the formula: ; Calculate the change in power grid operation status , compare the change range of the operating parameters before and after the adjustment, and obtain the adjusted power grid operating state parameters, among which, represents the voltage value at time i after adjustment, represents the voltage value at time i-1 before adjustment, Represents the relay protection response time at time i, represents the active power at time i after adjustment, represents the reactive power at time i after adjustment, represents the frequency at time i after adjustment, represents the base frequency, Represents the total number of calculation periods; When calculating the operating parameters of the regional power grid based on the relay protection response deviation, the voltage stability, frequency fluctuation range and load transfer efficiency are first extracted. These parameters can be obtained from the power grid operation monitoring data. For example, the voltage stability can be determined by calculating the deviation between the voltage fluctuation range and the reference voltage. Assuming that the reference voltage at a certain moment is 220kV, and the actual voltage fluctuation range after adjustment is ±5kV, the voltage stability is The frequency fluctuation range can be calculated by comparing the frequency values ​​before and after adjustment. For example, the frequency range in a certain period of time before adjustment is 49.8Hz to 50.2Hz, and after adjustment it is 49.85Hz to 50.15Hz, so the fluctuation range is reduced by 0.05Hz. The load transfer efficiency can be calculated by the ratio of active power to reactive power. Assuming that the active power at a certain moment after adjustment is 500MW and the reactive power is 200Mvar, the load transfer efficiency is Based on the calculation results, the formula is used to obtain the change in the grid operation status, and the change range of the operating parameters before and after the adjustment is compared. For example, if the change in the grid operation status in a certain period of time before the adjustment is 0.8 and after the adjustment is 0.6, it means that the grid operation status tends to be stable, and finally the grid operation status parameters after adjustment are obtained.

[0040] in, represents the voltage value at time i after adjustment, which is 219 kV. represents the voltage value at time i-1 before adjustment, which is 220kV. Represents the relay protection response time at time i, which is 0.25s. represents the active power at time i after adjustment, which is 500MW. represents the reactive power at time i after adjustment, which is 200Mvar, represents the frequency at time i after adjustment, which is 49.85 Hz. represents the reference frequency, which is 50Hz. Represents the number of time slices in the calculation cycle, which is 10.

[0041] Assuming that the data of the 10 time slices are consistent, bring them into the data calculation:

[0042] The results show that the adjusted grid operation status parameters are more stable than those before adjustment and can be used to further optimize the relay protection strategy.

[0043] The grid stability optimization submodule calculates the grid stability change trend based on the adjusted grid operation status parameters, screens key operation status change factors, optimizes the relay protection adjustment strategy, adjusts the relay protection level setting, corrects the relay protection tripping threshold, and establishes a grid relay protection dynamic response plan; When calculating the trend of grid stability changes based on the adjusted grid operation status parameters, first analyze the changes in the adjusted operation parameters and screen the key operating status change factors. For example, by comparing the grid voltage stability, frequency fluctuation range and load transfer efficiency before and after the adjustment, determine which parameters have the most obvious changes. For example, if the voltage stability in a certain period of time before the adjustment is 3%, and it is 2.27% after the adjustment, it means that the voltage fluctuation range has converged. After screening out the key influencing factors, optimize the relay protection adjustment strategy and adjust the relay protection level setting. For example, for areas with a large voltage fluctuation range, the relay protection setting value can be appropriately increased, and for areas with a small frequency fluctuation range, the tripping threshold value can be lowered to optimize the relay protection adjustment strategy. During the execution process, it is necessary to calculate the trend of grid stability changes before and after the adjustment based on the data of the grid operation status change. For example, the grid stability change before the adjustment is 0.8, and after the adjustment is 0.6. Finally, a grid relay protection dynamic response plan is established.

[0044] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A relay protection fault identification and response system, characterized in that: The system comprises: The fault propagation path tracing module collects relay protection device data, records the triggering sequence of relay protection devices, calculates the triggering interval time, analyzes the false operation propagation path, calculates the correlation strength of cascade false operation, determines the cascade false operation and classifies the devices, and generates relay protection false operation propagation data; The regional fault monitoring module obtains regional power grid data based on the relay protection misoperation propagation data, calculates the frequency of regional power grid faults, and generates regional fault risk classification results; The misoperation cumulative effect calculation module calculates the cumulative trend of relay protection misoperation according to the relay protection misoperation propagation data and the regional fault risk classification result, extracts the misoperation triggering frequency, and outputs the relay protection misoperation cumulative intensity data; The protection level adjustment module calculates the protection level adjustment factor of the relay protection device according to the cumulative intensity data of the relay protection misoperation and the regional fault risk classification result, and generates the adjusted relay protection level setting result; The fault response module calculates the regional power grid operation status parameters based on the adjusted relay protection level setting result, dynamically optimizes the relay protection adjustment measures, and generates a power grid relay protection dynamic response plan.

2. The relay protection fault identification and response system according to claim 1, characterized in that: The relay protection misoperation propagation data includes relay protection device triggering time record, current mutation rate record, voltage drop rate record, relay protection device triggering sequence, relay protection device triggering interval time, cascade misoperation correlation strength, relay protection misoperation triggering frequency, misoperation cumulative impact value classification result, and relay protection misoperation propagation path; the regional fault risk classification result includes regional power grid short-term fault triggering statistics, voltage fluctuation amplitude distribution, current impact intensity distribution, fault occurrence frequency per unit time, regional power grid fault risk score, and high-risk area screening results; The relay protection misoperation cumulative intensity data includes the relay protection misoperation cumulative trend, the relay protection device misoperation trigger frequency statistics, the relay protection device misoperation cumulative intensity, and the misoperation high risk device screening results; The adjusted relay protection level setting result includes the protection level adjustment factor of the relay protection device, the protection level adjustment determination result of the relay protection device, and the protection level of the relay protection device after adjustment; The grid relay protection dynamic response plan specifically refers to the adjusted regional grid operation status parameters, regional grid operation stability difference analysis records, and relay protection adjustment measure optimization plan.

3. The relay protection fault identification and response system according to claim 1, characterized in that: The fault propagation path tracing module includes a relay protection device triggering data collection submodule, a relay protection malfunction propagation analysis submodule, and a relay protection malfunction impact assessment submodule; The relay protection device triggering data collection submodule collects the current mutation rate and voltage drop rate according to the triggering time of the relay protection device, records the triggering sequence of the relay protection device, calculates the interval time between the triggering of adjacent relay protection devices, and obtains the triggering timing data of the relay protection device; The relay protection malfunction propagation analysis submodule analyzes the relay protection malfunction propagation path according to the relay protection device triggering timing data, and selects the relay protection device whose triggering interval time is less than the set triggering threshold, using the formula: ； Calculate the correlation strength of cascaded false actions , and judge the cascade misoperation to obtain the cascade misoperation propagation sequence, where Represents relay protection device The triggering moment, Represents relay protection device The triggering moment, Represents setting the trigger threshold. Represents the total number of devices in the relay protection device triggering sequence; The relay protection false operation impact assessment submodule calculates the relay protection false operation triggering frequency according to the cascade false operation propagation sequence, classifies the devices according to the false operation cumulative impact value, screens the relay protection devices whose false operation cumulative impact value exceeds the set interval, and generates relay protection false operation propagation data.

4. The relay protection fault identification and response system according to claim 1, characterized in that: The regional fault monitoring module includes a power grid fault data collection submodule, a regional fault risk calculation submodule, and a regional fault risk classification submodule; The power grid fault data collection submodule collects the number of short-term fault triggering times, voltage fluctuation amplitude, and current impact intensity of the regional power grid based on the relay protection malfunction propagation data, calculates the frequency of regional power grid faults per unit time, and obtains regional power grid fault characteristic data; The regional fault risk calculation submodule calls the regional power grid fault characteristic data, and calculates the regional power grid fault risk score based on the fault occurrence rate, voltage stability, and current impact characteristics, using the formula: ； Calculating regional grid failure risk scores , and obtain the regional power grid failure risk assessment results, where: represents the number of failures in the i-th time period, Represents the unit time length, represents the voltage value of the i-th period, Represents the reference voltage value, represents the current impulse intensity in the ith period, Represents the total number of calculation periods; The regional fault risk classification submodule screens risk areas with fault risk scores higher than a set risk threshold according to the regional power grid fault risk assessment results, marks them as high-risk areas, and generates regional fault risk classification results.

5. The relay protection fault identification and response system according to claim 1, characterized in that: The misoperation cumulative effect calculation module includes a relay protection misoperation cumulative trend calculation submodule, a relay protection misoperation cumulative intensity calculation submodule, and a relay protection misoperation high risk screening submodule; The relay protection misoperation cumulative trend calculation submodule extracts the relay protection device misoperation trigger frequency based on the relay protection misoperation propagation data and the regional fault risk classification result, calculates the cumulative change of the misoperation frequency in the time dimension, and obtains the relay protection misoperation cumulative trend record; The relay protection misoperation cumulative intensity calculation submodule uses the formula: ； Calculation of cumulative strength of false operation of relay protection devices , get the cumulative intensity data of relay protection misoperation, where, Representative The false trigger frequency of each time period, Represents the unit time interval, Representative The influence of false operation propagation in each time period, Represents the average false operation propagation impact of all time periods, Represents the time period The influence factor of false operation of each relay protection device, represents the weight factor of the relay protection device, Represents the total number of relay protection devices, Represents the total number of calculation periods; The relay protection malfunction high-risk screening submodule screens relay protection devices whose malfunction cumulative intensity exceeds a set cumulative threshold based on the relay protection malfunction cumulative intensity data, and generates a list of relay protection malfunction high-risk devices.

6. The relay protection fault identification and response system according to claim 1, characterized in that: The protection level adjustment module includes a relay protection device adjustment factor calculation submodule, a relay protection device adjustment screening submodule, and a relay protection device level setting submodule; The relay protection device adjustment factor calculation submodule adopts the formula based on the cumulative intensity data of relay protection misoperation and the regional fault risk classification result: ； Calculate the protection level adjustment factor of relay protection device , get the relay protection device adjustment factor data, where, Representative The cumulative intensity of false operation in a time period, Represents the unit time length, Representative The regional failure risk score for each time period, represents the median regional failure risk score for all time periods, Represents the time period The voltage fluctuation amplitude of each relay protection device, Represents the reference voltage fluctuation amplitude, represents the weight factor of the relay protection device, Represents the total number of relay protection devices, represents the total number of computation periods, To prevent a small constant with a zero denominator; The relay protection device adjustment screening submodule screens the relay protection devices whose protection level adjustment factors exceed the set adjustment threshold according to the relay protection device adjustment factor data, and obtains a relay protection device adjustment list; The relay protection device level setting submodule adjusts the protection level of the corresponding relay protection device based on the relay protection device adjustment list and generates an adjusted relay protection level setting result.

7. The relay protection fault identification and response system according to claim 1, characterized in that: The fault response module includes a relay protection adjustment submodule, a regional power grid state calculation submodule, and a power grid stability optimization submodule; The relay protection adjustment submodule records the adjusted protection action time, setting value and tripping threshold value based on the adjusted relay protection level setting result, compares the change range of the relay protection action time before and after the adjustment, selects the key relay protection adjustment point, calls the key relay protection adjustment point and matches the protection fault data, calculates the adjusted relay protection response time deviation, and obtains the relay protection response deviation; The regional power grid state calculation submodule is based on the relay protection response deviation, combined with voltage stability, frequency fluctuation range and load transfer efficiency, and compares the change trend of power grid operation parameters before and after adjustment, using the formula: ； Calculate the change in power grid operation status , compare the change range of the operating parameters before and after the adjustment, and obtain the adjusted power grid operating state parameters, among which, represents the voltage value at time i after adjustment, represents the voltage value at time i-1 before adjustment, Represents the relay protection response time at time i, represents the active power at time i after adjustment, represents the reactive power at time i after adjustment, represents the frequency at time i after adjustment, represents the base frequency, Represents the total number of calculation periods; The grid stability optimization submodule calculates the grid stability change trend, screens key operating state change factors, optimizes the relay protection adjustment strategy, adjusts the relay protection level setting, corrects the relay protection tripping threshold, and establishes a grid relay protection dynamic response plan based on the adjusted grid operating state parameters.

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