A Predictive Maintenance Method and System for Relay Protection Equipment

Abstract

The present invention relates to the technical field of predictive maintenance, and specifically to a method and system for predictive maintenance of relay protection equipment, which includes the following steps: calculating the change trend of each operating parameter within each time window based on the operating parameters of the relay equipment to obtain the change rate of the operating state of the relay equipment. In the present invention, by refining the operating trends at different time scales, the change rate of the operating state is accurately extracted to quantify the health state of the relay equipment, and the health score decay rate is calculated in combination with the equipment aging degree, contact wear degree, and relay operation times, so as to measure the decline rate of the health degree, which can achieve accurate judgment of the equipment maintenance requirements, calculate the maintenance task priority in combination with the equipment importance weight, make the maintenance resource allocation more targeted, quantify the equipment load fluctuation situation, and dynamically adjust the maintenance cycle according to the set threshold to match the equipment load change trend, avoiding the problems of over-maintenance or under-maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of predictive maintenance, and particularly to a method and system for predictive maintenance of relay protection equipment. Background Art

[0002] The technical field of predictive maintenance includes maintenance methods based on analysis of equipment operation data, condition monitoring, and fault prediction. The core content of this technical field involves using sensing acquisition, anomaly detection, and trend analysis techniques to evaluate the health status of equipment, and predicting possible future faults based on historical data and models to optimize the maintenance plan. The overall application of predictive maintenance technology includes acquisition and storage of equipment monitoring data, establishment of a health status evaluation model, application of anomaly detection algorithms, implementation of life prediction methods, and automatic optimization of maintenance plans. This field usually combines methods such as statistical analysis, machine learning models, and fault tree analysis to reduce unplanned equipment downtime and optimize the allocation of maintenance resources.

[0003] Among them, the method for predictive maintenance of relay protection equipment refers to monitoring the health status of relay protection equipment and formulating maintenance strategies based on the operating parameters of relay protection equipment, relay protection action records, and fault historical data through multi-dimensional feature analysis, state evaluation model calculation, and trend prediction methods. The key technical matters for this method regarding relay protection equipment include operating state monitoring, fault prediction analysis, and maintenance strategy optimization. Operating state monitoring uses parameters such as current, voltage, frequency, and phase angle of relay protection equipment, and evaluates the health status of the equipment through time series analysis and feature extraction methods. Fault prediction analysis uses historical fault records, relay action data, and equipment aging trends to achieve short-term and long-term fault trend prediction based on probability statistics methods or model-based diagnostic methods. Maintenance strategy optimization combines equipment health assessment data with maintenance resource allocation constraints, and uses decision optimization models or heuristic algorithms to formulate the optimal maintenance scheduling plan.

[0004] Traditional maintenance methods mainly rely on equipment operation data for condition monitoring and fault prediction, without distinguishing state changes on different time scales, making it difficult to distinguish short-term fluctuations and long-term deterioration of equipment, resulting in a lack of pertinence in maintenance strategies, weak response ability to real-time changes in equipment health, and easy neglect of stage changes in health status, thus affecting the accuracy of maintenance timing. Maintenance strategy optimization mainly relies on equipment health assessment data, but does not fully consider the importance weight of equipment, load fluctuations, and the change trend of equipment operating state, leading to unbalanced allocation of maintenance resources, difficulty in optimizing the maintenance plan according to load fluctuations, resulting in a fixed maintenance cycle for equipment under high-load or low-load conditions, and being unable to adapt to actual working conditions. Summary of the Invention

[0005] The object of the present invention is to solve the disadvantages existing in the prior art, and to propose a predictive maintenance method and system for relay protection equipment.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A predictive maintenance method for relay protection equipment, comprising the following steps:

[0007] S1: Based on the operating parameters of the relay equipment, calculate the change trend of each operating parameter within each time window to obtain the change rate of the operating state of the relay equipment;

[0008] S2: Based on the change rate of the operating state of the relay equipment, calculate the health score of the relay equipment, screen the equipment with a health score lower than the health threshold, calculate the attenuation rate of the health score per unit time, and obtain the health decline rate of the relay equipment;

[0009] S3: Based on the health decline rate of the relay equipment, determine whether maintenance is required for the equipment, combine the importance weight parameters of the equipment, calculate the priority of the equipment maintenance task, and obtain the maintenance task priority list;

[0010] S4: Based on the maintenance task priority list, obtain the load current, opening times and current-carrying time of the relay equipment, calculate the mean value and standard deviation of the load change rate, judge the load fluctuation situation, adjust the maintenance period, and obtain the maintenance adjustment amount of the relay equipment;

[0011] S5: Based on the maintenance adjustment amount of the relay equipment and the maintenance task priority list, calculate the required number of maintenance personnel and the required spare parts reserve for the relay protection relay, and adjust the maintenance time window to obtain the relay equipment maintenance resource allocation information.

[0012] As a further solution of the present invention, the change rate of the operating state of the relay equipment includes the coil current change rate, the contact resistance increment rate, the tripping current threshold fluctuation trend and the protection logic trigger frequency change value. The health decline rate of the relay equipment is specifically the health score attenuation rate, the coil aging trend value, the contact wear growth amount and the abnormal action ratio of the relay. The maintenance task priority list includes the maintenance task sorting coefficient, the fault impact level coefficient, the health decline evaluation value and the task execution urgency. The maintenance adjustment amount of the relay equipment is specifically the maintenance interval correction value, the load fluctuation influence coefficient, the maintenance plan adjustment time and the equipment maintenance level change information. The relay equipment maintenance resource allocation information includes the required number of maintenance personnel, the required spare parts reserve, the maintenance time window and the task execution work order number.

[0013] As a further solution of the present invention, the specific steps for obtaining the change rate of the operating state of the relay equipment are as follows:

[0014] S111: Based on the operating parameters of the relay equipment, obtain the coil current, contact resistance, tripping current threshold, and the number of times of relay protection logic triggering. Set short-term, medium-term, and long-term time windows, calculate the data change rate of each operating parameter within each time window, using the formula:

[0015] ;

[0016] Calculate the change rate of the operating parameters within each time window to obtain the operating parameter change information;

[0017] Among them, represents the change rate of the th operating parameter within the time , represents the th operating parameter at the time , represents the th operating parameter at the time , represents the time length of the time window ;

[0018] S112: Invoke the operating parameter change information, calculate the change trend of each parameter within different time windows, and use linear regression to fit the slope of the trend change to obtain the operating state change slope;

[0019] S113: Invoke the operating state change slope, filter the operating parameters whose change trend exceeds the preset change threshold according to the mean and variance of the change rate of each parameter, and calculate the proportion of the change rate of the parameter to obtain the operating state change rate of the relay equipment.

[0020] As a further solution of the present invention, the step of obtaining the decline rate of the health of the relay equipment is specifically as follows:

[0021] S211: Based on the operating state change rate of the relay equipment, use the formula:

[0022] ;

[0023] Calculate the health score to obtain the health information of the relay equipment;

[0024] Among them, represents the health score, represents the current change rate of the th operating parameter, represents the influence weight of the th operating parameter, represents the total number of operating parameters;

[0025] S212: Call the health information of the relay equipment, set a health threshold, filter the equipment with a health score lower than the health threshold, obtain the coil aging degree, contact wear degree and relay operation times information of the equipment, and obtain a set of equipment with a health lower than the threshold;

[0026] S213: Call the set of equipment with a health lower than the threshold, calculate the attenuation rate of the health score per unit time, and obtain the health decline rate of the relay equipment.

[0027] As a further solution of the present invention, the step of obtaining the maintenance task priority list is specifically as follows:

[0028] S311: Based on the health decline rate of the relay equipment, compare it with a preset attenuation threshold, judge whether the equipment needs to be maintained, filter the equipment with a health decline rate higher than the attenuation threshold, and obtain a set of equipment to be maintained;

[0029] S312: Call the set of equipment to be maintained, combine the equipment importance weight parameter, and use the formula:

[0030] ;

[0031] Calculate the maintenance task priority of each piece of equipment;

[0032] Wherein, represents the equipment maintenance task priority, represents the health decline rate, represents the equipment importance weight, represents the change amount of the health score, represents the time period since the equipment was last maintained;

[0033] S313: Call the maintenance task priority of the equipment, sort the equipment to be maintained according to the priority, and obtain the maintenance task priority list.

[0034] As a further solution of the present invention, the step of obtaining the maintenance adjustment amount of the relay equipment is specifically as follows:

[0035] S411: Based on the maintenance task priority column, obtain the load current, opening and closing times and current-carrying time of the relay equipment, and calculate the mean and standard deviation of the load change rate to obtain the load change rate statistical value;

[0036] S412: Call the load change rate statistical value, judge the load fluctuation situation, compare it with a preset load fluctuation threshold, determine whether the maintenance cycle needs to be adjusted, and use the formula:

[0037] ;

[0038] Calculate the adjusted maintenance cycle;

[0039] Wherein, represents the adjusted maintenance cycle, represents the current maintenance cycle, represents the standard deviation of the load change rate, represents the mean value of the load change rate;

[0040] S413: Invoke the adjusted maintenance cycle, calculate the required adjustment amount according to the current maintenance cycle, and obtain the relay equipment maintenance adjustment amount.

[0041] As a further solution of the present invention, the step of obtaining the relay equipment maintenance resource allocation information is specifically as follows:

[0042] S511: Based on the relay equipment maintenance adjustment amount and the maintenance task priority list, calculate the required number of maintenance personnel for the relay protection relay, obtain the number of maintenance tasks, the standard working hours per task, and the available working hour resources, and obtain the maintenance personnel demand information;

[0043] S512: Invoke the maintenance personnel demand information, combine it with the spare part consumption situation of the equipment maintenance task, and combine the current inventory status and the safety reserve threshold, and use the formula:

[0044] ;

[0045] Calculate the spare part reserve demand;

[0046] Wherein, represents the spare part reserve demand, represents the th spare part consumption rate of the equipment, represents the th adjusted maintenance cycle of the equipment, represents the th supply rate of the replenishable spare parts per unit time of the equipment, represents the current inventory, represents the total number of equipment;

[0047] S513: Invoke the spare part reserve demand, combine it with the demand for maintenance personnel, adjust the maintenance time window, and optimize the task allocation to obtain the relay equipment maintenance resource allocation information.

[0048] A relay protection equipment predictive maintenance system, the relay protection equipment predictive maintenance system is used to execute the above-mentioned relay protection equipment predictive maintenance method, and the system includes:

[0049] The operating status analysis module calculates the change trend of each operating parameter within each time window based on the operating parameters of the relay equipment, and obtains the change rate of the operating status of the relay equipment.

[0050] The health degree change analysis module filters out the equipment with a health degree score lower than the health degree threshold based on the change rate of the operating status of the relay equipment, calculates the decay rate of the health score per unit time, and obtains the decline rate of the health degree of the relay equipment.

[0051] The maintenance task ranking module determines whether maintenance is required for the equipment based on the decline rate of the health degree of the relay equipment, calculates the priority of the equipment maintenance task, and obtains the maintenance task priority list.

[0052] The maintenance cycle adjustment module calculates the mean value and standard deviation of the load change rate based on the maintenance task priority list, judges the load fluctuation situation, adjusts the maintenance cycle, and obtains the maintenance adjustment amount of the relay equipment.

[0053] The maintenance resource scheduling module calculates the demand for maintenance personnel and the demand for spare part reserves of the relay protection relay based on the maintenance adjustment amount of the relay equipment and the maintenance task priority list, and adjusts the maintenance time window to obtain the maintenance resource allocation information of the relay equipment.

[0054] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0055] In the present invention, by refining the operating trends at different time scales, accurately extracting the change rate of the operating status to quantify the health status of the relay equipment, through the calculation of the health degree score and the screening of the health degree threshold, potential problems can be identified before significant failures of the equipment occur, and the decay rate of the health score is calculated in combination with the equipment aging degree, contact wear degree and relay operation times, so as to measure the decline rate of the health degree, making the evaluation of the equipment status deterioration more refined. By comparing the decline rate of the health degree with the preset decay threshold, the accurate judgment of the equipment maintenance requirements can be realized, and the maintenance task priority is calculated in combination with the equipment importance weight, making the maintenance resource allocation more targeted. By introducing the load current, breaking times and current-carrying time to calculate the mean value and standard deviation of the load change rate, the load fluctuation situation of the equipment can be quantified, and the maintenance cycle is dynamically adjusted according to the set threshold to match the load change trend of the equipment. By calculating the demand for maintenance personnel and the demand for spare part reserves based on the maintenance adjustment amount and the maintenance task priority, and optimizing the maintenance resource allocation in combination with the inventory status, the maintenance strategy can be dynamically optimized with the operation status of the equipment, improving the resource utilization efficiency and avoiding the problems of over-maintenance or under-maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a schematic flow chart of the method of the present invention;

[0057] Figure 2Flow chart for obtaining the change rate of the operating state of relay equipment in the present invention;

[0058] Figure 3 Flow chart for obtaining the decline rate of the health of relay equipment in the present invention;

[0059] Figure 4 Flow chart for obtaining the list of maintenance task priorities in the present invention;

[0060] Figure 5 Flow chart for obtaining the maintenance adjustment amount of relay equipment in the present invention;

[0061] Figure 6 Flow chart for obtaining the maintenance resource allocation information of relay equipment in the present invention. Detailed implementation manners

[0062] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to 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 used to limit the present invention.

[0063] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying 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 thus should not be construed as limiting the present invention. In addition, in the description of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0064] Embodiment 1

[0065] Please refer to Figure 1 , the present invention provides a technical solution: a predictive maintenance method for relay protection equipment, including the following steps:

[0066] S1: Based on the operating parameters of relay equipment, the operating parameters include coil current, contact resistance, trip current threshold, and the number of times of relay protection logic triggering, set short-term, medium-term, and long-term time windows, and calculate the change trends of each operating parameter within each time window respectively to obtain the change rate of the operating state of relay equipment;

[0067] S2: Calculate the health score of the relay equipment based on the change rate of the operating state of the relay equipment, set a health threshold, screen the equipment with a health score lower than the health threshold, call the data of the coil aging degree, contact wear degree and relay operation times of the equipment, calculate the attenuation rate of the health score per unit time, and obtain the health decline rate of the relay equipment;

[0068] S3: Compare the health decline rate of the relay equipment with a preset attenuation threshold to determine whether maintenance is required for the equipment. Combine the equipment importance weight parameter, calculate the maintenance task priority of the equipment, sort the maintenance tasks, and obtain a list of maintenance task priorities;

[0069] S4: Based on the list of maintenance task priorities, obtain the load current, opening and closing times, and current-carrying time of the relay equipment, calculate the mean and standard deviation of the load change rate, judge the load fluctuation situation, and adjust the maintenance cycle according to the set load fluctuation threshold to obtain the maintenance adjustment amount of the relay equipment;

[0070] S5: Based on the maintenance adjustment amount of the relay equipment and the list of maintenance task priorities, calculate the required number of maintenance personnel and the required amount of spare parts reserves for the relay protection relay, and adjust the maintenance time window to obtain the relay equipment maintenance resource allocation information.

[0071] The change rate of the operating state of the relay equipment includes the coil current change rate, contact resistance increment rate, tripping current threshold fluctuation trend, and protection logic trigger frequency change value. The health decline rate of the relay equipment is specifically the health score attenuation rate, coil aging trend value, contact wear growth amount, and abnormal relay operation ratio. The list of maintenance task priorities includes maintenance task sorting coefficients, fault impact level coefficients, health decline evaluation values, and task execution urgency. The maintenance adjustment amount of the relay equipment is specifically the maintenance interval correction value, load fluctuation impact coefficient, maintenance plan adjustment time, and equipment maintenance level change information. The relay equipment maintenance resource allocation information includes the required number of maintenance personnel, the required amount of spare parts reserves, the maintenance time window, and the task execution work order number.

[0072] Please refer to Figure 2 , and the specific steps for obtaining the change rate of the operating state of the relay equipment are as follows:

[0073] S111: Based on the operating parameters of the relay equipment, obtain the coil current, contact resistance, tripping current threshold, and relay protection logic trigger times, and set short-term, medium-term, and long-term time windows. Calculate the data change rate of each operating parameter within each time window, using the formula:

[0074] ;

[0075] Calculate the change rate of the operating parameters within each time window to obtain the operating parameter change information;

[0076] Among them, represents the change rate of the th operating parameter within the time , represents the th operating parameter at the moment of time , represents the th operating parameter at the time of , represents the time length of the time window ;

[0077] Based on the operating parameters of the relay equipment, coil current, contact resistance, trip current threshold, and the number of times of relay protection logic triggering are obtained. To ensure the time continuity of the data, short-term (e.g., 5 minutes), medium-term (e.g., 30 minutes), and long-term (e.g., 2 hours) time windows are set, and the operating parameter values within the corresponding time ranges are stored respectively for subsequent calculations. The operating parameter data of each time window is arranged in a time series. Calculate the difference in parameter values at the current moment and the previous moment using the formula:

[0078] ;

[0079] Among them, represents the value of the operating parameter at the time , represents the value of the parameter at the previous moment, is the time span of the current time window. For example, if corresponds to a 30-minute time window, then minutes. The calculation result is used to measure the change rate of the operating parameter. In an actual example, if the coil current of the relay equipment was 5A 10 minutes ago and the current value has increased to 5.5A, then the change rate of the coil current is:

[0080] ;

[0081] Similarly, calculate the change rates of contact resistance, trip current threshold, and the number of times of relay protection logic triggering. The results of the change rates of all parameters are stored in the data set to form the operating parameter change information.

[0082] S112: Invoke the operating parameter change information, calculate the change trends of each parameter within different time windows, and use linear regression to fit the slope of the trend change to obtain the slope of the operating state change;

[0083] Call the running parameter change information, calculate the change trends of each parameter within short-term, medium-term, and long-term time windows, establish a trend model using time series data, obtain the trend values of each parameter over time, and use linear regression to fit the data and calculate the slope , where the slope calculation method is:

[0084] ;

[0085] Among them, represents the change trend slope of the th parameter within the current time window, is the number of sampling points within the time window, represents the mean of the time series, represents the average change rate of the th parameter. For example, if the contact resistance is continuously sampled 6 times within a 30-minute time window, obtaining 0.02Ω, 0.021Ω, 0.022Ω, 0.023Ω, 0.025Ω, 0.026Ω respectively, then calculate the average value:

[0086] ;

[0087] Then calculate the mean of the time series:

[0088] ;

[0089] Substitute into the formula to calculate the slope , and calculate the change trend slope of the contact resistance:

[0090] ;

[0091] Obtain the slope value , and obtain the change slope of the operating state.

[0092] S113: Call the change slope of the operating state, and based on the mean and variance of the change rate of each parameter, screen the operating parameters whose change trends exceed the preset change threshold, and calculate the proportion of the change rate of the parameters to obtain the change rate of the relay equipment operating state.

[0093] Call the change slope of the operating state, calculate the change range based on the mean and variance of the change rate of each parameter, screen the parameters whose change trends exceed the preset change threshold, set the preset threshold range, and the threshold setting method is as follows:

[0094] Adopt statistical methods, based on the historical data of normally operating equipment, calculate the mean of the change rate and the standard deviation ;

[0095] Set a 95% confidence interval, that is:

[0096] ;

[0097] Among them, is the preset change threshold for the th parameter;

[0098] For example, if the average value of the contact resistance change rate of the relay equipment is 0.022 Ω and the standard deviation is 0.002 Ω, then calculate the threshold:

[0099] ;

[0100] When the contact resistance change rate exceeds 0.026 Ω, it is determined as an abnormal change and enters the screening list. Screen all operating parameters that exceed the preset change threshold, and calculate the proportion of their change rates. Adopt the normalization calculation method:

[0101] ;

[0102] Among them, represents the proportion of the change rate of the th parameter. Substitute the parameters from the previous step and calculate the proportion of the change rate:

[0103] ;

[0104] This result shows that the proportion of the change rate of the contact resistance is 23.4%. Compared with other parameters, the change amplitude is smaller. Screen the parameters whose change trend exceeds the threshold to obtain the change rate of the operating state of the relay equipment.

[0105] Please refer to Figure 3 , the specific steps for obtaining the decline rate of the health of the relay equipment are as follows:

[0106] S211: Based on the change rate of the operating state of the relay equipment, use the formula:

[0107] ;

[0108] Calculate the health score to obtain the health information of the relay equipment;

[0109] Among them, represents the health score, represents the current change rate of the th operating parameter, represents the influence weight of the th operating parameter, represents the total number of operating parameters;

[0110] Based on the change rate of the operating state of the relay equipment, calculate the health score. First, call the current change rate of each operating parameter , and introduce the corresponding influence weights , the setting of the influence weights is based on the criticality of equipment operation, the influence intensity on the relay protection system, and the historical statistical data of equipment failures. Among them, the weights of key equipment (such as high-load relays) are relatively high, and the weights of non-key equipment are relatively low. For example, the weight of a high-load relay can be set to 0.4, while the weight of an ordinary relay is set to 0.2. The formula is used:

[0111] ;

[0112] Calculate the health score, and set the total number of operating parameters , and calculate the weighted change rate of each parameter respectively. For example, if the coil current change rate of the equipment , the contact resistance change rate , the trip current threshold change rate , the number of times the relay protection logic is triggered change rate , and the corresponding weights are 0.3, 0.3, 0.2, 0.2 respectively, then calculate:

[0113]

[0114] ;

[0115] Calculate the health score as , indicating that the relay equipment is relatively healthy, and obtain the health information of the relay equipment.

[0116] S212: Invoke the health information of the relay equipment, set the health threshold, screen the equipment with a health score lower than the health threshold, and obtain the information on the coil aging degree, contact wear degree, and relay operation times of the equipment to obtain the set of equipment with a health lower than the threshold;

[0117] Invoke the health information of the relay equipment, set the health threshold, and screen the equipment with a health score lower than the health threshold. The setting of the health threshold is based on historical operation data, and the threshold is calculated using the mean and standard deviation based on the normal operation state of the equipment. The setting method is as follows:

[0118] Statistical mean health of all normally operating equipment and standard deviation ;

[0119] Set the health threshold ;

[0120] If the equipment health score is lower than , then it enters the low-health screening set.

[0121] For example, the historical health mean of the equipment , standard deviation ;

[0122] Calculate the health threshold:

[0123] ;

[0124] If the health score calculated by a certain device (lower than 0.95), then the device enters the low-health screening set, and the coil aging degree, contact wear degree, and relay action times of the device are extracted through the operation log and device maintenance data, and stored in the device set with health lower than the threshold.

[0125] S213: Call the device set with health lower than the threshold, calculate the decay rate of the health score per unit time, and obtain the health decline rate of the relay device.

[0126] Call the device set with health lower than the threshold, calculate the decay rate of the health score per unit time, use the linear regression method to fit the health change trend, and calculate the health decline rate , and the calculation method is ; Among them, is the health score at the current moment, is the health score at the previous moment, is the time interval. It is set that the device calculates the health every 24 hours. If the health score of a certain device was 0.96 yesterday and the current health score is 0.94, then calculate:

[0127] ;

[0128] It shows that the health decline rate is 0.00083. If the absolute value of this value exceeds the preset health decline warning threshold (for example, -0.001, and the threshold is set by adding twice the standard deviation of the health decline rate to the average decline rate), then the maintenance plan of this device needs to be concerned, and the health decline rate of the relay device is obtained.

[0129] Please refer to Figure 4 , and the specific steps for obtaining the maintenance task priority list are as follows:

[0130] S311: Based on the health decline rate of the relay device, compare it with the preset decay threshold, judge whether the device needs to be maintained, screen the devices with a health decline rate higher than the decay threshold, and obtain the device set to be maintained;

[0131] Based on the health decline rate of the relay device, compare it with the preset decay threshold, judge whether the device needs to be maintained, and obtain the health decline rate of each device , and the calculation method of this rate adopts the time change rate of the foregoing health score, and the decay threshold is set As the maintenance determination criterion, the threshold is set based on the range of health degree changes of normally operating devices, and the setting method is as follows: Statistically calculate the average value of the health degree decline rate of all devices in the normal operating state and the standard deviation ; Set the health degree decay threshold ; If the health degree decline rate of the device is higher than , then it enters the screening set of devices that need maintenance.

[0132] For example: The average value of the health degree decline rate , the standard deviation ;

[0133] Calculate the health degree decay threshold:

[0134] ;

[0135] If the calculated health degree decline rate of a certain device (higher than -0.0002), then this device enters the set of devices that need maintenance.

[0136] S312: Call the set of devices that need maintenance, combine with the device importance weight parameter, and use the formula:

[0137] ;

[0138] Calculate the maintenance task priority of each device;

[0139] Among them, represents the maintenance task priority of the device, represents the health degree decline rate, represents the device importance weight, represents the change amount of the health degree score, represents the time period since the device was last maintained;

[0140] Call the set of devices that need maintenance, combine with the device importance weight parameter, calculate the maintenance task priority of the device, and the device importance weight parameter is set according to the criticality of the device in the relay protection system. Higher weights are set for key devices (such as main relays), and lower weights are set for ordinary devices. The setting method is as follows: The devices are classified according to the operation risk level, and the importance level is divided, such as high priority , medium priority , low priority ; Calculate the change amount of the device health degree score ; Calculate the time period since the device was last maintained , in hours; Use the formula:

[0141] ;

[0142] Calculate the priority of equipment maintenance tasks.

[0143] For example: Set the rate of decline in equipment health , the importance weight of the equipment , the change amount of the health score , the time interval since the last maintenance hours; Calculate the priority of equipment maintenance tasks:

[0144] ;

[0145] Obtain the priority of equipment maintenance tasks.

[0146] S313: Invoke the priority of the equipment maintenance task, sort the equipment to be maintained according to the priority, and obtain the maintenance task priority list.

[0147] Invoke the priority of the equipment maintenance task, sort the equipment to be maintained according to the priority, and sort the priorities of all equipment in descending order. The larger the priority value, the higher the urgency of equipment maintenance. Generate a maintenance task priority list according to the sorting order. For example: Equipment number A1, maintenance task priority 0.000550, ranking 1; Equipment number B3, maintenance task priority 0.000520, ranking 2; Equipment number C5, maintenance task priority 0.000405, ranking 3; Finally, obtain the maintenance task priority list.

[0148] Please refer to Figure 5 , the specific steps for obtaining the adjustment amount of relay equipment maintenance are as follows:

[0149] S411: Based on the maintenance task priority list, obtain the load current, number of opening and closing operations, and current-carrying time of the relay equipment, and calculate the mean and standard deviation of the load change rate to obtain the load change rate statistical value;

[0150] Based on the maintenance task priority list, obtain the load current, number of opening and closing operations, and current-carrying time of the relay equipment, calculate the mean and standard deviation of the load change rate, extract the load current from the historical operation data of the equipment , the number of opening and closing operations and the current-carrying time , calculate the load change rate of each equipment in different time periods. The calculation method is as follows:

[0151] ;

[0152] Among them, represents the load change rate of a certain equipment at time , and respectively represent the load currents of the current and previous time periods. Calculate the mean value for all time points Calculate the mean and the standard deviation :

[0153] ;

[0154] ;

[0155] For example: Equipment load current data: , , ;

[0156] Calculate the load change rate:

[0157] ;

[0158] ;

[0159] Calculate the mean value of the load change rate:

[0160] ;

[0161] Calculate the standard deviation:

[0162] ;

[0163] Obtain the statistical value of the load change rate.

[0164] S412: Invoke the statistical value of the load change rate, judge the load fluctuation situation, and compare it with the preset load fluctuation threshold to determine whether it is necessary to adjust the maintenance cycle. Use the formula:

[0165] ;

[0166] Calculate the adjusted maintenance cycle;

[0167] Among them, represents the adjusted maintenance cycle, represents the current maintenance cycle, represents the standard deviation of the load change rate, represents the mean value of the load change rate;

[0168] Invoke the statistical value of the load change rate, judge the load fluctuation situation, and compare it with the preset load fluctuation threshold for comparison to determine whether it is necessary to adjust the maintenance cycle. The load fluctuation threshold is set as follows: Calculate the mean value and the standard deviation of the load change rate of historical data; Set the load fluctuation threshold ; If the currently calculated standard deviation Higher than , the maintenance cycle needs to be adjusted.

[0169] For example: the average historical load change rate , standard deviation ;

[0170] Calculate the load fluctuation threshold:

[0171] ;

[0172] Current standard deviation (greater than 0.08), the maintenance cycle needs to be adjusted.

[0173] Adopt the formula:

[0174] ;

[0175] Set the current maintenance cycle days, substitute into:

[0176] ;

[0177] Calculate the adjusted maintenance cycle .

[0178] S413: Call the adjusted maintenance cycle, calculate the required adjustment amount according to the current maintenance cycle, and obtain the relay equipment maintenance adjustment amount.

[0179] Call the adjusted maintenance cycle and calculate the required adjustment amount. The calculation method is as follows:

[0180] ;

[0181] For example: the maintenance cycle before adjustment days, the maintenance cycle after adjustment days; Calculate the adjustment amount:

[0182] ;

[0183] Obtain the relay equipment maintenance adjustment amount , the maintenance cycle is adjusted from 180 days to 201.6 days, and the relay equipment maintenance adjustment amount is obtained.

[0184] Please refer to Figure 6 , the specific steps for obtaining the relay equipment maintenance resource allocation information are as follows:

[0185] S511: Based on the relay equipment maintenance adjustment amount and the maintenance task priority list, calculate the demand for maintenance personnel for relay protection relays, obtain the number of maintenance tasks, the standard working hours per task, and the available working hour resources, and obtain the maintenance personnel demand information;

[0186] Based on the maintenance adjustment amount and the priority list of maintenance tasks for relay equipment, determine the number of maintenance tasks to be completed. For example, it is planned to perform regular maintenance on relay equipment units. Consult the standard man-hours for each task. Assume that the standard man-hours for each task is hours. Statistically analyze the available man-hour resources. Suppose there are currently maintenance personnel, and each person can work hours per day. Then the total available man-hour resources are hours. Multiply the number of maintenance tasks by the standard man-hours per task to obtain the total man-hour requirement, that is, hours. Compare the total man-hour requirement with the available man-hour resources. If the total man-hour requirement is greater than the available man-hour resources, additional maintenance personnel are needed; otherwise, the existing personnel are sufficient to complete the tasks.

[0187] S512: Invoke the information on the demand for maintenance personnel, combine it with the spare part consumption situation of equipment maintenance tasks, and combine the current inventory status and the safety stock threshold. Use the formula:

[0188] ;

[0189] Calculate the spare part reserve demand;

[0190] Among them, represents the spare part reserve demand, represents the spare part consumption rate of the rd type of equipment, represents the adjusted maintenance cycle of the th type of equipment, represents the supply rate of replenishable spare parts per unit time for the th type of equipment, represents the current inventory, represents the total number of equipment;

[0191] Invoke the information on the demand for maintenance personnel, combine it with the spare part consumption situation of equipment maintenance tasks, and statistically analyze the spare part consumption rate of each type of equipment , for example, for the th type of equipment, on average, spare parts are consumed each time for maintenance. Determine the adjusted maintenance cycle of this equipment. Suppose the adjusted maintenance cycle is days. Find out the supply rate of replenishable spare parts per unit time for this equipment. Suppose the supplier can provide spare parts per week. Then pieces / day. Calculate the number of spare parts required within a maintenance cycle, that is:

[0192] ;

[0193] Meanwhile, count the current inventory , assuming there are spare parts in the current inventory, and use the formula:

[0194] ;

[0195] Calculate the spare parts reserve demand, indicating that additional spare parts need to be reserved.

[0196] S513: Invoke the spare parts reserve demand, combine it with the demand for maintenance personnel, adjust the maintenance time window, optimize the task allocation, and obtain the relay equipment maintenance resource allocation information.

[0197] Invoke the spare parts reserve demand, combine it with the demand for maintenance personnel, evaluate the arrangement of the current maintenance time window. Assume the current maintenance time window is from to from Monday to Friday every week. Consider adjusting the maintenance time window, for example, extending the daily working hours or adding weekend work to meet the needs of maintenance personnel, optimize the task allocation, assign high-priority maintenance tasks to experienced maintenance personnel, and low-priority tasks to other personnel to ensure the reasonable allocation of tasks according to priorities. Combine the supply situation of spare parts, reasonably arrange the procurement and inventory of spare parts to ensure sufficient supply of spare parts within the adjusted maintenance time window and avoid maintenance delays caused by spare parts shortages. After the above adjustments, obtain the optimized allocation information of relay equipment maintenance resources.

[0198] A relay protection equipment predictive maintenance system, which is used to execute the above relay protection equipment predictive maintenance method. The system includes:

[0199] The operating status analysis module calculates the change trend of each operating parameter within each time window based on the relay equipment operating parameters, and obtains the relay equipment operating status change rate;

[0200] The health degree change analysis module calculates the health degree score of the relay equipment based on the relay equipment operating status change rate, screens out the equipment with a health degree score lower than the health degree threshold, calculates the decay rate of the health score per unit time, and obtains the relay equipment health degree decline rate;

[0201] The maintenance task ranking module determines whether maintenance is required for the equipment based on the relay equipment health degree decline rate, combines the equipment importance weight parameter, calculates the priority of the equipment maintenance task, and obtains the maintenance task priority list;

[0202] Based on the maintenance task priority list, the maintenance cycle adjustment module obtains the load current, opening and closing times, and current-carrying time of relay equipment, calculates the mean and standard deviation of the load change rate, judges the load fluctuation situation, adjusts the maintenance cycle, and obtains the maintenance adjustment amount of relay equipment;

[0203] Based on the maintenance adjustment amount of relay equipment and the maintenance task priority list, the maintenance resource scheduling module calculates the demand for maintenance personnel and the demand for spare part reserves of relay protection relays, and adjusts the maintenance time window to obtain the relay equipment maintenance resource allocation information.

[0204] The above are only the preferred embodiments of the present invention, and do not limit the present invention in other forms. Any person skilled in the art may use the technical content disclosed above to make changes or modifications 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 content of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A method for predictive maintenance of a relay protection device, characterized in that, It includes the following steps: S1: Based on the operating parameters of relay equipment, calculate the change trend of each operating parameter within each time window to obtain the change rate of the operating state of relay equipment; S2: Based on the change rate of the operating state of the relay equipment, calculate the health score of the relay equipment, screen the equipment with a health score lower than the health threshold, calculate the decay rate of the health score per unit time to obtain the decline rate of the health of the relay equipment; S3: Based on the decline rate of the health of the relay equipment, determine whether maintenance of the equipment is required, combine the importance weight parameters of the equipment, calculate the priority of the equipment maintenance task to obtain a list of maintenance task priorities; S4: Based on the list of maintenance task priorities, obtain the load current, opening times, and current-carrying time of the relay equipment, calculate the mean and standard deviation of the load change rate, judge the load fluctuation situation, adjust the maintenance period to obtain the maintenance adjustment amount of the relay equipment; S5: Based on the maintenance adjustment amount of the relay equipment and the list of maintenance task priorities, calculate the required number of maintenance personnel and the required spare parts reserve for the relay protection relay, and adjust the maintenance time window to obtain the relay equipment maintenance resource allocation information; The specific steps for obtaining the relay equipment maintenance resource allocation information are as follows: S511: Based on the maintenance adjustment amount of the relay equipment and the list of maintenance task priorities, calculate the required number of maintenance personnel for the relay protection relay, obtain the number of maintenance tasks, the standard working hours per task, and the available working hour resources to obtain the information on the required number of maintenance personnel; S512: Call the information on the required number of maintenance personnel, combine the spare parts consumption situation of the equipment maintenance task, and combine the current inventory status and the safety reserve threshold, and use the formula: ； Calculate the required spare parts reserve; in, represents the spare parts reserve demand, Representative Spare parts consumption rate of this type of equipment, Representative The maintenance cycle after the equipment is adjusted, Representative The supply rate of spare parts per unit time for this type of equipment, Represents the current inventory level, Represents the total number of devices; S513: Call the required spare parts reserve, combine the required number of maintenance personnel, evaluate the arrangement of the current maintenance time window, adjust the maintenance time window, optimize the task allocation, assign high-priority maintenance tasks to experienced maintenance personnel, assign low-priority tasks to other personnel, and arrange the procurement and inventory of spare parts in combination with the supply situation of spare parts to obtain the relay equipment maintenance resource allocation information.

2. The predictive maintenance method for relay protection equipment according to claim 1, wherein The change rate of the operating state of the relay equipment includes the coil current change rate, the contact resistance increment rate, the tripping current threshold fluctuation trend, and the change value of the protection logic trigger frequency. The decline rate of the health of the relay equipment is specifically the health score decay rate, the coil aging trend value, the contact wear growth amount, and the abnormal ratio of relay operation. The list of maintenance task priorities includes the maintenance task sorting coefficient, the fault impact level coefficient, the health decline evaluation value, and the task execution urgency. The maintenance adjustment amount of the relay equipment is specifically the maintenance interval correction value, the load fluctuation influence coefficient, the maintenance plan adjustment time, and the equipment maintenance level change information. The relay equipment maintenance resource allocation information includes the required number of maintenance personnel, the required spare parts reserve, the maintenance time window, and the task execution work order number.

3. The predictive maintenance method for relay protection equipment according to claim 1, characterized in that The specific steps for obtaining the change rate of the operating state of the relay equipment are as follows: S111: Based on the operating parameters of the relay equipment, the coil current, contact resistance, trip current threshold, and the number of relay protection logic triggers are obtained. Short-term, medium-term, and long-term time windows are set, and the data change rate of each operating parameter in each time window is calculated using the formula: ； Calculate the rate of change of operating parameters in each time window to obtain operating parameter change information; in, Representative Operating parameters at time The rate of change within Representative time The moment operating parameters, Representative time No. operating parameters, Represents a time window the length of time; S112: Calling the operating parameter change information, calculating the change trend of each parameter in different time windows, and fitting the slope of the trend change using linear regression to obtain the operating state change slope; S113: Call the operating state change slope, and based on the mean and variance of the change rate of each parameter, screen the operating parameters whose change trend exceeds the preset change threshold, and calculate the change rate ratio of the parameters to obtain the operating state change rate of the relay device.

4. The predictive maintenance method for relay protection equipment according to claim 1, wherein The steps for obtaining the health degradation rate of the relay device are specifically as follows: S211: Based on the rate of change of the operating state of the relay device, the formula is used: ； Calculate the health score and obtain the health information of the relay equipment; in, represents the health score, Representative The current rate of change of the operating parameters, Representative The influence weight of various operating parameters, Represents the total number of operating parameters; S212: Retrieving the relay device health information, setting a health threshold, screening devices with health scores below the health threshold, obtaining information on the device's coil aging, contact wear, and relay operation times, and obtaining a set of devices with health scores below the threshold; S213: Call the device set whose health is lower than the threshold, calculate the decay rate of the health score per unit time, and obtain the health degradation rate of the relay device.

5. The predictive maintenance method for a relay protection device according to claim 1, wherein The steps for obtaining the maintenance task priority list are specifically as follows: S311: Based on the health degradation rate of the relay device, the health degradation rate is compared with a preset attenuation threshold to determine whether the device needs maintenance, and the devices with a health degradation rate higher than the attenuation threshold are screened to obtain a set of devices requiring maintenance; S312: Call the set of equipment requiring maintenance, and use the following formula in combination with the equipment importance weight parameter: ； Calculate the maintenance task priority for each device; Among them, represents the priority of the equipment maintenance task, represents the rate of decline in health, represents the importance weight of the equipment, represents the change in the health score, represents the time period since the equipment was last maintained; S313: Calling the maintenance task priority of the equipment, sorting the equipment to be maintained according to the priority, and obtaining a maintenance task priority list.

6. The predictive maintenance method for relay protection equipment according to claim 1, characterized in that, The steps for obtaining the maintenance adjustment amount of the relay equipment are specifically as follows: S411: Based on the maintenance task priority list, obtain the load current, breaking times, and flow time of the relay device, and calculate the mean and standard deviation of the load change rate to obtain a load change rate statistical value; S412: Call the load change rate statistics to determine the load fluctuation situation, and compare it with the preset load fluctuation threshold to determine whether the maintenance cycle needs to be adjusted. The formula is: ； Calculate the adjusted maintenance interval; Among them, represents the adjusted maintenance cycle, represents the current maintenance cycle, represents the standard deviation of the load change rate, represents the mean value of the load change rate; S413: Calling the adjusted maintenance cycle, calculating the required adjustment amount according to the current maintenance cycle, and obtaining the maintenance adjustment amount of the relay equipment.

7. A predictive maintenance system for relay protection equipment, characterized in that: The predictive maintenance method for relay protection equipment according to any one of claims 1 to 6, wherein the system comprises: The operating status analysis module calculates the change trend of each operating parameter in each time window based on the operating parameters of the relay equipment and obtains the rate of change of the operating status of the relay equipment; The health status change analysis module filters out the equipment with a health score lower than the health threshold based on the change rate of the operating status of the relay equipment, calculates the decay rate of the health score per unit time, and obtains the decline rate of the health status of the relay equipment; The maintenance task ranking module determines whether maintenance is required for the equipment based on the decline rate of the health status of the relay equipment, calculates the priority of the equipment maintenance task, and obtains the maintenance task priority list; The maintenance cycle adjustment module calculates the mean and standard deviation of the load change rate based on the maintenance task priority list, determines the load fluctuation situation, adjusts the maintenance cycle, and obtains the maintenance adjustment amount of the relay equipment; The maintenance resource scheduling module calculates the demand for maintenance personnel and the demand for spare part reserves of the relay protection relay based on the maintenance adjustment amount of the relay equipment and the maintenance task priority list, and adjusts the maintenance time window to obtain the relay equipment maintenance resource allocation information.

Images