Extra-high voltage filter field phase selection closing circuit breaker health assessment method and system

Abstract

The invention discloses an extra-high voltage filter field phase selection closing circuit breaker health assessment method and system, and the method comprises the steps: setting the data of a circuit breaker in a normal state as a reference value based on the field operation performance data of the circuit breaker, carrying out the normalization processing according to the data distribution characteristics, collecting the performance parameters into a recorder, and recording the performance parameters of the circuit breaker; dividing state grade intervals according to normal working and abnormal data of the circuit breaker, setting membership degrees of various parameter monitoring quantities corresponding to different state intervals in the cloud model, taking the membership degrees confirmed by the cloud model as health degree judgment basis of various performance indexes of the filter field phase selection closing circuit breaker, and performing screening to obtain a health degree judgment result; the circuit breaker health influence factors are weighted in a subjective and objective combination mode, the arithmetic mean value of the two factors is calculated to serve as a constant weight, then the comprehensive weight of each evaluation index is obtained through variable weight processing, and the running state of the current circuit breaker is judged through a fuzzy operator. Differentiated health state monitoring can be carried out on different extra-high voltage filter field phase selection closing circuit breakers.

Description

Technical Field

[0001] The present invention relates to the field of equipment operation and maintenance decision-making, and particularly to a method and system for health assessment of a phase-selection closing breaker in a UHV filter yard. Background Art

[0002] The phase-selection closing breaker in the filter yard is a key device in the converter station of the power system for switching the reactive power compensation device. Its safe and stable operation is one of the tasks to ensure the safety of the power transmission system. Conducting accurate health status assessment on such breakers and implementing differential operation and maintenance management are key links to ensure stable power transmission and avoid major power accidents. Although the current converter station has carried out monitoring work on multiple performance parameters of the breaker, the monitoring system still has many shortcomings. On the one hand, the lack of key monitoring indicators makes it difficult to comprehensively cover the actual operation status of the breaker; on the other hand, qualitative indicators cannot be incorporated into the assessment system, resulting in limited assessment dimensions and the unique characteristics of different breakers not being fully considered. In addition, there is a certain degree of overlap in the assessment results, making it difficult to accurately distinguish the health levels of different breakers, and there is a lack of personalized monitoring means for different breakers, which cannot meet the refined requirements of actual operation and maintenance.

[0003] With the rapid development of digital converter stations, higher requirements are put forward for the accuracy, reliability and real-time performance of the breaker health assessment results. Traditional maintenance modes, such as fault maintenance and regular maintenance, have obvious limitations. Fault maintenance is often carried out after the equipment fails, which may lead to power supply interruption and affect the user experience; while regular maintenance is prone to over-maintenance, which not only wastes manpower, material resources and financial resources, but also may cause unnecessary damage to the equipment.

[0004] In recent years, there has been an obvious development trend in the field of breaker maintenance, which is gradually shifting from traditional fault maintenance and regular maintenance modes to condition-based maintenance and reliability-centered maintenance modes. Condition-based maintenance emphasizes determining whether to carry out maintenance according to the actual operation status of the equipment, and requires real-time acquisition of key characteristic parameters during the operation of the equipment. Specifically, it is necessary to carefully compare the parameter monitoring values collected by various sensor devices and data acquisition devices connected to the breaker with the test values obtained from the specified values of the equipment, factory tests and formal tests. In this way, the operation status of the breaker can be timely and accurately grasped, providing a scientific basis for subsequent maintenance decisions.

[0005] Applying condition-based maintenance technology to the equipment health status assessment of filter field phase-selection closing circuit breakers has significant advantages. It can effectively make up for the deficiencies of existing assessment methods and improve the accuracy and reliability of assessment results. Based on accurate assessment results, personalized operation and maintenance strategies can be formulated for circuit breakers in different health states, realizing the optimal allocation of resources, improving operation and maintenance efficiency, and reducing operation and maintenance costs. This not only helps to ensure the safe and stable operation of the power system, but also provides strong support for the sustainable development of power enterprises.

[0006] Most of the data monitored by current circuit breaker health assessment methods are processed for specific data selected for special monitoring, which is difficult to reflect the overall health condition of the circuit breaker. At the same time, filter field phase-selection closing circuit breakers have problems such as frequent switching and frequent failures, and there is currently no suitable health assessment method for filter field phase-selection closing circuit breakers in UHV converter stations. Summary of the Invention

[0007] Embodiments of the present invention provide a health assessment method and system for UHV filter field phase-selection closing circuit breakers. Based on various data characterizing the filter field phase-selection closing circuit breaker, normalization processing is performed according to the data characteristics. Then, the membership degrees of different states of each data are monitored using the set data, the cloud model is used to confirm the health degree of the closing circuit breaker, and then the comprehensive weight is obtained through the subjective analytic hierarchy process and the objective weighting method. Finally, the health state of the current closing circuit breaker is obtained through the fuzzy algorithm result.

[0008] To solve the problem of equipment health status assessment of UHV filter field phase-selection closing circuit breakers.

[0009] In the first aspect, a health assessment method and system for UHV filter field phase-selection closing circuit breakers are provided, including:

[0010] Based on the on-site operation performance data of the circuit breaker, including the on-site operation data of parameters such as the mechanical performance, switching performance, and insulation performance of the circuit breaker in the normal state and the fault state, the data of the circuit breaker in the normal state is set as the reference value, and normalization processing is performed according to the data distribution characteristics of each monitoring index of the filter field phase-selection closing circuit breaker;

[0011] The mechanical performance parameters of the circuit breaker include closing time, closing auxiliary switch action time, closing action dispersion, etc.; the switching performance parameters include pre-breakdown voltage, pre-breakdown time, pre-breakdown field strength, arc energy, closing current, breaking current and voltage, etc. of the circuit breaker during closing; and parameters such as micro water content and partial discharge amount characterizing the insulation performance.

[0012] The normalization formula for the closing time characterizing the mechanical performance is:

[0013]

[0014] Where \(Y1\) is the normalized value, \(tc1\) is the closing time recorded for each operation, \(m\) is the reference value in the normal state, which is taken as the average value of the normal monitoring data here; \(n\) is the degree of data dispersion in the normal state, and the value of \(n\) is twice the variance;

[0015] Divide the state level intervals by the abnormal data in the factory test and fault state of the circuit breaker, and use the cloud model to determine the membership degrees of each parameter monitoring quantity corresponding to different state intervals;

[0016] Based on the above processing results, it is proposed to use the membership degree confirmed by the cloud model as the health degree of each performance index of the filter field selected phase closing circuit breaker;

[0017] Assign weights to the health impact factors of the circuit breaker by combining subjective and objective methods. The subjective weighting method uses the subjective analytic hierarchy process, and the objective weighting method uses the entropy weight method. Then calculate the arithmetic mean of the two as the constant weight, and finally through variable weight processing, obtain the comprehensive weights of each evaluation index;

[0018] The weight variable weight formula is:

[0019]

[0020] Where \(w_i'\) is the weight of the \(i\)-th index after variable weight adjustment; \(w_i\) is the initial weight of the \(i\)-th index, which is used to measure the importance in the calculation; \(\alpha\) is the variable weight coefficient, and \(\alpha\) takes the average value; \(n\) represents the total number of indexes;

[0021] Judge the operating state of the current circuit breaker through the fuzzy operator, and use the calculated evaluation result as the health state of the circuit breaker in the current state. The formula for calculating the state matrix \(B\) with the fuzzy relation matrix \(R\) and the weight set \(W\) is:

[0022]

[0023] Where \(W\) is the weight set, \(R\) is the fuzzy relation matrix, and \(B\) is the operating state of the current circuit breaker.

[0024] Where \(W\) is the weight set, \(R\) is the fuzzy relation matrix, and \(B\) is the operating state of the current circuit breaker.

[0025] In the second aspect, a computer-readable storage medium is provided, on which computer program instructions are stored; when the computer program instructions are executed by a processor, the method for evaluating the health state of the UHV filter field selected phase closing circuit breaker as described in the embodiments of the first aspect is implemented.

[0026] In the third aspect, a calculation system for evaluating the health state of the UHV filter field selected phase closing circuit breaker is provided, including: the computer-readable storage medium as described in the embodiments of the second aspect.

[0027] Preferably, the normal performance parameters in the data are set as calibration points, the information punctuation marks obtained through collection and processing are used as target points, and the membership degrees of different state intervals corresponding to each parameter monitoring quantity are determined according to the different distances between the target points and the calibration points.

[0028] Preferably, the health degree is screened by setting the number of deviations of each parameter, and different deviation values can be set differently in different breaker working environments.

[0029] Preferably, in the subjective analytic hierarchy process, when an operator finds that the health degree of each performance index of a certain breaker in the cloud model is relatively low, the operator retrieves the data of the target breaker, checks whether the data is abnormal, conducts a comparison of abnormal data, and queries the data change trend, etc., to judge the health status of the breaker.

[0030] The advantages of a method and system for evaluating the health status of a UHV filter field selected-phase closing breaker provided by the present invention are as follows:

[0031] 1. The present invention can normalize each performance parameter according to its distribution characteristics, use the cloud model to determine the membership degrees of each performance parameter corresponding to different state levels, determine the constant weight by the method of combining subjective and objective factors, obtain the final variable weight by the variable weight formula, and finally obtain the result of the state evaluation of the filter field selected-phase closing breaker through the fuzzy operator. Each item of data can be modified according to actual operation needs, providing technical support for the differential operation and maintenance of the breaker;

[0032] 2. The present invention processes the collected data multiple times and introduces manual evaluation, which maximally avoids the interference of accidental abnormal data on the final evaluation result and ensures the correctness and reliability of the evaluation result. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 is a flowchart of a method and system for evaluating the health of a UHV filter field selected-phase closing breaker according to an embodiment of the present invention;

[0035] Figure 2 is a structural diagram of a method and system for evaluating the health of a UHV filter field selected-phase closing breaker according to the present invention;

[0036] Among them:

[0037] 101. Current sensor; 102. Voltage signal acquisition; 103. Oscillograph data recorder; 104. Auxiliary switch; 105. Phase selection closing controller; 106. Circuit breaker health assessment system. Specific implementation mode

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] The embodiments of the present invention disclose a method and system for health assessment of a phase selection closing circuit breaker in a UHV filter yard. As Figure 1 shown, the method of the embodiments of the present invention specifically includes the following steps:

[0040] Step S101: Based on the on-site operation data characterizing the mechanical performance, switching performance and insulation performance of the phase selection closing circuit breaker in the filter yard, taking the average value of the performance parameters in the normal state as the benchmark, and performing normalization processing according to the data distribution characteristics.

[0041] The mechanical performance parameters of the circuit breaker include closing time, action time of the closing auxiliary switch 104, closing action dispersion, etc.; the switching performance parameters include pre-breakdown voltage, pre-breakdown time, pre-breakdown field strength, arc energy, closing current, breaking current and voltage of the circuit breaker; and parameters such as micro water content and partial discharge amount characterizing the insulation performance. The circuit breaker in the embodiments of the present invention can be an 800 kV phase selection closing circuit breaker in the filter yard.

[0042] Taking the closing time parameter characterizing the mechanical performance as an example, the closing time range of phase A of the circuit breaker group in the filter yard under normal on-site conditions is the normal state range V1. Taking the average value tc1 of its detected values as the reference value and taking the standard deviation of its normal range as the normal state boundary line, during normalization, perform normalization processing according to the characteristic that the closing time follows a normal distribution and process it according to the Gaussian function, so as to obtain the normalized value corresponding to the closing time. The remaining parameters are all normalized according to the distribution characteristics of the performance parameters, which will not be elaborated here;

[0043] The normalization formula for the closing time characterizing the mechanical performance is:

[0044]

[0045] Where Y1 is the normalized value, tc1 is the closing time recorded for each action, m is the reference value in the normal state, here taking the average value of the normal monitoring data; n is the degree of dispersion of the data in the normal state, and the n value is twice the variance;

[0046] Step S102: Collect the mechanical performance parameters of the circuit breaker into the recorder, divide the abnormal data in the factory test and fault state of the circuit breaker into state level intervals by the threshold method, and set the membership degrees of each parameter monitor quantity in the cloud model corresponding to different state intervals.

[0047] Divide the fault boundary according to the abnormal data of the circuit breaker in the factory test and fault state. The normalized fault boundary can be obtained from step S101. Thus, the cloud model membership function image can be drawn using the cloud model.

[0048] Taking y1 obtained from the above steps as an example, divide the fault boundaries according to the amount of abnormal data into V1[a, b], V2[c, d], V3[e, f], V4[g, h], etc. Draw the cloud model of the closing time parameter in different states according to the state intervals, and the membership degree in each state can be obtained correspondingly; the calculation of the membership degrees of the remaining health factors is carried out according to S102 and will not be elaborated here. Thus, a fuzzy relation matrix R for constructing the membership degrees of the circuit breaker health factors can be obtained.

[0049] Step S103: Based on the above processing results, propose to use the membership degree confirmed by the cloud model as the health degree of each performance index of the filter field-selective closing circuit breaker.

[0050] Obtain the membership degree value corresponding to the normalized value y1 of the circuit breaker closing time from step S102. According to the maximum membership degree principle, it can be judged which state range this performance parameter is currently in, and thus it can be used as the health degree of each performance index.

[0051] Step S104: Assign weights to the circuit breaker health impact factors through a combination of subjective and objective methods. The subjective weighting method uses the subjective analytic hierarchy process. The subjective analytic hierarchy process means that the staff generates an abnormal data report based on the health degrees of each performance index in the cloud model, and judges the health status of the circuit breaker by comparing the historical data change trend and combining work experience to obtain a subjective score. The objective weighting method uses the entropy weight method, sets the reliability proportion of the data in different environmental equipment to obtain an objective score, and calculates the arithmetic mean of the two as the constant weight. Then, through variable weight processing, the comprehensive weight of each evaluation index is obtained.

[0052] The weight variable weight formula is:

[0053]

[0054] Where is the weight of the i-th index after variable weight adjustment, is the initial weight of the i-th index, α is the variable weight coefficient, and n represents the total number of indexes;

[0055] Taking the operation monitoring data of phase A of the filter field circuit breaker group as an example, by comparing the importance of various monitoring parameters of the filter field circuit breaker, a subjective judgment matrix can be obtained, so that the subjective weight of the health impact factor of the circuit breaker can be obtained; through step S101, the normalized values of each health impact factor can be obtained, and objective entropy weights are assigned according to the entropy values of each index data; then the average value is taken as the constant weight. Considering that different degrees of index deterioration will have different impacts on the overall health state of the circuit breaker, a variable weight formula is used for processing here: , from which the comprehensive weight values of each performance parameter of the circuit breaker can be obtained. Through the above processing, the comprehensive weight set W composed of the health factors of the filter field circuit breaker can be obtained.

[0056] Step S105: Judge the operation state of the current circuit breaker through a fuzzy operator, and use the calculated evaluation result as the health state of the circuit breaker under the current state.

[0057] The membership degree value and comprehensive weight of the filter field circuit breaker are obtained from step S102 and step S104 respectively. The above fuzzy relation matrix and weight set are processed through a fuzzy operator, and the evaluation result obtained therefrom is used as the health state of the currently operating filter field circuit breaker. The formula for calculating the state matrix B with the fuzzy relation matrix R and the weight set W is:

[0058]

[0059] Where W is the weight set, R is the fuzzy relation matrix, and B is the operation state of the current circuit breaker.

[0060] Through the above steps, the health state assessment of the UHV filter field phase-selection closing circuit breaker is realized. The calculation method is simple and reliable, without the need to additionally increase the auxiliary components of the circuit breaker, and the transformation cost is low. Based on this health state assessment method, it is convenient to use the on-site operation data to assess the health state of the circuit breaker.

[0061] In addition, an embodiment of the present invention also provides a computer-readable storage medium, on which computer program instructions are stored; when the computer program instructions are executed by a processor, the health state assessment method of the UHV filter field phase-selection closing circuit breaker as described in the above embodiment is realized.

[0062] In addition, an embodiment of the present invention also provides a health state assessment system for a UHV filter field phase-selection closing circuit breaker, including: the computer-readable storage medium as described in the above embodiment.

[0063] Specifically, as Figure 2As shown in the figure, the system includes: a current sensor 101, a voltage signal acquisition unit 102, a waveform recording data recorder 103, an auxiliary switch 104, a phase selection closing controller 105, and a circuit breaker health assessment system 106. Among them, the current sensor 101 and the voltage signal acquisition unit 102 are used to collect the voltage and current signals of the main line of the filter field. The auxiliary switch 104 changes its signal state driven by the action of the circuit breaker after receiving an instruction from the phase selection closing controller 105. The on / off state of the auxiliary switch 104 represents the change in the opening / closing state of the circuit breaker. The phase selection closing circuit breaker 105 issues opening / closing instructions to the circuit breaker of the filter field. The waveform recording data recorder 103 records the waveforms and data of the voltage and current signals. By jointly processing the data recorded by the phase selection closing controller 105, the real-time state parameters of the circuit breaker of the filter field during each operation can be obtained. The circuit breaker health assessment system 106 can obtain the health state of the current circuit breaker after processing the obtained state data.

[0064] Existing phase selection closing circuit breakers in filter fields generally have a waveform recording data recorder 103 for voltage and current acquisition and a phase selection controller. Therefore, in the embodiments of the present invention, there is no need to additionally increase circuit breaker performance monitoring sensors. The operation state of the circuit breaker can be evaluated by using the data in the waveform recording data recorder 103 for collecting electrical signals and the phase selection closing controller 105 equipped with the phase selection closing circuit breaker. Combining the above-mentioned health state assessment method, a health state assessment system for the phase selection closing circuit breaker in the UHV filter field is formed to complete data processing and analysis and obtain the real-time state assessment result of the circuit breaker.

[0065] In summary, in the embodiments of the present invention, the on-site operation data characterizing the mechanical performance, opening / closing performance, and insulation performance of the phase selection closing circuit breaker in the filter field are normalized according to the parameter distribution characteristics, and the membership degree of the evaluation factors is obtained with abnormal data as the boundary. Then, combined with the comprehensive weight method, the current health state of the circuit breaker is obtained through a fuzzy operator, providing technical support for the differentiated operation and maintenance of the circuit breaker; the evaluation system is stable and reliable, and the state evaluation of the phase selection closing circuit breaker in the filter field is completed based on the existing circuit breaker state monitoring data.

[0066] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method and system for health assessment of a phase-selection closing circuit breaker in a UHV filter yard, characterized in that, It includes the following steps: Step 1: Based on the on-site operation performance data of the circuit breaker, including the on-site operation data of the mechanical performance, switching performance, and insulation performance of the circuit breaker, etc., under normal and fault states, set the data under the normal state of the circuit breaker as the reference value, and normalize the different monitoring data of the filter field-selective closing circuit breaker; The mechanical performance parameters of the circuit breaker include closing time, closing auxiliary switch operation time, and closing action dispersion; the switching performance parameters include pre-breakdown voltage, pre-breakdown time, pre-breakdown field strength, arc energy, closing current, breaking current and voltage during closing of the circuit breaker; and parameters such as micro water content and partial discharge amount characterizing the insulation performance; The normalization formula for the closing time characterizing the mechanical performance is: Y1 is the normalized value, and t c1 is the closing time recorded for each operation, m is the reference value under normal conditions, which is taken as the average value of normal monitoring data here; n is the degree of data dispersion under normal conditions, and the value of n is twice the variance; Step 2: Collect the mechanical performance parameters of the circuit breaker into the recorder, divide the state grade intervals by the threshold method for the abnormal data under the factory test and fault state of the circuit breaker, and set the membership degrees of the corresponding monitored quantities of each parameter in the cloud model for different state intervals; Step 3: Based on the data in the recorder, use the membership degree confirmed by the cloud model as the basis for judging the health degree of each performance index of the filter field-selective closing circuit breaker, and screen by the threshold method; Step 4: Assign weights to the health impact factors of the circuit breaker by combining subjective and objective methods. The subjective weighting method uses the subjective analytic hierarchy process, and the objective weighting method uses the entropy weight method, and calculate the arithmetic mean of the two as the constant weight, and then through variable weight processing, obtain the comprehensive weights of each evaluation index; The weight variable weight formula is: where is the weight of the i-th index after variable weight adjustment; w i is the initial weight of the i-th index, used to measure the importance in the calculation; α is the variable weight coefficient, and α takes the average; n represents the total number of evaluation indicators; Step 5: Judge the current operation state of the circuit breaker through a fuzzy operator, and use the calculated evaluation result as the health state of the circuit breaker under the current state. The formula for calculating the state matrix B with the fuzzy relation matrix R and the weight set W is: The weight variable weight formula is: Where W is the weight set, R is the fuzzy relation matrix, and B is the current operation state of the circuit breaker.

2. The health assessment method and system for the selected-phase closing circuit breaker in the UHV filter yard according to claim 1, wherein: The method for judging the membership degree is to set the normal performance parameters in the data as the calibration points in the cloud model, use the information punctuation points collected and processed as the target points, and determine the membership degrees of the corresponding monitored quantities of each parameter for different state intervals through the relative error between the target point and the calibration point.

3. The healthy evaluation method and system of the UHV filter field phase-selection closing circuit breaker according to claim 2, characterized in that: The health degree is screened by setting the number of deviations of each parameter. Different deviation numbers can be set differently in different working environments of the circuit breaker.

4. The healthy evaluation method and system of the UHV filter field phase-selection closing circuit breaker according to claim 3, characterized in that: The subjective analytic hierarchy process is that the operator generates an abnormal data report based on the health degree of each performance index in the cloud model, and judges the health status of the circuit breaker by comparing the historical data change trend and combining work experience to obtain a subjective score.

5. A method and system for health assessment of a UHV filter substation phase-selection closing circuit breaker, which adopts a method for health state assessment of a UHV filter substation phase-selection closing circuit breaker as described in any one of claims 1-4, characterized in that: It includes a current sensor (101), a voltage signal acquisition unit (102), a waveform recording data recorder (103), an auxiliary switch (104), a phase-selection closing controller (105), and a circuit breaker health assessment system (106). The waveform recording data recorder (103) is connected to the voltage signal acquisition unit (102) through an analog signal. The voltage signal acquisition unit (102) is plugged into the current sensor (101) to collect line voltage and current signals. The phase-selection closing circuit breaker (105) is plugged into the auxiliary switch (104) to record the change of the signal generated by the operation of the circuit breaker after the instruction is issued. The on / off of the auxiliary switch (104) represents the change of the opening / closing state of the circuit breaker. The waveform recording data recorder (103) and the phase-selection closing controller (105) are connected to the circuit breaker health assessment system (106).

6. The method and system for health assessment of the selected-phase closing circuit breaker in the UHV filter yard according to claim 5, wherein: The waveform recording data recorder (103) is connected to the phase-selection closing controller (105) to jointly process the recorded data, and the real-time state parameters of the filter field circuit breaker during each operation can be obtained.

7. The method and system for health assessment of the UHV filter field selected-phase closing circuit breaker according to claim 6, wherein: The waveform recording data recorder (103) preprocesses the input voltage signal, and processes the input signal through a voltage stabilizing circuit and a proportional amplification circuit as the input voltage.

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