Circuit breaker operation state on-line monitoring device and method based on distribution automation

Abstract

The invention relates to a circuit breaker operation state online monitoring device and method based on distribution automation, the device comprises a sensor and conditioning circuit, an A / D conversion and micro-processing module and a processor, the sensor and conditioning circuit comprises a sensor and a signal conditioning circuit connected with the output end of the sensor; the A / D conversion and micro-processing module comprises an analog-to-digital conversion module and a micro-processing module which are connected with the output end of the signal conditioning circuit; the sensors comprise a displacement sensor, an acceleration sensor, a Hall current sensor and a pressure sensor; the system has the advantages of efficient online monitoring, remote online monitoring, accurate and reliable evaluation and high precision.

Description

Technical Field

[0001] The present invention belongs to the technical field of circuit breaker detection, and in particular relates to an online monitoring device and method for circuit breaker operating status based on power distribution automation. Background Art

[0002] As an insulation and arc extinguishing device, the distribution network circuit breaker is the most critical electrical equipment in the switchgear. During normal operation, it is used to switch the operation mode, connect the equipment or line to the circuit or take it out of operation as needed. When the equipment or line fails, it can be quickly cut off to ensure the safe and normal operation of other parts. It plays a dual role of control and protection in the distribution network, and its working state directly affects the safety and reliability of the power system. The reliability of the circuit breaker depends to a large extent on the reliability of its mechanical operating system. The statistical analysis of high-voltage switch accidents shows that among the circuit breaker failures, mechanical failures (including operating mechanisms and control circuits) account for more than 70% of all failures, and other arc extinguishing and insulation failures account for a smaller proportion, and the proportion of heating failures is even lower. On the other hand, the life of circuit breaker contacts is an important aspect of circuit breaker performance evaluation. The life of a circuit breaker is largely determined by the life of its contacts. Therefore, mechanical characteristics and contact life prediction are the main contents of circuit breaker status monitoring. For a long time, the judgment of the operating status of high-voltage circuit breakers at home and abroad has been achieved through regular maintenance or power outage preventive tests, and static evaluation has been carried out based on relevant standards and expert operating experience. However, practice has proved that high-voltage circuit breakers that have passed static evaluation cannot guarantee their safe and reliable operation in actual applications. Therefore, it is very necessary to provide an online monitoring device and method for the operating status of circuit breakers based on distribution automation, which has efficient online monitoring, realizes remote online monitoring, and has accurate, reliable and high-precision evaluation. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide an online monitoring device and method for the operation status of a circuit breaker based on distribution automation, which has the advantages of efficient online monitoring, realizing remote online monitoring, and accurate, reliable and high-precision evaluation.

[0004] The object of the present invention is achieved as follows: an online monitoring device for the operating status of a circuit breaker based on distribution automation, which includes a sensor and a conditioning circuit, an A / D conversion and microprocessing module and a processor, wherein the sensor and conditioning circuit include a sensor and a signal conditioning circuit connected to the output end of the sensor; the A / D conversion and microprocessing module includes an analog-to-digital conversion module and a microprocessing module connected to the output end of the signal conditioning circuit; the sensor includes a displacement sensor, an acceleration sensor, a Hall current sensor and a pressure sensor.

[0005] The acceleration sensor adopts a 34208A three-axis sensor; the analog-to-digital conversion module adopts an AD7606 conversion module; the microprocessor module adopts an STM32F407 module; and the processor adopts an ARM Cortex chip.

[0006] An online monitoring system for the operation status of a circuit breaker based on distribution automation comprises a sensor fusion module, an integrated control module, a signal processing module and an online monitoring device for the operation status of a circuit breaker based on distribution automation as described in any one of claims 1 to 2; the sensor fusion module is connected to the sensor and the conditioning circuit; the signal processing module is connected to the A / D conversion and microprocessing module; and the integrated control module is connected to the processor.

[0007] The sensor fusion module adopts the LM1117 low-dropout voltage regulator to realize dynamic visualization of circuit breaker operation monitoring data and provide current limiting and thermal protection functions; the integrated control module adopts the TMS32010 digital signal processing chip to realize data processing during the operation of the circuit breaker; the signal processing module adopts the TRF7960 reader / writer chip to realize the reading and writing processing of monitoring data during the startup of the circuit breaker and realize three-dimensional visualization control during the operation of the circuit breaker.

[0008] The system consists of a data acquisition layer, a network communication layer and an application management layer; the data acquisition layer realizes circuit breaker operation data acquisition, status collection, analog-to-digital conversion, signal conditioning, serial port transmission, and data preprocessing; the application management layer is deployed in the distribution automation master station III area, and realizes online evaluation of the circuit breaker operation status in the entire network system by collecting the data acquisition layer status quantity; the application management layer consists of four modules: circuit breaker information management, circuit breaker status evaluation, circuit breaker fault diagnosis, and circuit breaker life prediction.

[0009] The circuit breaker status evaluation specifically includes the following steps:

[0010] S1: Use intelligent pattern matching algorithm to analyze the current waveform of the circuit breaker opening and closing coils and evaluate the mechanical characteristics of the circuit breaker;

[0011] S2: Extract the circuit breaker breaking current from the distribution automation terminal telemetered current according to the start time of the opening and closing coil current change; use the opening and closing coil current, telemetered current change, and telemetered current to comprehensively calculate the circuit breaker arcing time; based on the breaking current and arcing time, use the weighted evaluation algorithm to evaluate the electrical life of the circuit breaker contacts;

[0012] S3: Each time during the "remote control" operation of the circuit breaker in the distribution automation system, or during the change of the "remote signaling" quantity, the mechanical performance of the circuit breaker is graded and evaluated synchronously, and a maintenance strategy is given.

[0013] The circuit breaker mechanical characteristic evaluation in S1 is specifically as follows: the circuit breaker mechanical characteristic evaluation based on the opening and closing coil current analysis is adopted. When the "remote signal" quantity changes, the circuit breaker mechanical characteristic analysis and evaluation program starts, and the intelligent pattern matching algorithm is adopted to analyze the collected opening and closing coil current, and evaluate whether the electromagnet core mechanism has the phenomenon of jamming, deformation, tripping failure, etc.; evaluate the movement of the transmission part of the circuit breaker operating mechanism; evaluate the type and development trend of some mechanical defects of the circuit breaker; adopt the statistical pattern recognition algorithm to realize the comparison and classification of the opening and closing waveform with the waveform library, and according to the characteristic vector X measured by the pattern i =(x i1 ,x i2 ,...,x id ) T , i = 1, 2, ..., N, classify a given pattern into C classes ω1, ω2, ..., ω c Then the classification is determined based on the distance function between the patterns, where N is the number of sample points and d is the number of sample features.

[0014] The circuit breaker life prediction and evaluation is specifically as follows: by monitoring the breaking current breaking times, arcing time parameters, and accumulating the contact wear through mathematical algorithm analysis, the contact electrical life can be evaluated, and the remaining life of the contact can be predicted as: Where, Q is the electrical wear of the contact; I i is the i-th breaking current; t i is the arcing time of the i-th interruption.

[0015] A method for online monitoring of the operating status of a circuit breaker based on distribution automation, wherein the method controls the online monitoring device for the operating status of a circuit breaker based on distribution automation as described above through the online monitoring system for the operating status of a circuit breaker based on distribution automation as described above to realize comprehensive operating status evaluation of a high-voltage circuit breaker, wherein the method adopts an evaluation method for the operating status of a high-voltage circuit breaker combining a hierarchical analysis method, entropy weight theory and fuzzy comprehensive evaluation, and comprises the following steps:

[0016] Step 1: Fuzzy comprehensive evaluation;

[0017] Step 2: Determination of the weights of evaluation factors;

[0018] Step 3: Evaluate the model;

[0019] Step 4: Determination of the membership of the evaluation factors.

[0020] The fuzzy comprehensive evaluation in step 1 includes the following steps:

[0021] Step 1.1: Establish a set of evaluation factors: The factor set is a collection of factors that affect the evaluation object.j Indicates that U j =(u1,u2,...,u n ), each element u i That is, it represents various influencing factors;

[0022] Step 1.2: Establish a set of evaluation levels: The level set is a set of various possible evaluation results that the evaluator may make on the evaluation object, represented by V, that is, V = (v1, v2, v3, ..., v m );

[0023] Step 1.3: Establish a weight set: The weight is the importance of each factor in the evaluation target. Each factor should be given a corresponding weight. i =(i=1,2,3,...,n); the set of weights A=(a1,a2,...,a n ), called the factor weight set; the weight coefficient must satisfy the normalization condition:

[0024] Step 1.4: Fuzzy evaluation matrix: For the evaluation object, calculate the i-th factor u in the factor set i Make a judgment, corresponding to the jth element v in the evaluation level set j The degree of membership is r ij , then according to the i-th element u i The judgment result can be obtained by using the fuzzy set R i =(r i1 ,r i2 ,r i3 ,...,r in ) indicates that R i It is called a single factor evaluation set; the matrix composed of the membership degree of each factor evaluation set as the row It is called the fuzzy judgment matrix;

[0025] Step 1.5: Fuzzy comprehensive evaluation: evaluation results in is a fuzzy operator; b j It is called the first-level fuzzy comprehensive evaluation result, which means the membership of the evaluation object to the jth level in the evaluation level set when a comprehensive evaluation is performed according to all levels of the factors in U; ​​according to the maximum membership principle, the evaluation level to which the evaluated object belongs is determined.

[0026] Beneficial effects of the invention: The invention is an online monitoring device and method for the operation status of a circuit breaker based on distribution automation. In use, the device of the invention applies various sensors on the circuit breaker, supplemented by a signal conversion module, to remotely transmit the operation status and problem defects of the circuit breaker, thereby realizing efficient online monitoring; the device of the invention uses a parallel peripheral interface to connect to the circuit breaker, which can monitor the dynamic changes of the circuit breaker operation data, and at the same time perform early warning processing on the monitored abnormal data; the system of the invention makes full use of the distribution automation terminal, configures sensors in the distribution circuit breaker, and combines the communication channel of the automation terminal, remote The invention can realize remote online monitoring of the mechanical performance and contact life of the distribution circuit breaker by measuring and remote signaling, and improve the pertinence of equipment maintenance; the method of the invention uses a method for evaluating the operating status of a high-voltage circuit breaker by combining a hierarchical analysis method, entropy weight theory and fuzzy comprehensive evaluation, firstly, the membership function of each factor is determined by fuzzy mathematics, and then the comprehensive weight of the operating parameter index of the high-voltage circuit breaker is determined by the hierarchical analysis method and weight theory, and finally, the comprehensive operating status of the high-voltage circuit breaker is obtained by combining the index weight with the evaluation matrix through fuzzy operation; the invention has the advantages of efficient online monitoring, remote online monitoring, accurate and reliable evaluation and high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a block diagram of the device composition of the present invention.

[0028] Figure 2 It is a system block diagram of the present invention.

[0029] Figure 3 It is a system structure diagram of the present invention.

[0030] Figure 4 This is a flow chart of the distribution circuit breaker operating status evaluation of the present invention.

[0031] Figure 5 It is a schematic diagram of the circuit breaker opening and closing coil current waveform pattern matching analysis algorithm of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings.

[0033] Example 1

[0034] like Figure 1-5 As shown, an online monitoring device for the operation status of a circuit breaker based on distribution automation includes a sensor and a conditioning circuit, an A / D conversion and microprocessing module and a processor. The sensor and conditioning circuit include a sensor and a signal conditioning circuit connected to the output end of the sensor; the A / D conversion and microprocessing module includes an analog-to-digital conversion module and a microprocessing module connected to the output end of the signal conditioning circuit; the sensor includes a displacement sensor, an acceleration sensor, a Hall current sensor and a pressure sensor.

[0035] The acceleration sensor adopts a 34208A three-axis sensor; the analog-to-digital conversion module adopts an AD7606 conversion module; the microprocessor module adopts an STM32F407 module; and the processor adopts an ARM Cortex chip.

[0036] In this embodiment, ① the movement amount of the transmission rod of the displacement sensor can be converted into a load voltage, and the signal is amplified by the amplifier element Im324, processed by the analog-to-digital conversion module, and calculated by the single-chip microcomputer to finally form a displacement-time characteristic curve, which provides data support for the characteristic fitting of other sensors in the later stage; ② the data communication between the acceleration sensor and the signal conditioning circuit can amplify the weak vibration signal generated when the circuit breaker fails and transmit it to the output end of the signal conditioning circuit, and then establish a stable transmission connection with the STM32F407 through the analog-to-digital conversion module, so as to obtain the characteristic fitting curve of the vibration signal. By comparing the characteristic curve under normal conditions, the operating state of the circuit breaker can be intuitively judged; under normal circumstances, the response charge of the sensor will increase significantly after sensing a weak vibration, and with the increase of the number and frequency of vibrations, the charge amount will also increase continuously, showing a positive proportional relationship. Amplifying the charge amount and performing analog-to-digital conversion can obtain a clear fault characteristic curve; ③ the Hall current sensor can be the most To maximize the sensitivity to the current operation dynamics of the circuit breaker, the Hall current sensor can capture weak current signals, amplify the potential difference generated by the current on the resistor through the pre-arranged dedicated signal acquisition module, and optimize the signal through the filter group to obtain the data stream before the digital-to-analog conversion, and transmit the data stream to the modulation circuit for data value simulation calculation, and finally fit the calculated value with the actual situation to obtain the real-time operation dynamics of the current; ④ The pressure sensor can monitor the pressure generated by the closed contact during the line closed loop process through the circuit breaker contact, and can determine the closing stability of the contact and the line, and avoid the circuit breaker ignition failure and other serious faults caused by the non-tight contact of the circuit breaker; after the sensor completes the signal acquisition, the accurate calculation value can be obtained through the extraction and analysis of the conditioning circuit, and then the sensor characteristic curve is fitted. The specific working state of the circuit breaker can be determined by real-time monitoring of the fitting status of the characteristic curve, and then the fault and failure of the circuit breaker can be judged.

[0037] The present invention is an online monitoring device and method for the operating status of a circuit breaker based on power distribution automation. In use, the device of the present invention applies various sensors on the circuit breaker, assisted by a signal conversion module, to remotely transmit the operating status and problem defects of the circuit breaker, thereby realizing efficient online monitoring; the device of the present invention uses a parallel peripheral interface to connect with the circuit breaker, can monitor the dynamic changes of the circuit breaker operating data, and at the same time perform early warning processing on the monitored abnormal data; the present invention has the advantages of efficient online monitoring, remote online monitoring, and accurate, reliable and high-precision evaluation.

[0038] Example 2

[0039] like Figure 1-5 As shown, the online monitoring system for the operation status of a circuit breaker based on distribution automation includes a sensor fusion module, an integrated control module, a signal processing module and the online monitoring device for the operation status of a circuit breaker based on distribution automation as described above; the sensor fusion module is connected to the sensor and the conditioning circuit; the signal processing module is connected to the A / D conversion and microprocessing module; and the integrated control module is connected to the processor.

[0040] The sensor fusion module adopts the LM1117 low-dropout voltage regulator to realize dynamic visualization of circuit breaker operation monitoring data and provide current limiting and thermal protection functions; the integrated control module adopts the TMS32010 digital signal processing chip to realize data processing during the operation of the circuit breaker; the signal processing module adopts the TRF7960 reader / writer chip to realize the reading and writing processing of monitoring data during the startup of the circuit breaker and realize three-dimensional visualization control during the operation of the circuit breaker.

[0041] The system consists of a data acquisition layer, a network communication layer and an application management layer; the data acquisition layer realizes circuit breaker operation data acquisition, status collection, analog-to-digital conversion, signal conditioning, serial port transmission, and data preprocessing; the application management layer is deployed in the distribution automation master station III area, and realizes online evaluation of the circuit breaker operation status in the entire network system by collecting the data acquisition layer status quantity; the application management layer consists of four modules: circuit breaker information management, circuit breaker status evaluation, circuit breaker fault diagnosis, and circuit breaker life prediction.

[0042] In this embodiment, the acquisition parameters of the data acquisition layer specifically include: ① connecting a Hall current sensor in the circuit breaker opening and closing coil loop to monitor the circuit breaker opening and closing coil current, and connecting to the distribution automation terminal through the serial port; ② the distribution automation terminal "remote signal" monitoring quantity; ③ the distribution automation terminal "remote measurement" current monitoring quantity; the data acquisition layer connects the collected operation data and status quantity to the ONU through the serial port data line, and the ONU transmits the data to the master station through the network communication layer for unified analysis and release; circuit breaker information management at the application management layer: storage and processing of basic information of circuit breakers and real-time status monitoring Data, such as remote signal position change information, real-time primary current, opening and closing current information, etc.; Circuit breaker mechanical characteristics evaluation: Use the real-time monitored remote signal position change information, real-time primary current, opening and closing current information, combined with historical data, to evaluate the health of the circuit breaker; Circuit breaker fault diagnosis: When a circuit breaker fails, use the monitoring historical information and health data to trace the fault scenario, and provide the possible causes and maintenance strategies for the circuit breaker failure; Circuit breaker degradation trend prediction: Use the primary system current when the circuit breaker is opening and closing, as well as the overcurrent condition of the primary side of the circuit breaker, and use the weighted evaluation algorithm to predict the circuit breaker degradation;

[0043] The circuit breaker status evaluation specifically includes the following steps:

[0044] S1: Use intelligent pattern matching algorithm to analyze the current waveform of the circuit breaker opening and closing coils and evaluate the mechanical characteristics of the circuit breaker;

[0045] S2: Extract the circuit breaker breaking current from the distribution automation terminal telemetered current according to the start time of the opening and closing coil current change; use the opening and closing coil current, telemetered current change, and telemetered current to comprehensively calculate the circuit breaker arcing time; based on the breaking current and arcing time, use the weighted evaluation algorithm to evaluate the electrical life of the circuit breaker contacts;

[0046] S3: Each time during the "remote control" operation of the circuit breaker in the distribution automation system, or during the change of the "remote signaling" quantity, the mechanical performance of the circuit breaker is graded and evaluated synchronously, and a maintenance strategy is given.

[0047] The circuit breaker mechanical characteristic evaluation in S1 is specifically as follows: the circuit breaker mechanical characteristic evaluation is performed based on the analysis of the opening and closing coil current. When the "remote signal" quantity changes, the circuit breaker mechanical characteristic analysis and evaluation program starts, and the intelligent pattern matching algorithm is used to analyze the collected opening and closing coil current, and evaluate whether the electromagnet core mechanism has stuck, deformed, tripped, etc.; evaluate the movement of the transmission part of the circuit breaker operating mechanism; and evaluate the types and development trends of some mechanical defects of the circuit breaker; Figure 5The algorithm is the flow of the circuit breaker opening and closing coil current waveform pattern matching analysis algorithm. The algorithm first relies on the establishment of the opening and closing coil waveform library, including the normal waveform library of each type of circuit breaker, the historical waveform library of the tested circuit breaker, and various defect waveform libraries; the pattern recognition algorithm automatically completes the comparison and classification of various features of the tested waveform and the above three waveforms, thereby realizing waveform analysis; the statistical pattern recognition algorithm is used to realize the comparison and classification of the opening and closing waveform and the waveform library, and the characteristic vector X measured according to the pattern is obtained. i =(x i1 ,x i2 ,...,x id ) T , i = 1, 2, ..., N, classify a given pattern into C classes ω1, ω2, ..., ω c Then the classification is determined based on the distance function between the patterns, where N is the number of sample points and d is the number of sample features.

[0048] Pattern recognition algorithms such as Figure 5 As shown, it includes preprocessing, feature extraction and selection, feature curve generation, feature matching and comparative analysis. By quantifying and classifying the differences between the tested opening and closing coil waveform and the normal waveform, historical waveform, and defect waveform, the mechanical state of the circuit breaker is evaluated. By matching with the defect waveform characteristics, the mechanical defects and causes can be evaluated.

[0049] The circuit breaker life prediction and evaluation is specifically as follows: the electrical life of the circuit breaker is another important parameter in the online monitoring of the circuit breaker. The main factor affecting the electrical life is the electrical wear of the contact, and the electrical wear of the contact depends on the breaking current (arcing current) and arcing time, the structure of the arc extinguishing chamber, and the movement speed of the contact. By monitoring the breaking current, breaking times, arcing time and other parameters, and analyzing the accumulated contact wear by mathematical algorithms, the electrical life of the contact can be evaluated, and the remaining life of the contact can be predicted as follows: Where, Q is the electrical wear of the contact; I i is the i-th breaking current; t i is the arcing time of the i-th breaking, which is obtained by comprehensive calculation of the closing and opening coil current, the change of the telemetered current, and the telesignaling quantity.

[0050] The present invention is an online monitoring device and method for the operation status of a circuit breaker based on distribution automation. In use, the system of the present invention makes full use of the distribution automation terminal, configures sensors in the distribution circuit breaker, and combines the communication channel, telemetry, and telesignaling of the automation terminal to achieve remote online monitoring of the mechanical properties and contact life of the distribution circuit breaker, thereby improving the pertinence of equipment maintenance. The present invention has the advantages of efficient online monitoring, remote online monitoring, and accurate, reliable, and high-precision evaluation.

[0051] Example 3

[0052] like Figure 1-5 As shown, a method for online monitoring of the operating status of a circuit breaker based on distribution automation is provided. The method controls the online monitoring device for the operating status of a circuit breaker based on distribution automation as described above to realize comprehensive operating status evaluation of a high-voltage circuit breaker through the online monitoring system for the operating status of a circuit breaker based on distribution automation as described above. The method adopts an evaluation method for the operating status of a high-voltage circuit breaker combining the analytic hierarchy process, the entropy weight theory and the fuzzy comprehensive evaluation, and comprises the following steps:

[0053] Step 1: Fuzzy comprehensive evaluation;

[0054] In this embodiment, step 1 includes the following steps:

[0055] Step 1.1: Establish a set of evaluation factors: The factor set is a collection of factors that affect the evaluation object. j Indicates that U j =(u1,u2,...,u n ), each element u i That is, it represents various influencing factors;

[0056] Step 1.2: Establish a set of evaluation levels: The level set is a set of various possible evaluation results that the evaluator may make on the evaluation object, represented by V, that is, V = (v1, v2, v3, ..., v m );

[0057] Step 1.3: Establish a weight set: The weight is the importance of each factor in the evaluation target. Each factor should be given a corresponding weight. i =(i=1,2,3,...,n); the set of weights A=(a1,a2,...,a n ), called the factor weight set; the weight coefficient must satisfy the normalization condition:

[0058] Step 1.4: Fuzzy evaluation matrix: For the evaluation object, calculate the i-th factor u in the factor set i Make a judgment, corresponding to the jth element v in the evaluation level set j The degree of membership is r ij , then according to the i-th element u i The judgment result can be obtained by using the fuzzy set R i =(r i1 ,r i2 ,r i3 ,...,r in ) indicates that R i It is called a single factor evaluation set; the matrix composed of the membership degree of each factor evaluation set as the row It is called the fuzzy judgment matrix;

[0059] Step 1.5: Fuzzy comprehensive evaluation: evaluation results in is a fuzzy operator; b j It is called the first-level fuzzy comprehensive evaluation result, which means the membership of the evaluation object to the jth level in the evaluation level set when a comprehensive evaluation is performed according to all levels of the factors in U; ​​according to the maximum membership principle, the evaluation level to which the evaluated object belongs is determined.

[0060] Step 2: Determination of the weights of evaluation factors;

[0061] In this embodiment, step 2 includes the following steps:

[0062] Step 2.1: When determining subjective weights using the AHP, first, a hierarchical model is established to determine the target and evaluation factor set; second, a judgment matrix is ​​constructed, which represents the relative importance of the factors related to a factor at the previous level; the elements are compared pairwise and scaled using a 1-9 scale. The meaning of the scale is shown in Table 1;

[0063] Table 1 Judgment matrix scale and meaning

[0064]

[0065] Then the importance ranking is calculated. It is based on the AU judgment matrix to find the eigenvector corresponding to the largest eigenvalue. The eigenvector is the importance ranking of each evaluation factor, that is, the weight distribution. Finally, the consistency test can be found through the consistency formula: In the formula, C R is the random consistency ratio of the judgment matrix; C I is the general consistency index of the judgment matrix, R I is the average random consistency index of the judgment matrix. For the 1-9 order judgment matrix, R I The values ​​are listed in Table 2;

[0066] Table 2 Average random consistency index values

[0067]

[0068] When C R When <0.1, the judgment matrix is ​​considered to have satisfactory consistency, indicating that the weight distribution is reasonable. Otherwise, the judgment matrix needs to be adjusted until satisfactory consistency is achieved;

[0069] Step 2.2: In information theory, information is a measure of the degree of order in a system, and information is a measure of the degree of disorder in a system. The two are equal in absolute value but opposite in sign. When a system may be in several different states, the probability of each state occurring is p.i (i=1,2,...,m), the entropy of the system is defined as: Obviously, when p i =1 / m, (i=1,2,...,m), that is, when the probabilities are equal, the entropy reaches its maximum value: E max = lnm, there are m items to be evaluated and n evaluation indicators, forming the original indicator data matrix R = (r ij ) mn For j = 1, 2, ..., n, the information entropy is: In the formula, It can be seen that if the entropy E of a certain indicator j The smaller it is, the greater the variation of its index value, the more information it provides, the greater its role in the comprehensive evaluation, and the greater its weight should be. j The larger the value is, the smaller the variation of the index value is, the less information is provided, the smaller the role it plays in the comprehensive evaluation is, and the smaller its weight is. In the specific analysis process, the weight of each index can be calculated based on the variation of each index value using entropy, and all indexes can be weighted using the weight of each index to obtain a more objective evaluation result.

[0070] Step 3: Evaluate the model;

[0071] In this embodiment, the index system is shown in Table 3;

[0072] Table 3 High voltage circuit breaker operating status evaluation index system

[0073]

[0074]

[0075] Step 4: Determination of the membership of the evaluation factors.

[0076] In this embodiment, the semi-trapezoidal distribution function and the trigonometric function are used as the membership function, and the parameters contained in the distribution are established according to the measured data to determine the membership. The evaluation index factor set X T ={x1,x2,...,x m}, evaluation level standard V = {v1,v2,...,v m}, let v j and v j+1 For two adjacent levels of standards, and v j+1 >v j , then the membership function is: Calculate the degree of membership of the evaluation index to the evaluation level and generate the membership function:

[0077] The invention discloses an online monitoring device and method for the operation state of a circuit breaker based on power distribution automation. In use, the method of the invention uses a method for evaluating the operation state of a high-voltage circuit breaker by combining a hierarchical analysis method, an entropy weight theory and a fuzzy comprehensive evaluation. First, the membership function of each factor is determined by fuzzy mathematics. Secondly, the comprehensive weight of the operation parameter index of the high-voltage circuit breaker is determined by the hierarchical analysis method and the weight theory. Finally, the comprehensive operation state of the high-voltage circuit breaker is obtained by combining the index weight with the evaluation matrix for fuzzy operation. The method of the invention proposes a multi-level fuzzy comprehensive evaluation model for the operation state of the high-voltage circuit breaker in combination with the actual operation state of the high-voltage circuit breaker. The electrical characteristics, mechanical characteristics, insulation characteristics, environmental characteristics and appearance conditions of the high-voltage circuit breaker are selected as the contents of the comprehensive evaluation of the operation state of the high-voltage circuit breaker. The factors are evaluated and calculated respectively to find out the weak links of the operation state, which can effectively reduce premature or unnecessary power outage tests and maintenance, reduce the maintenance workload, and reduce the maintenance cost. At the same time, the pertinence of the maintenance can be improved during the maintenance. The invention has the advantages of efficient online monitoring, remote online monitoring, and accurate, reliable and high-precision evaluation.

Claims

1. An online monitoring device for circuit breaker operation status based on distribution automation, which includes a sensor and conditioning circuit, an A / D conversion and microprocessing module and a processor, and is characterized by: The sensor and conditioning circuit include a sensor and a signal conditioning circuit connected to the output end of the sensor; the A / D conversion and microprocessing module include an analog-to-digital conversion module and a microprocessing module connected to the output end of the signal conditioning circuit; the sensor includes a displacement sensor, an acceleration sensor, a Hall current sensor and a pressure sensor.

2. The online monitoring device for circuit breaker operation status based on distribution automation according to claim 1, characterized in that: The acceleration sensor adopts a 34208A three-axis sensor; the analog-to-digital conversion module adopts an AD7606 conversion module; the microprocessor module adopts an STM32F407 module; and the processor adopts an ARM Cortex chip.

3. The circuit breaker operation status online monitoring system based on distribution automation is characterized by: It comprises a sensor fusion module, an integrated control module, a signal processing module and an online monitoring device for the operation status of a circuit breaker based on distribution automation as described in any one of claims 1 to 2; the sensor fusion module is connected to the sensor and the conditioning circuit; the signal processing module is connected to the A / D conversion and microprocessing module; the integrated control module is connected to the processor.

4. The online monitoring system for circuit breaker operation status based on distribution automation according to claim 3, characterized in that: The sensor fusion module adopts the LM1117 low-dropout voltage regulator to realize dynamic visualization of circuit breaker operation monitoring data and provide current limiting and thermal protection functions; the integrated control module adopts the TMS32010 digital signal processing chip to realize data processing during the operation of the circuit breaker; the signal processing module adopts the TRF7960 reader / writer chip to realize the reading and writing processing of monitoring data during the startup of the circuit breaker and realize three-dimensional visualization control during the operation of the circuit breaker.

5. The online monitoring system for circuit breaker operation status based on distribution automation according to claim 3, characterized in that: The system consists of a data acquisition layer, a network communication layer and an application management layer; the data acquisition layer realizes circuit breaker operation data acquisition, status collection, analog-to-digital conversion, signal conditioning, serial port transmission, and data preprocessing; the application management layer is deployed in the distribution automation master station III area, and realizes online evaluation of the circuit breaker operation status in the entire network system by collecting the data acquisition layer status quantity; the application management layer consists of four modules: circuit breaker information management, circuit breaker status evaluation, circuit breaker fault diagnosis, and circuit breaker life prediction.

6. The online monitoring system for circuit breaker operation status based on distribution automation according to claim 5, characterized in that: The circuit breaker status evaluation specifically includes the following steps: S1: Use intelligent pattern matching algorithm to analyze the current waveform of the circuit breaker opening and closing coils and evaluate the mechanical characteristics of the circuit breaker; S2: Extract the circuit breaker breaking current from the distribution automation terminal telemetered current according to the start time of the opening and closing coil current change; use the opening and closing coil current, telemetered current change, and telemetered current to comprehensively calculate the circuit breaker arcing time; based on the breaking current and arcing time, use the weighted evaluation algorithm to evaluate the electrical life of the circuit breaker contacts; S3: Each time during the "remote control" operation of the circuit breaker in the distribution automation system, or during the change of the "remote signaling" quantity, the mechanical performance of the circuit breaker is graded and evaluated synchronously, and a maintenance strategy is given.

7. The online monitoring system for circuit breaker operation status based on distribution automation according to claim 6, characterized in that: The mechanical characteristic evaluation of the circuit breaker in S1 is specifically as follows: the mechanical characteristic evaluation of the circuit breaker based on the analysis of the opening and closing coil current is adopted. When the "remote signal" quantity changes, the mechanical characteristic analysis and evaluation program of the circuit breaker starts, and the intelligent pattern matching algorithm is adopted to analyze the collected opening and closing coil current, and evaluate whether the electromagnet core mechanism has the phenomenon of jamming, deformation, tripping failure, etc.; evaluate the movement of the transmission part of the circuit breaker operating mechanism; evaluate the type and development trend of some mechanical defects of the circuit breaker; adopt the statistical pattern recognition algorithm to realize the comparison and classification of the opening and closing waveform with the waveform library, and according to the characteristic vector X measured by the pattern i =(x i1 ,x i2 ,...,x id ) T , i = 1, 2, ..., N, classify a given pattern into C classes ω1, ω2, ..., ω c Then the classification is determined based on the distance function between the patterns, where N is the number of sample points and d is the number of sample features.

8. The online monitoring system for circuit breaker operation status based on distribution automation according to claim 5, characterized in that: The circuit breaker life prediction and evaluation is specifically as follows: by monitoring the breaking current breaking times, arcing time parameters, and accumulating the contact wear through mathematical algorithm analysis, the contact electrical life can be evaluated, and the remaining life of the contact can be predicted as: Where, Q is the electrical wear of the contact; I i is the i-th breaking current; t i is the arcing time of the i-th interruption.

9. A method for online monitoring of circuit breaker operating status based on distribution automation, characterized in that: The method realizes comprehensive operation status evaluation of high-voltage circuit breakers by controlling the online monitoring system for operation status of circuit breakers based on distribution automation as claimed in any one of claims 1 to 2 through the online monitoring system for operation status of circuit breakers based on distribution automation as claimed in any one of claims 3 to 8. The method adopts an evaluation method for the operation status of high-voltage circuit breakers combining hierarchical analysis method, entropy weight theory and fuzzy comprehensive evaluation, and comprises the following steps: Step 1: Fuzzy comprehensive evaluation; Step 2: Determination of the weights of evaluation factors; Step 3: Evaluate the model; Step 4: Determination of the membership of the evaluation factors.

10. The method for online monitoring of circuit breaker operation status based on distribution automation according to claim 9, characterized in that: The fuzzy comprehensive evaluation in step 1 includes the following steps: Step 1.1: Establish a set of evaluation factors: The factor set is a collection of factors that affect the evaluation object. j Indicates that U j =(u1,u2,...,u n ), each element u i That is, it represents various influencing factors; Step 1.2: Establish a set of evaluation levels: The level set is a set of various possible evaluation results that the evaluator may make on the evaluation object, represented by V, that is, V = (v1, v2, v3, ..., v m ); Step 1.3: Establish a weight set: The weight is the importance of each factor in the evaluation target. Each factor should be given a corresponding weight. i =(i=1,2,3,...,n); the set of weights A=(a1,a2,...,a n ), called the factor weight set; the weight coefficient must satisfy the normalization condition: Step 1.4: Fuzzy evaluation matrix: For the evaluation object, calculate the i-th factor u in the factor set i Make a judgment, corresponding to the jth element v in the evaluation level set j The degree of membership is r ij , then according to the i-th element u i The judgment result can be obtained by using the fuzzy set R i =(r i1 ,r i2 ,r i3 ,...,r in ) indicates that R i It is called a single factor evaluation set; the matrix composed of the membership degree of each factor evaluation set as the row It is called the fuzzy judgment matrix; Step 1.5: Fuzzy comprehensive evaluation: evaluation results in is a fuzzy operator; b j It is called the first-level fuzzy comprehensive evaluation result, which means the membership of the evaluation object to the jth level in the evaluation level set when a comprehensive evaluation is performed according to all levels of the factors in U; ​​according to the maximum membership principle, the evaluation level to which the evaluated object belongs is determined.

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