Circuit break monitoring device and method for electrical safety protection

Abstract

The invention relates to the technical field of circuit breaker monitoring, in particular to an open circuit monitoring device and method for electrical safety protection, and the method comprises the steps: collecting a vibration signal, an opening and closing coil current signal and an environment parameter of a circuit breaker during each detection in a working process; calculating an environment disturbance coefficient according to the relationship between the monitoring signal and the environment change; calculating a time sequence stability coefficient according to the time sequence change characteristic of the monitoring signal; based on the environment disturbance coefficient and the time sequence stability coefficient, constructing a step length for carrying out adaptive filtering on the signals so as to carry out adaptive filtering processing on the vibration signals and the current signals; and circuit breaker fault monitoring is carried out based on the filtered signal. According to the method, the adaptive filtering step length of the signal is adjusted, so that environmental disturbance and excessive filtering are eliminated, and enough details in the signal are reserved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit breaker monitoring, in particular to a circuit breaker monitoring device and method for electrical safety protection. BACKGROUND

[0002] As a key infrastructure, the safe and stable operation of the power system is particularly important, and the circuit breaker, as an important electrical safety protection device, plays a crucial role in the normal operation of the power system. It not only effectively prevents safety accidents caused by electrical faults such as overload and short circuit, but also quickly cuts off the circuit in abnormal conditions to ensure safety and reduce losses. However, the circuit breaker itself may also have various faults due to long-term use or external factors, such as mechanical component wear, poor contact, insulation aging, etc. If these problems are not discovered and addressed in a timely manner, they will pose a serious threat to the safety of the entire power system. Therefore, how to efficiently and accurately monitor the working state of the circuit breaker has become an important issue for improving the reliability of the power system, especially for monitoring mechanical faults of the operating mechanism.

[0003] Mechanical failure of the operating mechanism is one of the most common faults of the circuit breaker, which usually causes changes in the movement mechanism of the mechanical transmission part, and then causes fluctuations in characteristic parameters such as vibration signals and closing and opening coil current signals. The existing technology achieves fault diagnosis of the circuit breaker by analyzing the vibration signals and current signals. However, the existing technology also has a major drawback. When analyzing the vibration signals and current signals, only the fluctuations of the signals themselves are considered, while the potential impact of environmental changes on the signals is often ignored. Environmental changes can also affect the mechanical movement process of the circuit breaker, causing non-fault fluctuations in the vibration signals or current signals. If the fault diagnosis of the circuit breaker is based solely on the fluctuations of the signals themselves, it will undoubtedly increase the misdiagnosis of the circuit breaker fault. Therefore, there is an urgent need for a more comprehensive circuit breaker fault detection method to improve the accuracy of circuit breaker fault detection and ensure the safe and stable operation of the power system. SUMMARY

[0004] To solve the above technical problems, the present application provides a circuit breaker monitoring device and method for electrical safety protection, and the technical solution adopted is as follows: In a first aspect, one embodiment of the present application provides a circuit breaker monitoring method for electrical safety protection, which comprises the following steps: Collecting vibration signals, closing and opening coil current signals, and environmental parameters of the circuit breaker during each detection; the environmental parameters include environmental temperature and humidity; The cross-correlation analysis method is used to analyze the vibration lags between the vibration signals and the current signals of all previous detections and the corresponding vibration signals and current signals of the first detection before each detection; and the environmental disturbance coefficients of each detection are calculated in combination with the correlation between the fluctuation characteristics of the vibration signals and the current signals and the environmental parameters; The autocorrelation coefficients of the vibration signals and the current signals of all previous detections before each detection are analyzed; the autocorrelation coefficients of the two kinds of signals obtained by all previous detections before each detection are linearly fitted respectively to analyze the trend changes of the fitting straight lines, and the time sequence stability coefficients of each detection are calculated; The vibration signals and the current signals of the first detection are taken as the expected signals, the step of adaptive filtering of the signals is constructed by using the environmental disturbance coefficients and the time sequence stability coefficients, so as to filter the vibration signals and the current signals of each subsequent detection; and the circuit breaker fault monitoring is performed based on the filtered signals.

[0005] Preferably, the method for collecting the vibration signals and the closing and opening coil current signals in each detection is as follows: the vibration signals during the operation of the circuit breaker are collected, the vibration signals are amplified by using a charge amplifier, and the amplified signals are input into an oscilloscope; when the vibration signals are greater than a preset trigger value, the data of 100 ms before and after the vibration signals are automatically saved, the segment of data is taken as the vibration signals of one detection, and the time range of the segment is taken as the time period of one detection; the closing and opening coil current signals in the time period are taken as the closing and opening coil current signals of the detection.

[0006] Preferably, the environmental parameters are obtained at the last data collection time in the detection time period.

[0007] Preferably, the vibration lags between the vibration signals and the current signals of all previous detections and the corresponding vibration signals and current signals of the first detection before each detection are analyzed; and the environmental disturbance coefficients of each detection are calculated in combination with the correlation between the fluctuation characteristics of the vibration signals and the current signals and the environmental parameters, including: The vibration signals of each detection are formed into a vibration sequence, and the vibration lags between the vibration sequences of all previous detections before each detection and the vibration sequence of the first detection are calculated; The current signals of each detection are formed into a current sequence, and the current lags between the vibration sequences of all previous detections before each detection and the vibration sequence of the first detection are calculated; the trend sequence of the current lag sequence is obtained; The variance of the vibration sequence of each detection is calculated to form a vibration fluctuation sequence; The mean value of the current sequence of each detection is calculated to form a current fluctuation sequence; Obtain the temperature data for each test and all previous tests to form a temperature sequence; Obtain the humidity data for each test and all previous tests to form a humidity sequence; Based on the correlation between the first-order difference sequence of the trend sequence, vibration hysteresis, vibration fluctuation sequence and current fluctuation sequence and the temperature sequence and humidity sequence respectively, the environmental disturbance coefficient of each detection is calculated.

[0008] Preferably, the vibration hysteresis is the hysteresis corresponding to the maximum value of the cross-correlation coefficient when a cross-correlation analysis method is used between two vibration sequences.

[0009] Preferably, the environmental disturbance coefficient at each detection is calculated based on the correlation between the first-order difference sequence of the trend sequence, the vibration hysteresis, the vibration fluctuation sequence, and the current fluctuation sequence and the temperature sequence and the humidity sequence, respectively, including: : It is The environmental disturbance coefficient at the time of the first detection, It is The correlation measure between the temperature series and the vibration lag series at the time of the first detection, 、 It is The correlation measurement between the temperature series, humidity series and vibration fluctuation series at the time of the first detection, It is The mean value of the elements in the first-order difference sequence of the trend sequence of the current hysteresis sequence at the time of the first detection, It is The trend measure of the correlation between the humidity series and the current fluctuation series at each detection time.

[0010] Preferably, the autocorrelation coefficient is used to analyze the autocorrelation coefficients of the vibration signal and the current signal in all the tests before each test; the autocorrelation coefficients of the two signals obtained in all the tests before each test are respectively fitted with a straight line to analyze the trend change of the fitted straight line, and the timing stability coefficient of each test is calculated, including: The vibration sequences of each test and all previous tests are combined into a total vibration sequence according to the test order; Calculate the autocorrelation coefficient of the total vibration sequence as the ordinate, take the detection order as the abscissa, perform straight line fitting, and obtain the fitting straight line of the vibration autocorrelation coefficient; The current sequences of each test and all previous tests are combined into a total current sequence according to the test order; Calculate the autocorrelation coefficient of the total current sequence as the ordinate, take the detection order as the abscissa, perform straight line fitting, and obtain the fitting straight line of the current autocorrelation coefficient; The time series stability coefficient of each detection is calculated using the slope change of the fitting line of the vibration and current autocorrelation coefficients and the average change rate of adjacent elements in the trend sequence of the total vibration sequence and the total current sequence.

[0011] Preferably, the time series stability coefficient at each detection is calculated using the slope change of the fitting straight line of the vibration and current autocorrelation coefficients and the average change rate of adjacent elements in the trend sequence of the total vibration sequence and the total current sequence, including: : It is The timing stability coefficient during the second detection, 、 They are The measurement of the time series change of the vibration signal and current signal during the detection; , 、 Respectively sequence The slope of the fitting line of the vibration autocorrelation coefficient during the first detection, is the average rate of change of adjacent elements in the trend sequence of the total vibration sequence at the i-th detection; , 、 Respectively sequence The slope of the fitting line of the current autocorrelation coefficient during the first detection, is the average change rate of adjacent elements in the trend sequence of the total current sequence at the i-th detection.

[0012] Preferably, the step length for adaptively filtering the signal is constructed as follows: : It is The step size of adaptive filtering of the signal during the second detection, 、 are the preset maximum and minimum step sizes, 、 It is The normalized environmental disturbance coefficient and time series stability coefficient during the first detection, It is a preset smoothing factor that prevents the denominator from reaching zero and controls the transition slope.

[0013] In a second aspect, another embodiment of the present application further provides a circuit breaker monitoring device for electrical safety protection, the device comprising an acquisition module, a filtering module, and a monitoring module; wherein the acquisition module is configured to acquire vibration signals, opening and closing coil current signals, and environmental parameters detected each time the circuit breaker is operating; the environmental parameters include ambient temperature and humidity; The filtering module is configured to analyze the multiple data collected by the monitoring module to realize filtering processing of the vibration signal and the current signal, and the filtering processing realizes the steps in the circuit breaker monitoring method for electrical safety protection. The monitoring module is configured to monitor the circuit breaker failure based on the filtered signals.

[0014] The application has at least the following beneficial effects: The application first calculates an environmental disturbance coefficient according to the monitoring signal and the change of the environment, which quantifies the disturbance of the environmental change to the monitoring signal, thereby helping to enhance the signal filtering quality according to the environmental disturbance and to relatively reduce the misjudgment probability of the operating mechanism mechanical failure; then a time sequence stability coefficient is calculated according to the time sequence change characteristics of the monitoring signal, which quantifies the change trend of the monitoring signal, helps to further distinguish the correlation between the disturbance and the failure of the signal in the subsequent step, and then constructs an adaptive step to adaptively adjust the filtering strength according to the signal condition. Through this method, the characteristics of the monitoring signal are measured according to the environmental disturbance and the time sequence change, and the adaptive filtering step is adjusted according to this, which helps to eliminate certain environmental disturbance and avoid over-filtering, and retains enough detailed characteristics of the signal, thereby making the circuit breaker failure detection result more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0016] Figure 1 A flowchart of the circuit breaker monitoring method for electrical safety protection provided by an embodiment of the application. DETAILED DESCRIPTION

[0017] Embodiment 1 The circuit breaker monitoring method for electrical safety protection provided by an embodiment of the application is specifically described with reference to Figure 1 The method comprises the following steps: Step 1: Collect the vibration signal, the closing and opening coil current signal and the environmental parameter of the circuit breaker at each detection time in the working process.

[0018] The piezoelectric acceleration sensor mounted on the surface of the circuit breaker operating mechanism is used to collect the vibration signal of the circuit breaker during operation, the sampling frequency is set to 100 kHz, the vibration signal is amplified by a charge amplifier, and the amplified signal is input into an oscilloscope, the sampling frequency of the oscilloscope is 25M / s, when the vibration signal is greater than the preset trigger value, the data of 100ms before and after the vibration signal is automatically saved, the segment data is used as the vibration signal of one detection, and the time range of the segment is used as the time period of one detection. It should be noted that the trigger value can be taken as needed, and in this embodiment, the trigger value is 1.5 times the maximum value of the background noise. The extraction of background noise is a common technology in the field of signal processing, and will not be described in detail.

[0019] The circuit breaker dynamic characteristic analyzer is used to collect the closing and opening coil current signal during each detection. Then, the temperature sensor and humidity sensor arranged around the circuit breaker are used to collect the environmental parameters of the circuit breaker during operation, i.e. the environmental temperature and humidity data. Among them, the environmental parameters are obtained at the last data acquisition time of the detection time period in each detection, that is, one environmental temperature data and one environmental humidity data can be obtained in one detection. Finally, each type of collected data is normalized.

[0020] At this point, the vibration signal, closing and opening coil current signal and environmental parameter of the circuit breaker during each detection can be obtained by step one.

[0021] Step two: according to the relationship between the monitoring signal and the environmental change, the environmental disturbance coefficient is calculated; according to the time sequence change characteristics of the monitoring signal, the time sequence stability coefficient is calculated.

[0022] The circuit breaker is very important to ensure the electrical safety of the power grid. As a complex mechanical transmission device, the mechanical failure of the operating structure of the circuit breaker is one of the most common failures, which can seriously affect the operation of the circuit breaker. Therefore, it is necessary to improve the accuracy of the mechanical fault detection of the circuit breaker operating structure. As a complex mechanical transmission device, the circuit breaker will change the motion mechanism when the operating structure has a mechanical failure, and this change will change the vibration of the whole device and the closing and opening coil current signal, so the working state of the circuit breaker is often detected by using the change of the vibration signal and the current signal. However, this method is based on the analysis of the vibration and current signals collected during detection, and does not consider the change of the signals in time dimension, which ignores the influence of environmental change on signal fluctuation, so that the collected detection signal contains environmental disturbance. At the same time, due to the complexity of the working environment of the circuit breaker, the environmental stability is poor, which further affects the accuracy of the mechanical fault detection of the circuit breaker operating structure and increases the probability of misjudgment.

[0023] Step 1: Use the cross-correlation analysis method to analyze the vibration hysteresis between the vibration signals and current signals of all previous tests and the vibration signals and current signals corresponding to the first test; and combine the fluctuation characteristics of the vibration signals and current signals with the correlation between the environmental parameters to calculate the environmental disturbance coefficient of each test.

[0024] For mechanical transmission devices such as circuit breakers, the frictional resistance between the various components in the device has a significant impact on movement and vibration. The current in the opening and closing coils will also change due to changes in the resistance in the device. These will fluctuate to a certain extent under the influence of environmental factors, among which the most influential factors are ambient temperature and humidity. The circuit breaker controls the opening and closing of the switch by converting high- and low-pressure oil circuits. In this process, the oil pressure generated by the high-pressure oil has a significant impact on the response speed and movement of the opening and closing. When the temperature drops, the hydraulic oil's viscosity increases, which also causes increased friction, thereby increasing the oil pressure loss generated by the high-pressure oil, which in turn slows the opening and closing response speed and increases the time. At the same time, in low temperature environments, the viscosity of the lubricating oil between mechanical devices will also increase, and the gaps between components will also increase in low temperature environments, which will increase the vibration of the circuit breaker during mechanical movement.

[0025] When the ambient humidity changes, the degree of oxidation and corrosion of the metal parts of the circuit breaker in a high-humidity environment will increase, causing the resistance to fluctuate and rise. As the metal parts change, the impact of the fluctuation of ambient humidity on the change of resistance becomes more and more obvious, and the correlation becomes stronger and stronger. At the same time, humidity changes will also increase friction between components, and as the metal parts oxidize and corrode, the vibration fluctuations during the opening and closing mechanical movement gradually increase.

[0026] Accordingly, the present application respectively constructs a corresponding vibration sequence from the vibration signal data collected during each circuit breaker opening and closing mechanical movement detection in chronological order, and constructs a corresponding current sequence from the opening and closing coil current data in chronological order.

[0027] First Take the detection of the mechanical movement of the circuit breaker opening and closing as an example, The vibration sequence and The vibration sequence of times is taken as input, and the cross-correlation analysis method is used to output the cross-correlation coefficient corresponding to each hysteresis. The hysteresis corresponding to the maximum cross-correlation coefficient is taken as the vibration hysteresis between the two detections. The value range is . Obtain the first The vibration hysteresis of each test before the first time, all the vibration hysteresis values ​​form a vibration hysteresis sequence from front to back in the order of detection. It should be noted that the first element in the sequence is 0, which means the first time. The vibration hysteresis of the vibration sequence itself is obtained by the second detection. Similarly, by processing the current data in the above manner, the current hysteresis sequence can be obtained. Cross-correlation analysis is a well-known technology and will not be described in detail.

[0028] Then, the variance of each vibration sequence is calculated respectively, and all the variances are combined to form a vibration fluctuation sequence in the detection order; the mean of each current sequence is calculated respectively, and all the means are combined to form a current fluctuation sequence in the detection order.

[0029] Then, the current hysteresis sequence is used as input, and STL time series decomposition is used to output the trend sequence, and the first-order difference sequence of the trend sequence is calculated. STL time series decomposition is a well-known technology and will not be described in detail. The ambient temperature and humidity data of the first test are collected in the order of testing. Temperature sequence and humidity sequence during the first detection.

[0030] Based on the above analysis, calculate the The environmental disturbance coefficient during the first detection is used to measure the degree to which vibration and current signals are affected by environmental changes.

[0031] : It is The environmental disturbance coefficient at the time of the first detection, It is The correlation measure between the temperature series and the vibration lag series at the time of the first detection, 、 It is The correlation measurement between the temperature series, humidity series and vibration fluctuation series at the time of the first detection, It is The mean value of the elements in the first-order difference sequence of the trend sequence of the current hysteresis sequence at the time of the first detection, It is The trend measure of the correlation between the humidity series and the current fluctuation series at each detection time.

[0032] In this embodiment , 、 They are sequence The correlation measurement between the humidity sequence and the current fluctuation sequence detected, In different processing methods, correlation metrics may include but are not limited to Pearson correlation coefficient, Spearman correlation coefficient, and cosine similarity.

[0033] It is understandable that a decrease in temperature may cause the response time of vibration data to slow down and the vibration fluctuation to increase, that is, there is a negative correlation between temperature and vibration response lag and fluctuation, and the stronger the negative correlation, the more it indicates that the abnormal fluctuation of the circuit breaker is mainly caused by the environment; secondly, humidity will increase the resistance of the circuit breaker, thereby causing the current response time to gradually increase, so the current lag shows a clear increasing trend, and as the oxidation of the metal parts of the circuit breaker becomes more and more obvious, the negative correlation between current changes and humidity will be enhanced. At the same time, humidity will also cause larger vibration fluctuations, so the greater the impact of environmental changes on the circuit breaker, the lower the possibility of the circuit breaker being in an abnormal state, and the larger the corresponding environmental disturbance coefficient.

[0034] Step 2: Use the autocorrelation coefficient to analyze the autocorrelation coefficients of the vibration signal and current signal of all the tests before each test; perform linear fitting on the autocorrelation coefficients of the two signals obtained from all the tests before each test to analyze the trend changes of the fitted straight line and calculate the timing stability coefficient of each test.

[0035] When a circuit breaker is operating normally, its movement is primarily affected by environmental fluctuations. Changes in the vibration and current signals are highly correlated with the environment, and this phenomenon is a normal fluctuation in the circuit breaker's detection signals. Therefore, when using vibration and current signals to diagnose mechanical faults in the circuit breaker's operating mechanism, it is necessary to minimize the effects of signal changes caused by environmental fluctuations, thereby reducing the probability of misjudgment of faults due to environmental fluctuations. However, when a circuit breaker experiences a mechanical fault, in addition to the effects of environmental fluctuations, the mechanical fault will have a major impact on the breaker's mechanical movement, weakening the correlation between vibration and current signal fluctuations and environmental changes. At this point, the signal fluctuations and the errors they contain are primarily caused by the fault. To ensure the accuracy and sensitivity of fault detection, it is necessary to retain more signal fluctuations.

[0036] Secondly, the temporal variation characteristics of the signal also have a significant impact on the subsequent signal processing. Under normal circumstances, although there are certain trend fluctuations in the temporal variation of the vibration signal and the current signal, the trend is relatively weak, the overall trend is relatively stable, and the speed of the trend change is slow; secondly, the movement of the circuit breaker is relatively close, that is, the signal data between different detections has relatively strong periodic changes. However, when there is a mechanical fault in the circuit breaker, the temporal variation trend of the vibration signal and the current signal will be more obvious, and the impact of the fault will cause the circuit breaker to deteriorate further, so the trend change speed is faster. At the same time, due to the faster trend and speed of change, the periodicity is also weaker.

[0037] Accordingly, this application is based on Take the circuit breaker test as an example, The vibration sequence and current sequence constitute the first The total vibration sequence and total current sequence detected. The total vibration sequence and total current sequence detected in the first test are taken as input, and the autocorrelation coefficient method is used to obtain the respective autocorrelation coefficient sequences. The largest autocorrelation coefficient of each autocorrelation coefficient sequence is taken as the first The vibration coefficient and current coefficient of the test are measured again.

[0038] Separately The vibration coefficient and current coefficient of the ith detection are used as the ordinate, and the corresponding detection order is used as the abscissa. A straight line fitting is performed and the fitting straight line equation is output, which is recorded as the fitting straight line of the vibration autocorrelation coefficient at the i-th detection.

[0039] The total vibration sequence and total current sequence during the i-th detection are then used as inputs, and STL time series decomposition is used to output the corresponding trend sequence. The autocorrelation coefficient method, straight line fitting, and STL time series decomposition are well-known techniques and will not be described in detail.

[0040] : It is The timing stability coefficient during the second detection, 、 They are The measurement of the time series change of the vibration signal and the current signal during the detection. In this embodiment, , 、 Respectively sequence The slope of the fitting line of the vibration autocorrelation coefficient during the first detection, is the average rate of change of adjacent elements in the trend sequence of the total vibration sequence at the i-th detection; Similarly, the current signal is calculated. , 、 Respectively sequence The slope of the fitting line of the current autocorrelation coefficient during the first detection, is the average change rate of adjacent elements in the trend sequence of the total current sequence at the i-th detection.

[0041] Under normal circumstances, the vibration signal's trend changes relatively slowly and exhibits strong periodicity. This means the corresponding vibration coefficient also changes relatively gently, resulting in a relatively large timing stability coefficient. Conversely, when a circuit breaker experiences an anomaly, the signal's trend changes increasingly rapidly and its periodicity deteriorates, resulting in a smaller timing stability coefficient.

[0042] Step three: based on the environmental disturbance coefficient and the timing stability coefficient, a step size for adaptive filtering of the signal is constructed to perform adaptive filtering on the vibration signal and the current signal; and based on the filtered signal, the circuit breaker fault is monitored.

[0043] Due to the complexity of the working environment of the circuit breaker, it is difficult to perform completely accurate prior statistical analysis, and among various signal processing methods, the adaptive filtering algorithm can achieve good filtering effect in the case of insufficient prior statistical characteristics, so the adaptive filtering is used for signal processing in the application.

[0044] First, the vibration signal and the on-off coil current signal are respectively taken as inputs, the vibration signal and the on-off coil current signal at the first detection are taken as expected signals, the step size for adaptive filtering is obtained by using the following step size formula, the adaptive filtering algorithm is used, and the filtered vibration signal and current signal are output. The adaptive filtering algorithm is a known technology and will not be described in detail.

[0045] : is the step size for adaptive filtering of the signal at the n-th detection, , , is the maximum and minimum step size preset, , is the step size for adaptive filtering of the signal at the n-th detection, , is the normalized environmental disturbance coefficient and timing stability coefficient at the n-th detection, is a preset smoothing factor to prevent the denominator from being zero and control the transition slope, and in the embodiment, the upper quartile value of the sum of the first , respectively take the values 0.1 and 0.001.

[0046] It can be understood that when the circuit breaker is in normal condition, the correlation between the circuit breaker and the environment is relatively strong, and the signal change trend is relatively slow and the periodicity is relatively strong. At this time, when filtering, the main factor affecting the accuracy of the vibration signal and the current signal is the error caused by environmental fluctuations, so a relatively small step size can be used at this time to improve the noise elimination ability and avoid excessive error leading to subsequent misdiagnosis problems. Conversely, when the circuit breaker is more likely to have mechanical faults, the fault is more dominant to the signal fluctuation, so a larger step size should be used at this time to avoid excessive filtering of noise, retain more details, and improve the sensitivity and accuracy of fault identification.

[0047] In the process of monitoring the circuit breaker, the opening and closing movement of the circuit breaker is monitored, vibration signals and current signals collected in the opening and closing movement are filtered according to the step length of the method, and the filtered signals are analyzed to realize the detection of mechanical faults of the circuit breaker operation structure.

[0048] It should be noted that the method of detecting faults by extracting and analyzing the vibration signals and current signals is a known technology in the related field, and will not be described in detail. In different processing methods, the feature extraction and analysis method can include but is not limited to principal component analysis, time-frequency domain analysis, and grey correlation analysis.

[0049] Embodiment 2 Another embodiment of the present application also provides a circuit monitoring device for electrical safety protection, which comprises an acquisition module, a filtering module and a monitoring module. The acquisition module is used to acquire vibration signals, opening and closing coil current signals and environmental parameters of the circuit breaker in each detection during operation. The environmental parameters include environmental temperature and humidity. The filtering module is used to filter and process the vibration signals and current signals by analyzing the data collected by the monitoring module, and the filtering process implements the steps of the circuit monitoring method for electrical safety protection described above. The monitoring module is used to monitor the faults of the circuit breaker based on the filtered signals.

[0050] Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The application is intended to cover any variations, uses or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice in the art to which the application pertains.

[0051] It should be understood that the present application is not limited to the precise construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope thereof.

Claims

1. A circuit breaker monitoring method for electrical safety protection, characterized in that: The method comprises the following steps: Collect vibration signals, opening and closing coil current signals and environmental parameters detected each time the circuit breaker is working; the environmental parameters include ambient temperature and humidity; The cross-correlation analysis method is used to analyze the vibration hysteresis between the vibration signals and current signals of all previous tests and the vibration signals and current signals corresponding to the first test. The environmental disturbance coefficient of each test is calculated by combining the fluctuation characteristics of the vibration and current signals with the correlation between the environmental parameters. The autocorrelation coefficient is used to analyze the autocorrelation coefficients of the vibration signal and the current signal of all the tests before each test; the autocorrelation coefficients of the two signals obtained from all the tests before each test are respectively fitted with a straight line to analyze the trend change of the fitted straight line, and the time series stability coefficient of each test is calculated; The vibration signal and current signal during the first detection are used as the expected signals. The environmental disturbance coefficient and the time series stability coefficient are used to construct the step size for adaptive filtering of the signal, so as to filter the vibration signal and current signal of each subsequent detection. Circuit breaker fault monitoring is performed based on the filtered signals.

2. The circuit breaker monitoring method for electrical safety protection according to claim 1, characterized in that: The method for detecting the vibration signal and the opening and closing coil current signal each time is as follows: collecting the vibration signal when the circuit breaker is working, amplifying the vibration signal using a charge amplifier, and inputting the amplified signal into an oscilloscope; when the vibration signal is greater than a preset trigger value, automatically saving the data 100ms before and after the vibration signal, and using this segment of data as the vibration signal for one detection, and using this time range as the time period for one detection; and using the opening and closing coil current signal within this time period as the opening and closing coil current signal for this detection.

3. The circuit breaker monitoring method for electrical safety protection according to claim 2, characterized in that: The environmental parameters are obtained at the last data collection moment within the detection time period during each detection.

4. The circuit breaker monitoring method for electrical safety protection according to claim 1, wherein: Analyze the vibration hysteresis between the vibration signals and current signals of all previous tests and the vibration signals and current signals corresponding to the first test; and calculate the environmental disturbance coefficient of each test based on the correlation between the fluctuation characteristics of the vibration and current signals and the environmental parameters, including: The vibration signal of each detection is used to form a vibration sequence, and the vibration hysteresis between the vibration sequence of all the detections before each detection and the vibration sequence of the first detection is calculated; The current signal at each detection is used to form a current sequence, and the current hysteresis between the vibration sequence at all detections before each detection and the vibration sequence at the first detection is calculated; and a trend sequence of the current hysteresis sequence is obtained; Calculate the variance of the vibration sequence at each detection to form a vibration fluctuation sequence; Calculate the mean value of the current sequence at each detection to form a current fluctuation sequence; Obtain the temperature data for each test and all previous tests to form a temperature sequence; Obtain the humidity data for each test and all previous tests to form a humidity sequence; Based on the correlation between the first-order difference sequence of the trend sequence, vibration hysteresis, vibration fluctuation sequence and current fluctuation sequence and the temperature sequence and humidity sequence respectively, the environmental disturbance coefficient of each detection is calculated.

5. The circuit breaker monitoring method for electrical safety protection according to claim 4, characterized in that: The vibration hysteresis is the hysteresis corresponding to the maximum value of the cross-correlation coefficient when the cross-correlation analysis method is used between two vibration sequences.

6. The circuit breaker monitoring method for electrical safety protection according to claim 4, characterized in that: Based on the correlation between the first-order difference sequence of the trend sequence, the vibration hysteresis, the vibration fluctuation sequence, and the current fluctuation sequence and the temperature sequence and humidity sequence respectively, the environmental disturbance coefficient of each detection is calculated, including: : It is The environmental disturbance coefficient at the time of the first detection, It is The correlation measure between the temperature series and the vibration lag series at the time of the first detection, 、 It is The correlation measurement between the temperature series, humidity series and vibration fluctuation series at the time of the first detection, It is The mean value of the elements in the first-order difference sequence of the trend sequence of the current hysteresis sequence at the time of the first detection, It is The trend measure of the correlation between the humidity series and the current fluctuation series at each detection time.

7. The circuit breaker monitoring method for electrical safety protection according to claim 4, characterized in that: The autocorrelation coefficient is used to analyze the autocorrelation coefficients of the vibration signal and current signal of all the tests before each test. The autocorrelation coefficients of the two signals obtained from all the tests before each test are fitted with a straight line to analyze the trend change of the fitted line, and the timing stability coefficient of each test is calculated, including: The vibration sequences of each test and all previous tests are combined into a total vibration sequence according to the test order; Calculate the autocorrelation coefficient of the total vibration sequence as the ordinate, take the detection order as the abscissa, perform straight line fitting, and obtain the fitting straight line of the vibration autocorrelation coefficient; The current sequences of each test and all previous tests are combined into a total current sequence according to the test order; Calculate the autocorrelation coefficient of the total current sequence as the ordinate, take the detection order as the abscissa, perform straight line fitting, and obtain the fitting straight line of the current autocorrelation coefficient; The time series stability coefficient of each detection is calculated using the slope change of the fitting line of the vibration and current autocorrelation coefficients and the average change rate of adjacent elements in the trend sequence of the total vibration sequence and the total current sequence.

8. The circuit breaker monitoring method for electrical safety protection according to claim 7, wherein: The time series stability coefficient for each test is calculated using the slope change of the fitting line of the vibration and current autocorrelation coefficients and the average change rate of adjacent elements in the trend sequence of the total vibration sequence and the total current sequence, including: : It is The timing stability coefficient during the second detection, 、 They are The measurement of the time series change of the vibration signal and current signal during the detection; , 、 Respectively sequence The slope of the fitting line of the vibration autocorrelation coefficient during the first detection, is the average rate of change of adjacent elements in the trend sequence of the total vibration sequence at the i-th detection; , 、 Respectively sequence The slope of the fitting line of the current autocorrelation coefficient during the first detection, is the average change rate of adjacent elements in the trend sequence of the total current sequence at the i-th detection.

9. The circuit breaker monitoring method for electrical safety protection according to claim 1, wherein: The formula for constructing the step size of the adaptive filtering of the signal is: : It is The step size of adaptive filtering of the signal during the second detection, 、 are the preset maximum and minimum step sizes, 、 It is The normalized environmental disturbance coefficient and time series stability coefficient during the first detection, It is a preset smoothing factor that prevents the denominator from reaching zero and controls the transition slope.

10. A circuit breaker monitoring device for electrical safety protection, comprising an acquisition module, a filtering module, and a monitoring module; wherein: An acquisition module is used to collect vibration signals, opening and closing coil current signals and environmental parameters detected each time the circuit breaker is working; the environmental parameters include ambient temperature and humidity; A filtering module, configured to filter the vibration signal and the current signal by analyzing the various data collected by the monitoring module, wherein the filtering process is performed to implement the steps of the circuit breaker monitoring method for electrical safety protection according to any one of claims 1 to 9; The monitoring module is used to perform circuit breaker fault monitoring based on the filtered signal.

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