Circuit breaker fault diagnosis system and method

Abstract

The invention discloses a circuit breaker fault diagnosis system and method, and particularly relates to the technical field of circuit breaker diagnosis. According to the invention, through the root-mean-square value, kurtosis and zero-crossing frequency of the time-domain signal and the dominant frequency and high-frequency energy ratio parameters of the frequency domain, and by combining the stroke length, the average displacement speed and the root-mean-square error of the displacement time curve, the mechanical difference evaluation index of the circuit breaker is obtained, and the multi-dimensional evaluation of the mechanical state of the circuit breaker is realized. According to the method, initial similar cases are screened through early warning depth values, parameters are converted into coordinate points in a rectangular plane coordinate system, and the similarity between a current fault and an abnormal case is quantified through a line distance value and an Euclidean distance, so that subjective judgment errors are avoided, and the accuracy of abnormal reason estimation is improved; the problems that in the prior art, existing fault diagnosis mostly depends on single parameter analysis, and the fault of the circuit breaker cannot be rapidly positioned by combining a multi-parameter analysis result and historical data are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breaker diagnosis, and more particularly, to a circuit breaker fault diagnosis system and method. Background Art

[0002] As an important control and protection device in the power system, the normal operation of the circuit breaker is crucial to the stability and safety of the power system.

[0003] At present, there are still the following deficiencies in the fault diagnosis of circuit breakers: On the one hand, existing fault diagnosis mostly relies on single parameter analysis, such as focusing only on a single indicator such as vibration kurtosis or displacement velocity. This makes it difficult to fully cover the multiple failure modes that may occur in circuit breakers, and it is impossible to combine multi-parameter analysis results with historical data to quickly locate circuit breaker faults. On the other hand, existing fault diagnosis lacks effective monitoring methods for the long-term evolution trend of the mechanical state of circuit breakers. It often only focuses on single-point detection of immediate abnormalities, making it difficult to capture abnormal risks that may exist but do not exceed the threshold, and cannot achieve predictive maintenance of circuit breakers.

[0004] Therefore, a circuit breaker fault diagnosis system and method are introduced. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, embodiments of the present invention provide a circuit breaker fault diagnosis system and method.

[0006] To achieve the above object, the present invention provides the following technical solutions: A circuit breaker fault diagnosis system includes the following modules: Benchmark building module: records the mechanical data of the circuit breaker during the initial operation phase and builds a health profile of the circuit breaker; the mechanical data includes vibration data and displacement travel data; Timing analysis module: Sets the evaluation time window of the circuit breaker, which includes a short-term window and a long-term window. Comprehensively evaluates the mechanical data of the circuit breaker within the short-term window to obtain the mechanical abnormality evaluation index of the circuit breaker corresponding to the current short-term window. Case combination module: If the mechanical abnormality assessment index of a circuit breaker within a short-term window is higher than the preset mechanical abnormality threshold index, an early warning signal is triggered. The current circuit breaker's mechanical abnormality assessment index is input into the database for screening and matching of abnormal cases. The abnormal case with the highest credibility value is screened from the matched abnormal cases, and the cause of the abnormality is extracted from it as the estimated cause of the current circuit breaker triggering the early warning signal; Long-term diagnosis module: If the cumulative time during which the circuit breaker fails to trigger an early warning signal reaches the set long-term window duration, the time-dimensional change signal is triggered. A comprehensive evaluation is performed on the mechanical data of the circuit breaker within the long-term window to obtain the mechanical change assessment index corresponding to the circuit breaker within the current long-term window. The trend level of the circuit breaker is then output. The trend level includes the no obvious trend level and the trend maintenance level.

[0007] Specifically, the comprehensive evaluation of the vibration data of the circuit breaker within the short-term window is as follows: Extract the time domain signal from the vibration data of the circuit breaker within the short-term window, intercept the complete vibration process signal from the time domain signal, record it as a discrete sequence x(n) (n=1,2,...,N, N is the number of sampling points), calculate the root mean square value and sheath based on the discrete sequence; For the time domain waveform characteristics, count the number of times the signal crosses the zero level in a short-term window and calculate the frequency, which is recorded as the zero-crossing frequency; convert the time domain signal into the frequency domain to obtain the spectrum amplitude; and record the frequency point with the largest amplitude in the spectrum as the main frequency; By setting the high frequency threshold, the frequencies above the high frequency threshold are divided from the frequency domain and marked as high frequencies. The proportion of high frequency energy to total energy is calculated and recorded as high frequency energy proportion. The root mean square value, sheath degree, zero-crossing frequency, main frequency, and high-frequency energy ratio are evaluated based on the corresponding vibration data of the circuit breaker within a short-term window; the reference root mean square value, reference sheath degree, reference zero-crossing frequency, reference main frequency, and reference high-frequency energy ratio determined during the initial operation phase are extracted from the health record of the circuit breaker; The root mean square value, sheath degree, zero-crossing frequency, main frequency and high-frequency energy ratio evaluated from the vibration data of the circuit breaker within the short-term window are comprehensively analyzed in combination with the corresponding reference root mean square value, reference sheath degree, reference zero-crossing frequency, reference main frequency and reference high-frequency energy ratio to determine the vibration hazard value of the circuit breaker within the short-term window.

[0008] Specifically, the comprehensive evaluation of the displacement travel data of the circuit breaker within the short-term window is as follows: For the displacement travel data of the circuit breaker within the short-term window, the travel length and travel time during the opening and closing process are extracted; the ratio between the travel length and travel time is calculated to obtain the average displacement speed of the circuit breaker; Extract the displacement-time curve during the circuit breaker opening and closing process. Extract the standard opening and closing stroke length, normal displacement average speed, and normal displacement-time curve determined during the initial operation phase from the circuit breaker's health file. Perform time alignment on the current displacement curve and the normal displacement-time curve, and calculate the root mean square error after alignment. A comprehensive analysis is performed on the root mean square error, stroke length, and average displacement speed of the circuit breaker, combined with the corresponding standard opening and closing stroke length, normal displacement average speed, and normal displacement time curve, to determine the circuit breaker's trip value within the short-term window.

[0009] Specifically, the mechanical abnormality assessment index of the current circuit breaker is input into the database to screen and match abnormal cases, specifically as follows: Extract the vibration and operating values ​​of the circuit breaker in the short-term window and conduct comprehensive analysis to obtain the mechanical abnormality assessment index of the circuit breaker in the short-term window; Calculate the difference between the mechanical abnormality assessment index and the mechanical abnormality threshold index, and record it as the warning depth value; For the matched abnormal cases, the warning depth values ​​of each group of abnormal cases are extracted and the difference between them and the warning depth values ​​of the current triggered warning signal is calculated, and the absolute value is taken to obtain the index difference value; the index difference value calculated for each group of abnormal cases is compared with the set difference threshold, and the abnormal cases with index difference values ​​lower than the difference threshold are retained as the initial similar cases.

[0010] Specifically, the abnormal case with the highest credibility value is selected from the matched abnormal cases. The specific credibility value calculation process is: Extract the mechanical anomaly assessment index from the initial similar cases, and analyze and obtain the vibration and line values ​​of the initial similar cases. Use the vibration and line values ​​as the horizontal and vertical coordinates respectively to analyze and obtain the line distance value of each group of initial similar cases. The vibration and line values ​​of the initial similar cases are analyzed separately to obtain the root mean square value, sheath degree, zero-crossing frequency, main frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement speed of the initial similar cases; and the distance value is calculated using Euclidean distance between the root mean square value, sheath degree, zero-crossing frequency, main frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement speed of the current trigger warning signal. A comprehensive analysis of the line distance value and the distance value is performed to obtain the credibility value of each group of initial similar cases; For each group of initial similar cases, the initial similar cases with larger credibility values ​​are extracted as reference cases for triggering the current warning signal, and the abnormal reasons for triggering the warning signal of the reference cases are used as the estimated reasons for the current circuit breaker triggering the warning signal.

[0011] Specifically, the line distance values ​​of each group of initial similar cases are obtained as follows: Construct a plane rectangular coordinate system, draw the coordinate points of each group of initial similar cases corresponding to the horizontal and vertical coordinates in the plane rectangular coordinate system as case points; use the vibration and line values ​​that currently trigger the early warning signal as the horizontal and vertical coordinates, and draw the coordinate points in the plane rectangular coordinate system as signaling points; use the signaling point as the starting point, construct a straight line segment between the signaling point and each group of case points, and obtain the length of the straight line segment as the line distance value of each group of initial similar cases.

[0012] Specifically, the comprehensive evaluation of the vibration data and displacement travel data of the circuit breaker within the long-term window is as follows: After the time-dimensional change signal is triggered, the vibration data and displacement travel data of the circuit breaker within the long-term window are analyzed to obtain the mechanical abnormality assessment index at each set time point within the long-term window; The mechanical abnormality evaluation index of each set time point in the long-term window is extracted, and the standard deviation is calculated to obtain the stabilization value of the circuit breaker in the long-term window; the long-term window is divided into the front time zone and the back time zone according to the midpoint, and the average value of the mechanical abnormality evaluation index of each set time point in the front time zone is calculated and recorded as the front-time mechanical value; the average value of the mechanical abnormality evaluation index of each set time point in the back time zone is calculated and recorded as the back-time mechanical value; the mechanical ratio of the circuit breaker in the long-term window is calculated by taking the back-time mechanical value as the numerator and the front-time mechanical value as the denominator.

[0013] Specifically, the mechanical change assessment index of the circuit breaker corresponding to the current long-term window is obtained as follows: For the post-time mechanical value, the ratio between it and the preset mechanical abnormality threshold index is further calculated, that is, the post-time mechanical value is the numerator and the mechanical abnormality threshold index is the denominator; the warning distance value of the circuit breaker in the long-term window is obtained; A comprehensive analysis is performed on the stabilization value, mechanical ratio and warning distance value of the circuit breaker in the long-term window to obtain the mechanical change assessment index of the circuit breaker corresponding to the current long-term window.

[0014] Specifically, the trend level of the output circuit breaker is: The mechanical change assessment index of the circuit breaker in the current long-term window is matched with the preset index threshold range. If the mechanical change assessment index is within the index threshold range, the trend level of the circuit breaker in the current long-term window is determined to be no obvious trend level; if the mechanical change assessment index is higher than the index threshold range, the trend level of the circuit breaker in the current long-term window is determined to be trend maintenance level.

[0015] A circuit breaker fault diagnosis method, comprising: Archive construction: Extract the vibration data and displacement travel data of the circuit breaker during the initial operation stage and build a health archive of the circuit breaker; Time zone setting: Set the evaluation time window of the circuit breaker, which includes short-term window and long-term window; Abnormal analysis: Comprehensively evaluate the vibration data and displacement travel data of the circuit breaker within the short-term window to obtain the mechanical abnormality assessment index of the circuit breaker corresponding to the current short-term window; Historical integration: If the circuit breaker's mechanical abnormality assessment index within a short-term window is higher than the preset mechanical abnormality threshold index, an early warning signal is triggered and abnormal cases are extracted from the database for similarity analysis. The abnormal case with the highest credibility value is screened out, and the cause of the abnormality is extracted from it as the estimated cause of the current circuit breaker triggering the early warning signal; Long-term tracking: If the cumulative time during which the circuit breaker fails to trigger an early warning signal reaches the set long-term window duration, the time-dimensional change signal is triggered. A comprehensive evaluation is performed on the vibration data and displacement travel data of the circuit breaker within the long-term window to obtain the mechanical change assessment index of the circuit breaker corresponding to the current long-term window, thereby outputting the trend level of the circuit breaker.

[0016] The technical effects and advantages of the present invention are as follows: The present invention obtains the mechanical abnormality assessment index of the circuit breaker by combining the root mean square value, kurtosis, and zero-crossing frequency of the time domain signal, as well as the main frequency and high-frequency energy ratio parameters in the frequency domain, with the stroke length, average displacement velocity, and root mean square error of the displacement time curve. This enables a multi-dimensional assessment of the mechanical state of the circuit breaker. After triggering the early warning signal, the initial similar cases are screened by the early warning depth value, and the parameters are converted into coordinate points in a plane rectangular coordinate system. The similarity between the current fault and the abnormal case is quantified by the line distance value and the Euclidean distance, avoiding subjective judgment errors and improving the accuracy of abnormality cause estimation. This solves the problem in the existing technology that existing fault diagnosis mostly relies on single parameter analysis and cannot combine multi-parameter analysis results with historical data to quickly locate circuit breaker faults. The present invention comprehensively analyzes the three-dimensional parameters of the stabilization value, mechanical ratio, and warning distance value within a long-term window when triggering the time-dimensional change signaling. This captures the progressive degradation of the circuit breaker that does not exceed the threshold. The mechanical change assessment index is matched with the preset threshold, and the trend level is divided into levels. This intuitively displays the evolution of the equipment status and provides data support for predictive maintenance. This solves the problem that the existing technology lacks effective monitoring methods for the long-term evolution trend of the circuit breaker mechanical status and often focuses only on single-point detection of immediate anomalies. The present invention improves the accuracy of the short-term window assessment of the circuit breaker's mechanical state by recording the mechanical data of the initial operation stage as a reference benchmark; The present invention can effectively improve the accuracy, timeliness and maintenance efficiency of circuit breaker fault diagnosis and ensure the stable operation of the power system through multi-dimensional fault feature extraction, precise positioning of historical cases, and quantitative evaluation of long-term trends. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of a circuit breaker fault diagnosis system according to the present invention; Figure 2 The present invention is a flow chart of a circuit breaker fault diagnosis method. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] Example 1 like Figure 1 As shown, a circuit breaker fault diagnosis system module includes a benchmark construction module, a timing analysis module, a case combination module, and a long-term diagnosis module; Benchmark construction module: Utilizes sensors including but not limited to vibration sensors, displacement sensors, travel sensors, and speed sensors. The vibration sensors are installed in the mechanical transmission components, housing, and other locations of the circuit breaker to collect mechanical vibration data during the circuit breaker's opening and closing operations and normal operation; the displacement sensors are used to monitor the displacement changes of components such as contacts and transmission rods; and the travel sensors are used to record the opening and closing strokes of the contacts. Each sensor collects mechanical parameters in real time at a set sampling frequency (e.g., 100Hz-1000Hz), converts the collected analog signals into digital signals, and transmits them via wired or wireless communication after pre-processing such as filtering and noise reduction. Record the vibration data and displacement stroke data collected above, extract the vibration data and displacement stroke data of the circuit breaker during the initial operation stage, and build a health file of the circuit breaker; Based on the recorded vibration and displacement data of the circuit breaker, a mechanical health profile is constructed for each circuit breaker. The health profile also contains basic information about the circuit breaker (model, specifications, installation time, manufacturer, etc.). When constructing the health profile, a statistical analysis is performed on the mechanical data during the initial operation phase (e.g., the first 72 hours). The real-time data, average value, standard deviation, and other statistical quantities of each mechanical data are calculated to determine its normal operating reference value. Time Series Analysis Module: Technicians set the circuit breaker evaluation time window, which includes a short-term window and a long-term window. The short-term window (10-30 minutes) is used to capture sudden abnormalities, while the long-term window (1-30 days) is used to analyze aging trends. A comprehensive evaluation of the circuit breaker's vibration data and displacement travel data within the short-term window is performed to obtain the circuit breaker's mechanical abnormality evaluation index (Ete) within the current short-term window. Specifically: Extract the time domain signal from the vibration data of the circuit breaker within a short-term window. Based on the action sequence, extract the complete vibration process signal from the time domain signal and record it as a discrete sequence x(n) (n=1, 2, ..., N, where N is the number of sampling points). Denoise and enhance the original vibration signal. Use low-pass / high-pass filters to remove noise in specific frequency bands (such as power frequency interference), and median filtering to eliminate impulse noise. Based on discrete sequence, using formula Calculate the RMS value ; Reflects the average energy level of the signal, is sensitive to the intensity of continuous vibration, and reflects the degree of wear of mechanical parts; Based on discrete sequence, using formula Calculate sheath ;in is the mean, is the standard deviation; it measures the "peakedness" of the signal amplitude distribution. Normal vibration signals follow a Gaussian distribution (kurtosis ≈ 3). When an impact fault occurs (such as abnormal contact collision or bearing peeling), the kurtosis value increases significantly. For the time domain waveform characteristics, count the number of times the signal crosses the zero level in the short-term window and calculate the frequency, that is, calculate the ratio of the number of times to the short-term window, and record the calculated frequency as the zero-crossing frequency ; Abnormal zero-crossing frequency may correspond to vibration frequency disorder; The time domain signal is converted into the frequency domain through the fast Fourier transform (FFT) to obtain the spectrum amplitude; the frequency point with the largest amplitude in the spectrum is recorded as the main frequency. ; Preset high frequency band division rules; the frequency band greater than 10kHz can be defined as the high frequency band; divide the high frequency from the frequency domain, calculate the proportion of high frequency band energy to total energy, and record it as the high frequency energy proportion ; The energy in the high-frequency band increases sharply compared to normal operation, which reflects local impact or friction (such as contact wear); Supplementary explanation: Through time domain parameters such as RMS value, kurtosis, and zero-crossing frequency, as well as frequency domain parameters such as main frequency and high-frequency energy ratio, the vibration signal characteristics are captured from different dimensions. For example, the RMS value reflects the intensity of continuous vibration, the kurtosis is sensitive to impact faults, and the main frequency and high-frequency energy ratio reveal abnormal frequency components, forming a three-dimensional portrayal of the mechanical state of the circuit breaker. The RMS value evaluated based on the corresponding vibration data of the circuit breaker within a short-term window , sheath , zero-crossing frequency , main frequency And the proportion of high-frequency energy ; Extract the reference RMS value, reference sheath, reference zero-crossing frequency, reference main frequency and reference high-frequency energy ratio determined in the initial operation stage from the health file of the circuit breaker, and record them as ; The initial operation phase can be divided into various sub-operation time zones according to the duration of the short-term window, and the average values ​​corresponding to the root mean square value, sheath degree, zero-crossing frequency, main frequency and high-frequency energy proportion in each sub-operation time zone are calculated respectively as the reference root mean square value, reference sheath degree, reference zero-crossing frequency, reference main frequency and reference high-frequency energy proportion; Supplementary explanation: reference values ​​(such as RMS value, kurtosis, etc.) of the initial operation phase were extracted from the health records and calculated by averaging the sub-operation time periods to eliminate the influence of equipment factory differences and installation errors; Using the formula Perform comprehensive calculations to determine the vibration damage value of the circuit breaker within the short-term window ;in RMS values , sheath , zero-crossing frequency , main frequency And the proportion of high-frequency energy The corresponding weight coefficient; In addition, the vibration value quantifies the overall abnormal state of the circuit breaker's mechanical components by integrating the deviations of time-domain and frequency-domain parameters. It reflects the fault superposition effect more comprehensively than a single parameter. The larger the vibration value, the more the parameter deviates from the reference value, and the higher the risk of mechanical failure. For the displacement travel data of the circuit breaker within the short-term window, the travel length and travel time during the opening and closing process are extracted; Calculate the ratio between the stroke length and the stroke time to obtain the average displacement speed of the circuit breaker; If the average displacement velocity deviates significantly from the normal condition, the corresponding mechanical condition is poor. The reasons include: Possible reasons for low average speed Mechanical jamming or increased resistance: For example, poor lubrication of the transmission rod, aging of the contact spring, deformation of the mechanism components, etc., which will lead to prolonged action time, and the total displacement may be reduced due to inadequate travel, ultimately reducing the average speed; Insufficient power source: If the energy output of the operating mechanism (such as spring operation or hydraulic operation) decreases, the components cannot be driven to reach the normal speed. For example, the spring of the spring operating mechanism is fatigued, resulting in insufficient energy when closing the switch, resulting in a low closing speed; Possible reasons for high average speed Reduced mechanical resistance or loose components: For example, if the clearance between transmission components is too large or the fixing bolts are loose, the frictional resistance will be reduced during operation and the speed will increase abnormally; Extract the displacement time curve during the circuit breaker opening and closing process, and extract the standard opening and closing stroke length, normal displacement average speed, and normal displacement time curve determined during the initial operation phase from the circuit breaker health file; During the initial operation phase of the circuit breaker, 20 opening and closing displacement data can be collected, and the average length of the stroke in each opening and closing process can be calculated as the standard opening and closing stroke length; the average speed of the displacement in each opening and closing process can be used as the normal average speed of displacement; the fitting curve of the displacement time curve in each opening and closing process can be obtained by fitting the 20 displacement curves at the same time point. Calculate the mean and build the curve based on the mean of each group; Perform time alignment on the current displacement curve and the normal displacement time curve; take the action triggering moment as the benchmark; calculate the root mean square error after alignment , the formula is expressed as ;c is the total number of time points in the opening and closing process, and i is the time point number; An increase indicates that the motion trajectory deviates from the normal state, which may be caused by wear of mechanical parts or loose connections; Using the formula Perform comprehensive calculations to determine the circuit breaker's operating risk within a short-term window ; denote the stroke length and average displacement velocity respectively; Respectively represent the standard opening and closing stroke length and the normal displacement average speed; are the weight coefficients corresponding to the root mean square error, stroke length, and average displacement velocity; Supplementary explanation: By combining core parameters such as stroke length, average displacement speed, and root mean square error of the displacement time curve, an evaluation system is constructed from three dimensions: "whether the stroke length deviates", "whether the movement speed is normal", and "whether the motion trajectory deviates", to avoid the one-sidedness of single parameter analysis; Extract the vibration damage value of the circuit breaker within the short-term window and the value of the row , and substitute into the formula Perform comprehensive calculations to obtain the circuit breaker's mechanical abnormality evaluation index Ete within the short-term window; Vibration value and the value of the line The corresponding weight coefficient; It is supplemented that the calculated mechanical abnormality evaluation index Ete can avoid one-sidedness and cover multiple failure modes; A single parameter (such as only looking at vibration kurtosis or displacement velocity) may lead to misjudgment due to fault superposition or parameter coupling. For example, contact wear may simultaneously cause a surge in high-frequency vibration energy (increased vibration disturbance value) and insufficient displacement travel (increased displacement disturbance value). Mechanical jamming can lead to a decrease in displacement velocity (abnormal displacement disturbance value) accompanied by an increase in vibration intensity (abnormal vibration disturbance value). A comprehensive assessment can eliminate interference from a single factor. Case combination module: If the mechanical abnormality evaluation index (Ete) of a circuit breaker within a short-term window exceeds the preset mechanical abnormality threshold index, an early warning signal is triggered and circuit breaker abnormality cases that match the basic information of the current circuit breaker are extracted from the database for similarity analysis. Each group of circuit breaker abnormality cases includes the time of occurrence, abnormality cause, and handling personnel. Based on the similarity analysis results, the abnormal case with the highest credibility value is screened from the matched circuit breaker abnormality cases, and the abnormal cause is extracted from it as the estimated reason for the current circuit breaker triggering the early warning signal; Specifically: After the early warning signal is triggered, the difference between the mechanical abnormality evaluation index Ete and the mechanical abnormality threshold index is calculated and recorded as the early warning depth value; For matched abnormal cases, the warning depth value of each group of abnormal cases is extracted and the warning depth value of the current triggering warning signal is respectively calculated, and the absolute value is taken to obtain the index difference value; the index difference value calculated for each group of abnormal cases is compared with the set difference threshold, and the abnormal cases with index difference values ​​lower than the difference threshold are retained as the initial similar cases; As a supplementary note, setting a difference threshold (e.g., 0.5) and retaining cases with index difference values ​​below this threshold can eliminate historical cases with significantly different warning levels.

[0020] For example, if the warning severity value of a historical case is 2 and the current value is 4.8, the index difference value is 2.8, which is higher than the threshold, and is filtered out. Only cases with similar warning severity (for example, index difference value ≤ 0.5) are retained. This allows the screening results to focus more on "faults of the same level" and improves the reliability of subsequent cause estimation. Extract the mechanical anomaly assessment index from the initial similar cases, and parse to obtain the vibration and behavior values ​​of the initial similar cases, with the vibration and behavior values ​​as the horizontal and vertical coordinates respectively; Construct a plane rectangular coordinate system, and draw the coordinate points of each group of initial similar cases whose horizontal and vertical coordinates correspond to the plane rectangular coordinate system as case points; The vibration value that triggers the warning signal and the value of the line As the horizontal and vertical coordinates, and plot the coordinate points in the plane rectangular coordinate system as signaling points; Taking the signaling point as the starting point, construct a straight line segment between the signaling point and each group of case points, and obtain the length of the straight line segment as the line distance value of each group of initial similar cases ; Supplementary explanation: Using the vibration value (vibration characteristics) and the travel value (travel characteristics) as two-dimensional coordinates to form a "vibration-travel" dual-parameter fault mapping system can more comprehensively characterize the multi-dimensional characteristics of mechanical faults (such as the correlation between vibration abnormalities and travel deviations) compared to single parameters (such as using only the vibration value or travel value). The historical cases and current signaling points are converted into coordinate points using a plane rectangular coordinate system, which intuitively displays the parameter distribution patterns of different fault types, facilitating the rapid identification of similar fault modes. The line length (distance value) between the signaling point and the case point directly reflects the degree of parameter deviation between the current fault and the historical case. The smaller the distance value, the closer the current vibration and line values ​​are to the historical case, and the higher the similarity of the fault cause. The vibration and travel values ​​of the initial similar cases are analyzed separately to obtain the root mean square value, sheath, zero crossing frequency, main frequency, high frequency energy ratio, root mean square error, stroke length and average displacement speed of the initial similar cases; and compared with the root mean square value of the current trigger warning signal , sheath , zero-crossing frequency , main frequency , high-frequency energy ratio , root mean square error , stroke length and the average displacement velocity The distance value is calculated using Euclidean distance Calculation of Based on the root mean square value, sheath degree, zero-crossing frequency, main frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement speed of the current trigger warning signal, an 8-dimensional parameter vector P = (m1, m2, ..., m8) is constructed; the 8-dimensional parameter vector H = (w1, w2, ..., w8) of the initial similar case is constructed. The formula is expressed as ; s is the number of each parameter in the 8-dimensional parameter vector; Using the formula Calculate the credibility value Lt of each group of initial similar cases; Line distance values and distance values The corresponding weight coefficient; For each group of initial similar cases, the initial similar cases with larger credibility values ​​Lt are extracted as reference cases for triggering the current warning signal, and the abnormal reasons for triggering the warning signal of the reference cases are used as the estimated reasons for triggering the warning signal of the current circuit breaker; In addition, the credibility value calculation integrates the line distance value (two-dimensional coordinate distance) of the "vibration-stroke" dual parameter and the Euclidean distance of the 8-dimensional parameter vector (including detailed features such as root mean square value, sheath, and zero-crossing frequency). It combines the macro characteristics of mechanical failures (such as the correlation between vibration and stroke) with micro characteristics (such as the proportion of high-frequency energy and displacement velocity), avoiding the one-sidedness of single parameter analysis. The smaller the line distance and Euclidean distance values ​​are, the closer the current fault parameters are to the historical cases, and the larger the credibility value Lt is. Through quantitative calculation, the "similarity" is converted into comparable values, avoiding errors in subjective judgment. Long-term diagnosis module: If the cumulative time without triggering the warning signal reaches the set long-term window, the time-dimensional change signal is triggered. The vibration data and displacement travel data of the circuit breaker within the long-term window are comprehensively evaluated to obtain the mechanical change assessment index of the circuit breaker corresponding to the current long-term window, and the trend level of the circuit breaker is output. The trend level includes no obvious trend level and trend maintenance level. To supplement, if the time dimension change signal is triggered, it means that the circuit breaker has not had any mechanical abnormality for a long time. However, for the long-term stable operation of the circuit breaker, it is necessary to capture the slight changes in the mechanical parameters to determine whether there is a trend of mechanical abnormality. Specifically: After the time-dimensional change signal is triggered, the vibration data and displacement travel data of the circuit breaker within the long-term window are analyzed; each set time point is set according to the time length within the long-term window; Extract the mechanical abnormality evaluation index Ete at each set time point within the long-term window and calculate the standard deviation to obtain the stabilization value of the circuit breaker within the long-term window; measure the degree of data dispersion and reflect the trend stability. If the stabilization value is large, it means that the mechanical state stability of the circuit breaker within the long-term window is poor; The long-term window is divided into the front time zone and the back time zone according to the midpoint. The average value of the mechanical abnormality evaluation index Ete at each set time point in the front time zone is calculated and recorded as the front time mechanical value; the average value of the mechanical abnormality evaluation index Ete at each set time point in the back time zone is calculated and recorded as the back time mechanical value; The mechanical ratio of the circuit breaker in the long-term window is obtained by calculating the ratio of the post-mechanical value to the numerator and the pre-mechanical value to the denominator. Supplementary explanation: the value of mechanical ratio reflects: Mechanical ratio is greater than 1: The average Ete in the later time zone is higher than that in the earlier time zone, indicating an upward trend in the mechanical condition assessment index. Since Ete is generally positively correlated with the degree of mechanical abnormality (such as abnormal vibration and travel deviation), this trend may reflect the gradual deterioration of the circuit breaker's mechanical components (such as increased wear and loose components). Although no warning signal has been triggered, there is a potential failure risk. The mechanical ratio is close to 1: There was no significant change in the average Ete values ​​between the previous and next time zones, indicating that the mechanical state was relatively stable; Mechanical ratio <1: The average Ete in the later time zone is lower than that in the earlier time zone, indicating that the mechanical status tends to improve (e.g., disappearance of accidental interference, self-healing of minor abnormalities, etc.); The mechanical ratio compares the mechanical condition assessment index of the previous and next time periods within a long-term window, converting "parameter changes in the time dimension" into a quantifiable trend indicator. Its essence is to capture the gradual evolution of the mechanical condition and provide data support for predictive maintenance of circuit breakers. The ratio of the post-time mechanical value to the preset mechanical abnormality threshold index is further calculated, i.e., the post-time mechanical value is the numerator and the mechanical abnormality threshold index is the denominator; the warning distance value of the circuit breaker within the long-term window is obtained; the closer the warning distance value is to 1, the faster the circuit breaker is approaching the triggering of the early warning signal; Extract the stabilization value, mechanical ratio value and warning distance value of the circuit breaker in the long-term window and mark them as ; Using the formula Comprehensively calculate the stabilization value, mechanical ratio and warning distance value of the circuit breaker in the long-term window to obtain the mechanical change evaluation index Kq of the circuit breaker corresponding to the current long-term window; are the weight coefficients corresponding to the stabilization value, mechanical ratio value and warning distance value respectively; Additional explanation: Breaking through the limitations of single-point detection: Traditional early warnings focus only on immediate anomalies (such as Ete exceeding a threshold), while Kq analyzes long-term data in three dimensions: stability (stable value), trend direction (mechanical ratio), and threshold distance (warning distance). It can capture potential risks that have not exceeded the threshold but are continuously worsening (such as progressive bearing wear and spring elasticity degradation). Match the mechanical change evaluation index Kq of the circuit breaker in the current long-term window with the preset index threshold range. If the mechanical change evaluation index Kq is within the index threshold range, the trend level of the circuit breaker in the current long-term window is determined to be no obvious trend level; If the mechanical change assessment index Kq is higher than the index threshold range, the trend level of the circuit breaker in the current long-term window is determined to be the trend maintenance level; Send the location and trend maintenance level of the circuit breaker to the maintenance personnel, reminding them to go to the location of the circuit breaker for advance maintenance; Supplementary explanation: By matching the mechanical change assessment index with the preset threshold, the "no obvious trend level" and "trend maintenance level" are divided to achieve differentiated maintenance strategies: For equipment with “no obvious trend”, extend the monitoring cycle to reduce unnecessary maintenance costs; For "trend maintenance" equipment, the system proactively pushes location information and maintenance levels to guide maintenance personnel to perform precise operations, avoid blind inspections, and improve maintenance efficiency. Example

[0021] See also Figure 2 As shown, based on the circuit breaker fault diagnosis system provided in Example 1 of this application, Example 2 of this application proposes a circuit breaker fault diagnosis method. Example 2 is only a preferred embodiment of Example 1, and the implementation of Example 2 will not affect the independent implementation of Example 1.

[0022] Specifically, the circuit breaker fault diagnosis method provided in Example 2 of the present application is different in that it includes: Archive construction: Extract the vibration data and displacement travel data of the circuit breaker during the initial operation stage and build a health archive of the circuit breaker; Time zone setting: Set the evaluation time window of the circuit breaker, which includes short-term window and long-term window; Abnormal analysis: Comprehensively evaluate the vibration data and displacement travel data of the circuit breaker within the short-term window to obtain the mechanical abnormality assessment index of the circuit breaker corresponding to the current short-term window; Historical integration: If the circuit breaker's mechanical abnormality evaluation index (Ete) within a short-term window is higher than the preset mechanical abnormality threshold index, an early warning signal is triggered and abnormal cases are extracted from the database for similarity analysis. The abnormal cases with the highest credibility are screened out, and the cause of the abnormality is extracted from them as the estimated cause of the current circuit breaker triggering the early warning signal; Long-term tracking: If the cumulative time without triggering the warning signal reaches the set long-term window, the time-dimensional change signal is triggered. The vibration data and displacement travel data of the circuit breaker within the long-term window are comprehensively evaluated to obtain the mechanical change assessment index of the circuit breaker within the current long-term window, and the trend level of the circuit breaker is output accordingly. The above formulas are all dimensionless and calculated numerically. Specific dimension removal can be achieved by various means such as standardization, which will not be elaborated here. The formula is a formula obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0023] The above embodiments can be implemented in whole or in part via software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product comprises one or more computer instructions or computer programs. When loaded or executed on a computer, the processes or functions described in the embodiments of this application are fully or partially performed. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server or data center that contains a collection of one or more available media. The available medium can be magnetic media (e.g., floppy disks, ATA hard drives, magnetic tapes), optical media (e.g., DVDs), or semiconductor media. The semiconductor media can be a solid-state ATA hard drive.

[0024] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0025] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0026] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0027] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, and may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment as needed.

[0028] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0029] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile ATA hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, and other media that can store program code.

[0030] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A circuit breaker fault diagnosis system, characterized in that: Includes the following modules: Benchmark building module: records the mechanical data of the circuit breaker during the initial operation phase and builds a health profile of the circuit breaker; the mechanical data includes vibration data and displacement travel data; Timing analysis module: Sets the evaluation time window of the circuit breaker, which includes a short-term window and a long-term window. Comprehensively evaluates the mechanical data of the circuit breaker within the short-term window to obtain the mechanical abnormality evaluation index of the circuit breaker corresponding to the current short-term window. Case combination module: If the mechanical abnormality assessment index of a circuit breaker within a short-term window is higher than the preset mechanical abnormality threshold index, an early warning signal is triggered. The current circuit breaker's mechanical abnormality assessment index is input into the database for screening and matching of abnormal cases. The abnormal case with the highest credibility value is screened from the matched abnormal cases, and the cause of the abnormality is extracted from it as the estimated cause of the current circuit breaker triggering the early warning signal; Long-term diagnosis module: If the cumulative time that the circuit breaker fails to trigger the warning signal reaches the set long-term window duration, the time-dimensional change signal is triggered. A comprehensive evaluation is performed on the mechanical data of the circuit breaker within the long-term window to obtain the mechanical change assessment index of the circuit breaker corresponding to the current long-term window, and the trend level of the circuit breaker is output accordingly. The trend levels include no obvious trend level and trend maintenance level.

2. A circuit breaker fault diagnosis system according to claim 1, characterized in that: The comprehensive evaluation of the vibration data of the circuit breaker within the short-term window is as follows: Extract the time domain signal from the vibration data of the circuit breaker within the short-term window, intercept the complete vibration process signal from the time domain signal, record it as a discrete sequence x(n) (n=1,2,...,N, N is the number of sampling points), calculate the root mean square value and sheath based on the discrete sequence; For the time domain waveform characteristics, count the number of times the signal crosses the zero level in a short-term window and calculate the frequency, which is recorded as the zero-crossing frequency; convert the time domain signal into the frequency domain to obtain the spectrum amplitude; and record the frequency point with the largest amplitude in the spectrum as the main frequency; By setting the high frequency threshold, the frequencies above the high frequency threshold are divided from the frequency domain and marked as high frequencies. The proportion of high frequency energy to total energy is calculated and recorded as high frequency energy proportion. The RMS value, sheath, zero-crossing frequency, main frequency, and high-frequency energy ratio evaluated based on the corresponding vibration data of the circuit breaker within a short-term window; Extracting the reference root mean square value, reference sheath degree, reference zero-crossing frequency, reference main frequency, and reference high-frequency energy ratio determined during the initial operation phase from the health file of the circuit breaker; The root mean square value, sheath degree, zero-crossing frequency, main frequency and high-frequency energy ratio evaluated from the vibration data of the circuit breaker within the short-term window are comprehensively analyzed in combination with the corresponding reference root mean square value, reference sheath degree, reference zero-crossing frequency, reference main frequency and reference high-frequency energy ratio to determine the vibration hazard value of the circuit breaker within the short-term window.

3. A circuit breaker fault diagnosis system according to claim 2, characterized in that: The comprehensive evaluation of the displacement travel data of the circuit breaker within the short-term window is specifically as follows: For the displacement travel data of the circuit breaker within the short-term window, the travel length and travel time during the opening and closing process are extracted; the ratio between the travel length and travel time is calculated to obtain the average displacement speed of the circuit breaker; Extract the displacement-time curve during the circuit breaker opening and closing process. Extract the standard opening and closing stroke length, normal displacement average speed, and normal displacement-time curve determined during the initial operation phase from the circuit breaker's health file. Perform time alignment on the current displacement curve and the normal displacement-time curve, and calculate the root mean square error after alignment. A comprehensive analysis is performed on the root mean square error, stroke length, and average displacement speed of the circuit breaker, combined with the corresponding standard opening and closing stroke length, normal displacement average speed, and normal displacement time curve, to determine the circuit breaker's trip value within the short-term window.

4. A circuit breaker fault diagnosis system according to claim 3, characterized in that: The mechanical abnormality assessment index of the current circuit breaker is input into the database to screen and match abnormal cases, specifically: Extract the vibration and operating values ​​of the circuit breaker in the short-term window and conduct comprehensive analysis to obtain the mechanical abnormality assessment index of the circuit breaker in the short-term window; Calculate the difference between the mechanical abnormality assessment index and the mechanical abnormality threshold index, and record it as the warning depth value; For the matched abnormal cases, the warning depth values ​​of each group of abnormal cases are extracted and the difference between them and the warning depth values ​​of the current triggered warning signal is calculated, and the absolute value is taken to obtain the index difference value; the index difference value calculated for each group of abnormal cases is compared with the set difference threshold, and the abnormal cases with index difference values ​​lower than the difference threshold are retained as the initial similar cases.

5. A circuit breaker fault diagnosis system according to claim 4, characterized in that: The abnormal case with the highest credibility value is selected from the matched abnormal cases. The specific credibility value calculation process is as follows: Extract the mechanical anomaly assessment index from the initial similar cases, and analyze and obtain the vibration and line values ​​of the initial similar cases. Use the vibration and line values ​​as the horizontal and vertical coordinates respectively to analyze and obtain the line distance value of each group of initial similar cases. The vibration and travel values ​​of the initial similar cases are analyzed separately to obtain the root mean square value, sheath degree, zero-crossing frequency, main frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement speed of the initial similar cases; The distance value is calculated using the Euclidean distance between the root mean square value, sheath degree, zero-crossing frequency, main frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement speed of the current trigger warning signal; the line distance value and distance value are comprehensively analyzed to obtain the credibility value of each group of initial similar cases; For each group of initial similar cases, the initial similar cases with larger credibility values ​​are extracted as reference cases for triggering the current warning signal, and the abnormal reasons for triggering the warning signal of the reference cases are used as the estimated reasons for the current circuit breaker triggering the warning signal.

6. A circuit breaker fault diagnosis system according to claim 5, characterized in that: The line distance values ​​of each group of initial similar cases are obtained as follows: Construct a plane rectangular coordinate system, plot the coordinate points of each group of initial similar cases corresponding to the horizontal and vertical coordinates in the plane rectangular coordinate system as case points; use the vibration and line values ​​that currently trigger the early warning signal as the horizontal and vertical coordinates, and plot the coordinate points in the plane rectangular coordinate system as signaling points; Taking the signaling point as the starting point, a straight line segment is constructed between the signaling point and each group of case points, and the length of the straight line segment is obtained as the line distance value of each group of initial similar cases.

7. A circuit breaker fault diagnosis system according to claim 6, characterized in that: The comprehensive evaluation of the vibration data and displacement travel data of the circuit breaker within the long-term window is as follows: After the time-dimensional change signal is triggered, the vibration data and displacement travel data of the circuit breaker within the long-term window are analyzed to obtain the mechanical abnormality assessment index at each set time point within the long-term window; The mechanical abnormality evaluation index of each set time point in the long-term window is extracted, and the standard deviation is calculated to obtain the stabilization value of the circuit breaker in the long-term window; the long-term window is divided into the front time zone and the back time zone according to the midpoint, and the average value of the mechanical abnormality evaluation index of each set time point in the front time zone is calculated and recorded as the front-time mechanical value; the average value of the mechanical abnormality evaluation index of each set time point in the back time zone is calculated and recorded as the back-time mechanical value; the mechanical ratio of the circuit breaker in the long-term window is calculated by taking the back-time mechanical value as the numerator and the front-time mechanical value as the denominator.

8. A circuit breaker fault diagnosis system according to claim 7, characterized in that: The mechanical change assessment index of the circuit breaker corresponding to the current long-term window is obtained as follows: For the post-time mechanical value, the ratio between it and the preset mechanical abnormality threshold index is further calculated, that is, the post-time mechanical value is the numerator and the mechanical abnormality threshold index is the denominator; the warning distance value of the circuit breaker in the long-term window is obtained; A comprehensive analysis is performed on the stabilization value, mechanical ratio and warning distance value of the circuit breaker in the long-term window to obtain the mechanical change assessment index of the circuit breaker corresponding to the current long-term window.

9. A circuit breaker fault diagnosis system according to claim 8, characterized in that: The trend level of the output circuit breaker is specifically: The mechanical change assessment index of the circuit breaker in the current long-term window is matched with the preset index threshold range. If the mechanical change assessment index is within the index threshold range, the trend level of the circuit breaker in the current long-term window is determined to be no obvious trend level; if the mechanical change assessment index is higher than the index threshold range, the trend level of the circuit breaker in the current long-term window is determined to be trend maintenance level.

10. A circuit breaker fault diagnosis method, applied to a circuit breaker fault diagnosis system according to any one of claims 1 to 9, characterized in that: include: Archive construction: Extract the vibration data and displacement travel data of the circuit breaker during the initial operation stage and build a health archive of the circuit breaker; Time zone setting: Set the evaluation time window of the circuit breaker, which includes short-term window and long-term window; Abnormal analysis: Comprehensively evaluate the vibration data and displacement travel data of the circuit breaker within the short-term window to obtain the mechanical abnormality assessment index of the circuit breaker corresponding to the current short-term window; Historical integration: If the circuit breaker's mechanical abnormality assessment index within a short-term window is higher than the preset mechanical abnormality threshold index, an early warning signal is triggered and abnormal cases are extracted from the database for similarity analysis. The abnormal case with the highest credibility value is screened out, and the cause of the abnormality is extracted from it as the estimated cause of the current circuit breaker triggering the early warning signal; Long-term tracking: If the cumulative time during which the circuit breaker fails to trigger an early warning signal reaches the set long-term window duration, the time-dimensional change signal is triggered. A comprehensive evaluation is performed on the vibration data and displacement travel data of the circuit breaker within the long-term window to obtain the mechanical change assessment index of the circuit breaker corresponding to the current long-term window, thereby outputting the trend level of the circuit breaker.

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