A circuit breaker fault diagnosis system and method

Abstract

This invention discloses a circuit breaker fault diagnosis system and method, specifically relating to the field of circuit breaker diagnosis technology. The invention obtains a mechanical anomaly assessment index for the circuit breaker by using the root mean square value, kurtosis, and zero-crossing frequency of the time-domain signal, as well as the dominant frequency and high-frequency energy ratio parameters in the frequency domain, combined with the root mean square error of the travel length, average displacement velocity, and displacement-time curve. This achieves a multi-dimensional assessment of the circuit breaker's mechanical state. After triggering an early warning signal, initial similar cases are filtered based on the early warning depth value. The parameters are transformed into coordinate points in a Cartesian coordinate system. The similarity between the current fault and the anomaly case is quantified using the line distance value and Euclidean distance, avoiding subjective judgment errors and improving the accuracy of anomaly cause prediction. This solves the problem that existing fault diagnosis technologies often rely on single-parameter analysis and cannot combine multi-parameter analysis results with historical data for rapid fault location of circuit breakers.

Description

Technical Field

[0001] This invention relates to the field of circuit breaker diagnostic technology, and more specifically, to a circuit breaker fault diagnosis system and method. Background Technology

[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] Currently, there are still the following shortcomings in the fault diagnosis of circuit breakers:

[0004] On the one hand, existing fault diagnosis relies heavily on single-parameter analysis, such as focusing only on single indicators like vibration kurtosis or displacement velocity. This makes it difficult to fully cover the multiple fault modes that circuit breakers may experience and to combine multi-parameter analysis results with historical data to quickly locate faults in circuit breakers.

[0005] On the other hand, existing fault diagnosis methods lack effective means to monitor the long-term evolution trend of the mechanical condition of circuit breakers. They often only focus on single-point detection of immediate anomalies, making it difficult to capture abnormal risks that may exist even if they have not exceeded the threshold, and thus failing to achieve predictive maintenance of circuit breakers.

[0006] Therefore, a circuit breaker fault diagnosis system and method are proposed. Summary of the Invention

[0007] To overcome the above-mentioned deficiencies of the prior art, embodiments of the present invention provide a circuit breaker fault diagnosis system and method.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A circuit breaker fault diagnosis system includes the following modules:

[0010] Benchmark building module: Records the mechanical data of the circuit breaker during the initial operation phase and builds the circuit breaker's health profile; the mechanical data includes vibration data and displacement travel data;

[0011] Time sequence analysis module: Set the evaluation time window for the circuit breaker, which includes a short-term window and a long-term window. Perform a comprehensive evaluation of the mechanical data of the circuit breaker within the short-term window to obtain the mechanical anomaly evaluation index of the circuit breaker corresponding to the current short-term window.

[0012] Case combination module: If the mechanical anomaly assessment index of the circuit breaker is higher than the preset mechanical anomaly threshold index within a short window, an early warning signal is triggered. The current mechanical anomaly assessment index of the circuit breaker is input into the database for screening and matching of abnormal cases. The abnormal case with the highest confidence value is selected from the matched abnormal cases, and the abnormal cause is extracted as the estimated cause of the current circuit breaker triggering the early warning signal.

[0013] Long-term diagnostic module: If the cumulative duration for which the circuit breaker has not triggered a warning signal reaches the set long-term window duration, a time-dimensional change signal is triggered. The mechanical data of the circuit breaker within the long-term window is comprehensively evaluated to obtain the mechanical change evaluation index of the circuit breaker within the current long-term window, thereby outputting the trend level of the circuit breaker; the trend level includes no obvious trend level and trend maintenance level.

[0014] Specifically, the comprehensive evaluation of the vibration data of the circuit breaker within the short-term window includes:

[0015] For the vibration data of the circuit breaker within a short window, the time domain signal is extracted, and the complete vibration process signal is extracted from the time domain signal and denoted as the discrete sequence x(n) (n=1,2,...,N,N is the number of sampling points). Based on the discrete sequence, the root mean square value and sheath strength are calculated.

[0016] For time-domain waveform characteristics, count the number of times the signal crosses zero level within a short window and calculate the frequency, then record the calculated frequency as the zero-crossing frequency; convert the time-domain signal to the frequency domain to obtain the spectral amplitude; and record the frequency point with the largest amplitude in the spectrum as the main frequency.

[0017] By setting a high-frequency threshold, 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 the high-frequency energy percentage.

[0018] Based on the root mean square value, sheath length, zero-crossing frequency, dominant frequency, and high-frequency energy ratio of the circuit breaker corresponding vibration data within the short-term window, the reference root mean square value, reference sheath length, reference zero-crossing frequency, reference dominant frequency, and reference high-frequency energy ratio determined during the initial operation phase are extracted from the circuit breaker's health record.

[0019] The root mean square value, sheath strength, zero-crossing frequency, dominant frequency, and high-frequency energy ratio of the circuit breaker corresponding vibration data within the short-term window are evaluated and then comprehensively analyzed in conjunction with the corresponding reference root mean square value, reference sheath strength, reference zero-crossing frequency, reference dominant frequency, and reference high-frequency energy ratio to determine the vibration risk value of the circuit breaker within the short-term window.

[0020] Specifically, the comprehensive evaluation of the circuit breaker's displacement travel data within the short-term window includes:

[0021] For the displacement travel data of the circuit breaker within a short window, the travel length and travel time during the opening and closing process are extracted; the ratio of the travel length and travel time is calculated to obtain the average displacement speed of the circuit breaker.

[0022] Extract the displacement-time curve during the circuit breaker's opening and closing process. Extract the standard opening and closing stroke length, average normal displacement speed, and normal displacement-time curve determined during the initial operation phase from the circuit breaker's health record. Perform time alignment between the current displacement curve and the normal displacement-time curve, and calculate the root mean square error after alignment.

[0023] The root mean square error, stroke length, and average displacement speed of the circuit breaker are comprehensively analyzed in conjunction with the corresponding standard opening and closing stroke length, normal average displacement speed, and normal displacement time curve to determine the hazard value of the circuit breaker within a short-term window.

[0024] Specifically, the step of inputting the mechanical anomaly assessment index of the current circuit breaker into the database for screening and matching abnormal cases involves:

[0025] The vibration hazard value and the traffic hazard value of the circuit breaker within the short-term window are extracted and comprehensively analyzed to obtain the mechanical hazard assessment index of the circuit breaker within the short-term window.

[0026] The difference between the mechanical abnormality assessment index and the mechanical abnormality threshold index is calculated and recorded as the warning depth value;

[0027] For matched abnormal cases, the difference between the warning depth value of each group of abnormal cases and the warning depth value of the current triggering warning signal is calculated, and the absolute value is taken to obtain the exponential difference value. The exponential difference value calculated for each group of abnormal cases is compared with the set difference threshold, and abnormal cases with exponential difference values ​​lower than the difference threshold are retained as initial similar cases.

[0028] Specifically, the process of selecting the anomaly case with the highest confidence value from the matched anomaly cases involves the following steps:

[0029] The mechanical difference assessment index is extracted from the initial similar cases, and the vibration and lateral hazard values ​​of the initial similar cases are obtained by analysis. The vibration and lateral hazard values ​​are used as the horizontal and vertical axes, respectively, to analyze and obtain the line distance values ​​of each group of initial similar cases.

[0030] The vibration and motion hazard values ​​of the initial similar cases are analyzed to obtain the root mean square value, sheath strength, zero-crossing frequency, dominant frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement velocity of the initial similar cases. The distance between these values ​​and the current trigger warning signal is calculated using Euclidean distance. A comprehensive analysis of the line spacing and distance values ​​is performed to obtain the confidence value of each group of initial similar cases.

[0031] For each group of initial similar cases, the initial similar cases with higher confidence values ​​are extracted as reference cases for triggering the current warning signaling, and the abnormal reasons for triggering the warning signaling in the reference cases are used as the estimated reasons for triggering the current circuit breaker warning signaling.

[0032] Specifically, the line spacing values ​​for each group of initial similar cases are obtained as follows:

[0033] Construct a Cartesian coordinate system and plot the coordinates of each initial similar case in the Cartesian coordinate system as case points; use the vibration and motion values ​​of the current triggering warning signal as the x and y coordinates and plot them in the Cartesian coordinate system as signal points; use the signal points as the starting points and construct straight line segments between the signal points and each group of case points, and obtain the length of the straight line segments as the line distance value of each group of initial similar cases.

[0034] Specifically, the comprehensive evaluation of the vibration data and displacement travel data of the circuit breaker within the long-term window includes:

[0035] After triggering the time-dimensional change signaling, the vibration data and displacement stroke data of the circuit breaker within the long-term window are analyzed to obtain the mechanical anomaly evaluation index at each set time point within the long-term window;

[0036] Extract the mechanical anomaly assessment index 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. Divide the long-term window into a front time zone and a back time zone based on the midpoint. Calculate the average value of the mechanical anomaly assessment index at each set time point within the front time zone, and record it as the front time mechanical value. Calculate the average value of the mechanical anomaly assessment index at each set time point within the back time zone, and record it as the back time mechanical value. Calculate the ratio of the back time mechanical value to the front time mechanical value to obtain the mechanical ratio of the circuit breaker within the long-term window.

[0037] Specifically, the mechanical transformation evaluation index of the circuit breaker within the current long-term window is obtained as follows:

[0038] For the subsequent mechanical value, a ratio is calculated between it and the preset mechanical abnormality threshold index, that is, the subsequent mechanical value is the numerator and the mechanical abnormality threshold index is the denominator; thus, the alarm distance value of the circuit breaker in the long-term window is obtained.

[0039] By comprehensively analyzing the stabilization value, mechanical ratio, and warning distance value of the circuit breaker within a long-term window, the mechanical transformation evaluation index of the circuit breaker within the current long-term window is obtained.

[0040] Specifically, the trend level of the output circuit breaker is as follows:

[0041] The mechanical transformation assessment index of the circuit breaker within the current long-term window is matched with the preset index threshold range. If the mechanical transformation assessment index is within the index threshold range, the trend level of the circuit breaker within the current long-term window is determined to be no obvious trend level; if the mechanical transformation assessment index is higher than the index threshold range, the trend level of the circuit breaker within the current long-term window is determined to be the trend maintenance level.

[0042] A circuit breaker fault diagnosis method includes:

[0043] File construction: Extract vibration and displacement data of the circuit breaker during the initial operation phase and construct the circuit breaker's health file;

[0044] Time zone setting: Set the evaluation time window for the circuit breaker, which includes a short-term window and a long-term window;

[0045] Anomaly Analysis: A comprehensive evaluation of the vibration and displacement data of the circuit breaker within a short-term window is conducted to obtain the mechanical anomaly assessment index of the circuit breaker within the current short-term window.

[0046] Historical data integration: If the mechanical anomaly assessment index of a circuit breaker is higher than the preset mechanical anomaly threshold index within a short-term window, an early warning signal is triggered, and abnormal cases are extracted from the database for similarity analysis. The abnormal cases with the highest confidence values ​​are selected, and the abnormal causes are extracted as the estimated causes for triggering the early warning signal of the current circuit breaker.

[0047] Long-term tracking: If the cumulative duration of the circuit breaker not triggering the early warning signal reaches the set long-term window duration, the time dimension 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 evaluation index of the circuit breaker within the current long-term window, thereby outputting the trend level of the circuit breaker.

[0048] The technical effects and advantages of this invention are as follows:

[0049] This invention obtains the mechanical anomaly assessment index of the circuit breaker by using 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, and combining the root mean square error of the travel length, average displacement velocity, and displacement-time curve. This enables a multi-dimensional assessment of the mechanical state of the circuit breaker. After triggering the warning signal, the initial similar cases are screened by the warning depth value. The parameters are transformed into coordinate points in a Cartesian coordinate system. The similarity between the current fault and the abnormal case is quantified by the line distance value and Euclidean distance, avoiding subjective judgment errors and improving the accuracy of anomaly cause prediction. This solves the problem that existing fault diagnosis technologies rely heavily on single-parameter analysis and cannot combine multi-parameter analysis results with historical data to quickly locate circuit breaker faults.

[0050] This invention comprehensively analyzes the three-dimensional parameters of the stabilization value, mechanical ratio, and alarm distance value within a long-term window when a time-dimensional change signal is triggered. It captures the gradual deterioration of the circuit breaker before it exceeds the threshold, matches the mechanical change evaluation index with a preset threshold, classifies the trend level, and intuitively displays the evolution of the equipment status. This provides data support for predictive maintenance and solves the problem that existing technologies lack effective means to monitor the long-term evolution trend of the mechanical status of circuit breakers, and often only focus on single-point detection of immediate anomalies.

[0051] This invention improves the accuracy of short-term window assessment of the mechanical condition of circuit breakers by recording mechanical data during the initial operation phase as a reference benchmark.

[0052] This invention effectively improves the accuracy, timeliness, and maintenance efficiency of circuit breaker fault diagnosis by extracting multi-dimensional fault features, accurately locating faults by integrating historical cases, and quantitatively evaluating long-term trends, thereby ensuring the stable operation of the power system. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of a circuit breaker fault diagnosis system according to the present invention;

[0054] Figure 2 This is a flowchart of a circuit breaker fault diagnosis method according to the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] Example 1

[0057] 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;

[0058] The baseline construction module utilizes, but is not limited to, vibration sensors, displacement sensors, stroke sensors, and speed sensors. Vibration sensors are installed on the mechanical transmission components and housing of the circuit breaker to collect mechanical vibration data during opening and closing operations and normal operation. Displacement sensors are used to monitor displacement changes in components such as contacts and transmission rods. Stroke sensors are used to record the opening and closing stroke of the contacts. Each sensor collects mechanical parameters in real time according to 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 preprocessing such as filtering and noise reduction.

[0059] 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 phase, and construct the health record of the circuit breaker.

[0060] Based on the recorded vibration and displacement data of the circuit breakers, a mechanical health record is constructed for each circuit breaker. The health record also includes basic information about the circuit breaker (model, specifications, installation time, manufacturer, etc.). When constructing the health record, the mechanical data of the initial operation phase (such as the first 72 hours) is statistically analyzed to calculate the real-time data, average value, standard deviation and other statistical quantities of various mechanical data to determine the reference value for normal operation.

[0061] Time-series analysis module: Technicians set the evaluation time window for the circuit breaker, which includes a short-term window and a long-term window; short-term window (10-30 minutes): captures sudden anomalies, long-term window (1-30 days): analyzes aging trends; the vibration data and displacement travel data of the circuit breaker within the short-term window are comprehensively evaluated to obtain the mechanical anomaly evaluation index Ete of the circuit breaker within the current short-term window;

[0062] Specifically:

[0063] For the vibration data of the circuit breaker within a short window, the time domain signal is extracted. The complete vibration process signal is extracted from the time domain signal according to the action sequence and denoted as discrete sequence x(n) (n=1,2,...,N,N is the number of sampling points). The original vibration signal is denoised and enhanced. Low-pass / high-pass filters are used to remove noise in specific frequency bands (such as power frequency interference), and median filtering is used to eliminate impulse noise.

[0064] Based on discrete sequences, using the formula Calculate the root mean square value It 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;

[0065] Based on discrete sequences, using the formula Calculate sheath strength ;in The mean, The standard deviation is used to measure the "peaking" of the signal amplitude distribution. Normal vibration signals follow a Gaussian distribution (kurtosis ≈ 3). When impact failures occur (such as abnormal contact collisions or bearing peeling), the kurtosis value increases significantly.

[0066] For time-domain waveform characteristics, the number of times the signal crosses zero level within a short-term window is counted and the frequency is calculated. This is done by dividing the number of crossings by the short-term window value, and the calculated frequency is recorded as the zero-crossing frequency. Abnormal zero-crossing frequencies may correspond to disordered vibration frequencies.

[0067] The time-domain signal is converted to the frequency domain using a Fast Fourier Transform (FFT) to obtain the spectral amplitude; the frequency point with the largest amplitude in the spectrum is recorded as the main frequency. ;

[0068] The rules for dividing the high-frequency band are preset; frequencies greater than 10kHz can be defined as the high-frequency band; high frequencies are divided from the frequency domain, and the proportion of high-frequency energy to the total energy is calculated and denoted as the high-frequency energy percentage. If the energy in the high-frequency band surges compared to normal operation, it indicates localized impact or friction (such as contact wear).

[0069] To elaborate further, by using time-domain parameters such as root mean square (RMS), kurtosis, and zero-crossing frequency, as well as frequency-domain parameters such as dominant frequency and high-frequency energy ratio, vibration signal characteristics can be captured from different dimensions. For example, the RMS value reflects the intensity of continuous vibration, kurtosis is sensitive to impact faults, and dominant frequency and high-frequency energy ratio reveal frequency component anomalies, thus forming a three-dimensional characterization of the mechanical state of the circuit breaker.

[0070] The root mean square value is estimated based on the vibration data of the circuit breaker within a short-term window. Sheath length Zero crossing frequency , main frequency and the proportion of high-frequency energy Extract 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 circuit breaker's health record, and record them as follows: ;

[0071] The initial running phase can be divided into sub-running zones according to the duration of the short-term window. The average values ​​of the root mean square value, sheath strength, zero-crossing frequency, dominant frequency, and high-frequency energy ratio in each sub-running zone can be calculated and used as reference root mean square value, reference sheath strength, reference zero-crossing frequency, reference dominant frequency, and reference high-frequency energy ratio.

[0072] Additional notes: Reference values ​​(such as root mean square value, kurtosis, etc.) for the initial operation phase are extracted from the health records, and the effects of equipment manufacturing differences and installation errors are eliminated by calculating the average value of the sub-operational zones.

[0073] Using formula A comprehensive calculation is performed to determine the vibration risk value of the circuit breaker within the short-term window. ;in These are the root mean square values. Sheath length Zero crossing frequency , main frequency and the proportion of high-frequency energy The corresponding weighting coefficients;

[0074] To elaborate further, the vibration hazard 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 cumulative effect of faults more comprehensively than a single parameter. The larger the vibration hazard value, the more the parameter deviates from the reference value, and the higher the risk of mechanical faults.

[0075] For the displacement travel data of the circuit breaker within a short window, extract the travel length and travel time during the opening and closing process;

[0076] The average displacement velocity of the circuit breaker is obtained by calculating the ratio of the travel length to the travel time.

[0077] If the average displacement velocity deviates significantly from normal conditions, it indicates a poor mechanical condition. Reasons could include:

[0078] Possible reasons for low average speed

[0079] Mechanical jamming or increased resistance: such as poor lubrication of the transmission rod, aging of the contact spring, deformation of the mechanism components, etc., which leads to a longer action time, and the total displacement may be reduced due to insufficient stroke, ultimately reducing the average speed;

[0080] Insufficient power source: such as a decrease in the energy output of the operating mechanism (e.g., spring-operated, hydraulically operated), which cannot drive the components to reach the normal speed. For example, spring fatigue in the spring operating mechanism results in insufficient energy when closing the circuit, leading to a low closing speed.

[0081] Possible reasons for higher average speed

[0082] Reduced mechanical resistance or loose components: such as excessive clearance in transmission components or loose fixing bolts, which leads to reduced frictional resistance and abnormally increased speed during operation;

[0083] Extract the displacement-time curve during the circuit breaker's opening and closing process, and extract the standard opening and closing stroke length, average normal displacement speed, and normal displacement-time curve determined during the initial operation phase from the circuit breaker's health record.

[0084] During the initial operation phase of the circuit breaker, 20 opening and closing displacement data points can be collected. The average stroke length during each opening and closing process can be calculated as the standard opening and closing stroke length; the average displacement velocity during each opening and closing process can be calculated as the normal average displacement velocity; and the fitting curve of the displacement-time curve during each opening and closing process can be obtained by fitting the 20 displacement curves at the same time point. Calculate the mean and use the mean of each group to build a curve;

[0085] Time alignment is performed between the current displacement curve and the normal displacement-time curve; the action trigger time is used as the reference; the root mean square error is calculated after alignment. The formula is expressed as c represents the total number of time points during the opening and closing process, and i represents the time point number. An increase indicates that the motion trajectory deviates from the normal state, which may be caused by wear and tear of mechanical parts or loose connections;

[0086] Using formula A comprehensive calculation is performed to determine the hazard value of the circuit breaker within the short-term window. ; These represent the stroke length and average displacement velocity, respectively. These represent the standard opening and closing stroke length and the average velocity of normal displacement, respectively. These are the weighting coefficients set for the root mean square error, stroke length, and average displacement velocity, respectively.

[0087] In addition, by combining core parameters such as stroke length, average displacement velocity, and root mean square error of displacement-time curve, an evaluation system is constructed from three dimensions: "whether the stroke length deviates", "whether the motion speed is normal", and "whether the motion trajectory deviates", to avoid the one-sidedness of single parameter analysis.

[0088] Extracting vibration risk values ​​of circuit breakers within a short-term window and the value of the disease And substitute into the formula A comprehensive calculation was performed to obtain the mechanical anomaly assessment index Ete of the circuit breaker within the short-term window; where... These are the vibration values. and the value of the disease The corresponding weighting coefficients;

[0089] In addition, the calculated mechanical anomaly assessment index Ete can avoid one-sidedness and cover multiple failure modes.

[0090] A single parameter (such as only looking at vibration kurtosis or only looking at displacement velocity) may lead to misjudgment due to the superposition of faults or parameter coupling. For example, contact wear may simultaneously cause a surge in high-frequency vibration energy (increased vibration fault value) and insufficient displacement stroke (increased displacement fault value). Mechanical jamming will cause a decrease in displacement velocity (abnormal displacement fault value), accompanied by an increase in vibration intensity (abnormal vibration fault value). Comprehensive evaluation can eliminate interference from a single factor.

[0091] Case combination module: If the mechanical anomaly assessment index Ete of the circuit breaker is higher than the preset mechanical anomaly threshold index within a certain short window, an early warning signal is triggered and the circuit breaker anomaly cases that match the basic information of the current circuit breaker are extracted from the database for similarity analysis. Each group of circuit breaker anomaly cases includes the occurrence time, the cause of the anomaly, and the personnel handling it. Based on the similarity analysis results, the anomaly case with the highest confidence value is selected from the matched circuit breaker anomaly cases, and the cause of the anomaly is extracted as the estimated cause of the current circuit breaker triggering the early warning signal.

[0092] Specifically:

[0093] After the warning signal is triggered, the difference between the mechanical anomaly assessment index Ete and the mechanical anomaly threshold index is calculated and recorded as the warning depth value.

[0094] For matched abnormal cases, the difference between the warning depth value of each group of abnormal cases and the warning depth value of the current triggering warning signal is calculated, and the absolute value is taken to obtain the exponential difference value; the exponential difference value calculated for each group of abnormal cases is compared with the set difference threshold, and abnormal cases with exponential difference values ​​lower than the difference threshold are retained as initial similar cases.

[0095] As a supplementary explanation, setting a difference threshold (such as 0.5) and retaining cases with index difference values ​​below this threshold can eliminate historical cases with significantly different warning levels.

[0096] For example, if the warning depth value of historical cases is 2, the current value is 4.8, and the index difference value is 2.8, cases that are higher than the threshold will be filtered out, and only cases with similar warning levels (such as index difference value ≤ 0.5) will be retained. This will make the screening results more focused on "faults of the same level" and improve the reliability of subsequent cause prediction.

[0097] The mechanical difference assessment index is extracted from the initial similar cases, and the vibration hazard value and the kinetic hazard value of the initial similar cases are obtained by analysis, with the vibration hazard value and the kinetic hazard value as the horizontal axis and the vertical axis, respectively.

[0098] Construct a Cartesian coordinate system and plot the coordinates of the x and y coordinates of each group of initial similar cases in the Cartesian coordinate system, which will be used as case points;

[0099] Based on the current vibration value that triggered the early warning signal and the value of the disease The coordinates of these points, which are used as the x and y coordinates and plotted on a Cartesian coordinate system, serve as signaling points.

[0100] Starting from the signaling point, construct straight line segments between the signaling point and each group of case points, and obtain the length of the straight line segments as the line distance value of each group of initial similar cases. ;

[0101] To elaborate further, by using vibration fault values ​​(vibration characteristics) and travel fault values ​​(travel characteristics) as two-dimensional coordinates, a "vibration-travel" dual-parameter fault mapping system is formed. Compared with a single parameter (such as using only vibration fault values ​​or travel fault values), it can more comprehensively characterize the multidimensional features of mechanical faults (such as the correlation between vibration abnormalities and travel deviations).

[0102] By converting historical cases and current signaling points into coordinate points using a Cartesian coordinate system, the parameter distribution patterns of different fault types can be intuitively displayed, making it easier to quickly identify similar fault modes. The line segment 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 kinetic values ​​are to the historical case, and the higher the similarity of the fault cause.

[0103] The vibration and motion hazard values ​​of the initial similar cases are analyzed to obtain the root mean square value, sheath length, zero-crossing frequency, dominant frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement velocity of the initial similar cases; and compared with the root mean square value of the current trigger warning signal. Sheath length Zero crossing frequency , main frequency High-frequency energy ratio Root mean square error Length of trip and average displacement velocity Distance values ​​are calculated using Euclidean distance. Calculation;

[0104] Based on the root mean square value, sheath length, zero-crossing frequency, dominant frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement velocity of the current triggering warning signal, an 8-dimensional parameter vector P = (m1, m2, ..., m8) is constructed; and an 8-dimensional parameter vector H = (w1, w2, ..., w8) is constructed for the initial similar cases.

[0105] The formula is expressed as ; s is the index of each parameter in the 8-dimensional parameter vector;

[0106] Using formula The confidence value Lt of each group of initial similar cases was calculated; where These are the line spacing values. and distance value The corresponding weighting coefficients;

[0107] For each group of initial similar cases, the initial similar cases with larger confidence values ​​Lt are extracted as reference cases for triggering the current warning signaling, and the abnormal reasons for triggering the warning signaling in the reference cases are used as the estimated reasons for triggering the current circuit breaker warning signaling.

[0108] To elaborate further, the confidence value calculation integrates the line distance value (two-dimensional coordinate distance) of the two parameters "vibration-stroke" and the Euclidean distance of the 8-dimensional parameter vector (including root mean square value, sheath degree, zero crossing frequency and other subdivided features), combining the macroscopic features of mechanical faults (such as the correlation between vibration and stroke) with microscopic features (such as the proportion of high-frequency energy, displacement velocity, etc.), thus avoiding the one-sidedness of single parameter analysis.

[0109] The smaller the line spacing and Euclidean distance values, the closer the current fault parameters are to historical cases, and the larger the confidence value Lt is. Through quantitative calculation, the "similarity" is converted into a comparable value, avoiding the error of subjective judgment.

[0110] Long-term diagnostic module: If the cumulative duration of the circuit breaker not triggering the early warning signal reaches the set long-term window duration, 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 evaluation index of the circuit breaker within the current long-term window, thereby outputting the trend level of the circuit breaker; the trend level includes no obvious trend level and trend maintenance level.

[0111] Additional explanation: If the triggering of the time-dimensional change signaling indicates that the circuit breaker has not experienced any abnormal mechanical state for a long time, but for the sake of long-term stable operation of the circuit breaker, it is necessary to capture the slight changes in mechanical parameters and determine whether there is a trend of mechanical abnormality.

[0112] Specifically:

[0113] After triggering the time-dimensional change signaling, 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;

[0114] The mechanical anomaly assessment index Ete is extracted at each set time point within the long-term window, and the standard deviation is calculated to obtain the stabilization value of the circuit breaker within the long-term window; this measures the degree of data dispersion and reflects the trend stability. If the stabilization value is large, it indicates that the mechanical state stability of the circuit breaker within the long-term window is poor.

[0115] The long-term window is divided into a front time zone and a back time zone based on the midpoint. The average value of the mechanical anomaly assessment 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 anomaly assessment index Ete at each set time point in the back time zone is calculated and recorded as the back time mechanical value.

[0116] The mechanical ratio of the circuit breaker in the long-term window is obtained by calculating the ratio of the mechanical value of the later time to the numerator and the mechanical value of the earlier time to the denominator.

[0117] Additional explanation: The size of the machine ratio reflects:

[0118] The ratio of mechanical parts is greater than 1:

[0119] The average Ete in the later time zone is higher than that in the earlier time zone, indicating that the mechanical condition assessment index is on the rise. Since Ete is usually positively correlated with the degree of mechanical abnormality (such as abnormal vibration, travel deviation, etc.), this trend may reflect the progressive deterioration of the mechanical components of the circuit breaker (such as increased wear, loosening of components, etc.). Although no warning signal was triggered, there is a potential risk of failure.

[0120] The ratio of mechanical parts is close to 1:

[0121] The average Ete value did not change significantly between the previous and next time zones, indicating that the mechanical condition was relatively stable.

[0122] Mechanical ratio <1:

[0123] The average Ete in the later time zone is lower than that in the earlier time zone, indicating that the mechanical condition tends to improve (such as the disappearance of accidental interference and the self-healing of minor abnormalities).

[0124] The mechanical ratio transforms the "time-dimensional parameter changes" into quantifiable trend indicators by comparing the mechanical condition assessment index of the time period before and after the long-term window. Its essence is to capture the gradual evolution law of mechanical condition and provide data support for the predictive maintenance of circuit breakers.

[0125] For the subsequent mechanical value, a ratio is calculated between it and the preset mechanical anomaly threshold index, i.e., the subsequent mechanical value is the numerator and the mechanical anomaly threshold index is the denominator; the alarm distance value of the circuit breaker in the long-term window is obtained; the closer the alarm distance value is to 1, the faster the circuit breaker is close to triggering the warning signal.

[0126] Extract the circuit breaker's stabilization value, mechanical ratio, and warning distance value within a long-term window, and label them as follows: Using formulas The stabilization value, mechanical ratio, and warning distance of the circuit breaker within the long-term window are comprehensively calculated to obtain the mechanical change evaluation index Kq of the circuit breaker within the current long-term window. These are the weighting coefficients corresponding to the stabilization value, the weapon ratio value, and the police distance value, respectively.

[0127] Additional explanation,

[0128] Breaking through the limitations of single-point detection: Traditional early warning only focuses on immediate anomalies (such as Ete exceeding the threshold), while Kq can capture potential risks that have not exceeded the threshold but continue to deteriorate (such as progressive wear of bearings and loss of spring elasticity) by analyzing the stability (stabilization value) of long-term data, trend direction (machine ratio value), and threshold distance (warning distance value).

[0129] Match the mechanical transformation evaluation index Kq of the circuit breaker within the current long-term window with the preset index threshold range. If the mechanical transformation evaluation index Kq is within the index threshold range, then the trend level of the circuit breaker within the current long-term window is determined to be no obvious trend level.

[0130] If the mechanical transformation assessment index Kq is higher than the index threshold range, the trend level of the circuit breaker within the current long-term window will be determined as the trend maintenance level.

[0131] 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;

[0132] Additional explanation: The mechanical damage assessment index is matched with preset thresholds to classify the levels into "no obvious trend level" and "trend maintenance level," thereby achieving differentiated maintenance strategies.

[0133] For devices showing no clear trend, extend the monitoring cycle to reduce unnecessary maintenance costs;

[0134] For "trend maintenance" equipment, location information and maintenance level are proactively pushed to guide maintenance personnel to perform precise operations, avoid blind inspections, and improve maintenance efficiency; Example

[0135] Please see Figure 2 As shown, based on the circuit breaker fault diagnosis system provided in Embodiment 1 of this application, Embodiment 2 of this application proposes a circuit breaker fault diagnosis method. Embodiment 2 is merely a preferred embodiment of Embodiment 1, and the implementation of Embodiment 2 will not affect the individual implementation of Embodiment 1.

[0136] Specifically, the circuit breaker fault diagnosis method provided in Embodiment 2 of this application differs in that it includes:

[0137] File construction: Extract vibration and displacement data of the circuit breaker during the initial operation phase and construct the circuit breaker's health file;

[0138] Time zone setting: Set the evaluation time window for the circuit breaker, which includes a short-term window and a long-term window;

[0139] Anomaly Analysis: A comprehensive evaluation of the vibration and displacement data of the circuit breaker within a short-term window is conducted to obtain the mechanical anomaly assessment index of the circuit breaker within the current short-term window.

[0140] Historical data integration: If the mechanical anomaly assessment index Ete of the circuit breaker is higher than the preset mechanical anomaly threshold index within a certain short-term window, an early warning signal is triggered and abnormal cases are extracted from the database for similarity analysis. The abnormal cases with the highest confidence value are selected, and the abnormal causes are extracted from them as the estimated causes for the current circuit breaker to trigger the early warning signal.

[0141] Long-term tracking: If the cumulative duration of the circuit breaker not triggering the warning signal reaches the set long-term window duration, the time dimension 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 evaluation index of the circuit breaker within the current long-term window, thereby outputting the trend level of the circuit breaker.

[0142] The above formulas are all dimensionless calculations. Dimensionless calculations can be performed using various methods such as standardization, which will not be elaborated here. The formulas are derived from software simulations based on a large amount of collected data, and the preset parameters in the formulas can be set by those skilled in the art according to the actual situation.

[0143] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. 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 (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, ATA hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium can be a solid-state ATA hard disk.

[0144] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply 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 this application.

[0145] Those skilled in the art will recognize that the units and algorithm steps of the various examples 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 implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art 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.

[0146] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0147] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0148] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0149] If the aforementioned functions are implemented as 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 this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable ATA hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0150] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A circuit breaker failure diagnosis system characterized by, Includes the following modules: Benchmark building module: Records the mechanical data of the circuit breaker during the initial operation phase and builds the circuit breaker's health profile; the mechanical data includes vibration data and displacement travel data; Time sequence analysis module: Set the evaluation time window for the circuit breaker, which includes a short-term window and a long-term window. Perform a comprehensive evaluation of the mechanical data of the circuit breaker within the short-term window to obtain the mechanical anomaly evaluation index of the circuit breaker corresponding to the current short-term window. Specifically: For the vibration data of the circuit breaker within a short window, the time domain signal is extracted, and the complete vibration process signal is extracted from the time domain signal and denoted as the discrete sequence x(n) (n=1,2,...,N,N is the number of sampling points). Based on the discrete sequence, the root mean square value and sheath strength are calculated. For time-domain waveform characteristics, count the number of times the signal crosses zero level within a short window and calculate the frequency, then record the calculated frequency as the zero-crossing frequency; convert the time-domain signal to the frequency domain to obtain the spectral amplitude; and record the frequency point with the largest amplitude in the spectrum as the main frequency. By setting a high-frequency threshold, 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 the high-frequency energy percentage. The root mean square value, sheath length, zero-crossing frequency, dominant frequency, and high-frequency energy ratio are evaluated based on the vibration data of the circuit breaker within a short-term window. Extract 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 circuit breaker's health record, and denote them as follows: The root mean square value, sheath strength, zero-crossing frequency, dominant frequency, and high-frequency energy ratio of the vibration data of the circuit breaker within the short-term window are evaluated and combined with the corresponding reference root mean square value, reference sheath strength, reference zero-crossing frequency, reference dominant frequency, and reference high-frequency energy ratio for comprehensive analysis, so as to determine the vibration risk value of the circuit breaker within the short-term window. Using formula A comprehensive calculation is performed to determine the vibration risk value of the circuit breaker within the short-term window. ;in These are the root mean square values. Sheath length Zero crossing frequency , main frequency and the proportion of high-frequency energy The corresponding weighting coefficients; For the displacement travel data of the circuit breaker within a short window, the travel length and travel time during the opening and closing process are extracted; the ratio of 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's opening and closing process. Extract the standard opening and closing stroke length, average normal displacement speed, and normal displacement-time curve determined during the initial operation phase from the circuit breaker's health record. Perform time alignment between the current displacement curve and the normal displacement-time curve, and calculate the root mean square error after alignment. The root mean square error, stroke length, and average displacement speed of the circuit breaker are comprehensively analyzed in conjunction with the corresponding standard opening and closing stroke length, normal average displacement speed, and normal displacement time curve to determine the hazard value of the circuit breaker within the short-term window. Using formula A comprehensive calculation is performed to determine the hazard value of the circuit breaker within the short-term window. ; Indicates the root mean square error; These represent the stroke length and average displacement velocity, respectively. These represent the standard opening and closing stroke length and the average velocity of normal displacement, respectively. These are the weighting coefficients set for the root mean square error, stroke length, and average displacement velocity, respectively. Extracting vibration risk values ​​of circuit breakers within a short-term window and the value of the disease And substitute into the formula A comprehensive calculation was performed to obtain the mechanical anomaly assessment index Ete of the circuit breaker within the short-term window; where... These are the vibration values. and the value of the disease The corresponding weighting coefficients; Case combination module: If the mechanical anomaly assessment index of the circuit breaker is higher than the preset mechanical anomaly threshold index within a short window, an early warning signal is triggered. The current mechanical anomaly assessment index of the circuit breaker is input into the database for screening and matching of abnormal cases. The abnormal case with the highest confidence value is selected from the matched abnormal cases, and the abnormal cause is extracted as the estimated cause of the current circuit breaker triggering the early warning signal. Long-term diagnostic module: If the cumulative duration of the circuit breaker not triggering the early warning signal reaches the set long-term window duration, the time dimension change signal is triggered to comprehensively evaluate the mechanical data of the circuit breaker within the long-term window, obtain the mechanical change evaluation index of the circuit breaker within the current long-term window, and output the trend level of the circuit breaker. The trend levels include no obvious trend level and trend maintenance level.

2. The circuit breaker fault diagnostic system of claim 1, wherein, The step of inputting the mechanical anomaly assessment index of the current circuit breaker into the database for screening and matching abnormal cases is as follows: The difference between the mechanical abnormality assessment index and the mechanical abnormality threshold index is calculated and recorded as the warning depth value; For matched abnormal cases, the difference between the warning depth value of each group of abnormal cases and the warning depth value of the current triggering warning signal is calculated, and the absolute value is taken to obtain the exponential difference value. The exponential difference value calculated for each group of abnormal cases is compared with the set difference threshold, and abnormal cases with exponential difference values ​​lower than the difference threshold are retained as initial similar cases.

3. The circuit breaker fault diagnostic system of claim 2, wherein, The process of selecting the anomaly case with the highest confidence value from the matched anomaly cases is as follows: The mechanical difference assessment index is extracted from the initial similar cases, and the vibration and lateral hazard values ​​of the initial similar cases are obtained by analysis. The vibration and lateral hazard values ​​are used as the horizontal and vertical axes, respectively, to analyze and obtain the line distance values ​​of each group of initial similar cases. The vibration and motion hazard values ​​of the initial similar cases are analyzed to obtain the root mean square value, sheath length, zero-crossing frequency, dominant frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement velocity of the initial similar cases. The distance value is calculated using Euclidean distance between the current root mean square value, sheath length, zero-crossing frequency, main frequency, high-frequency energy ratio, root mean square error, stroke length, and average displacement velocity that trigger the early warning signal; a comprehensive analysis of the line spacing value and the distance value is performed to obtain the confidence value of each group of initial similar cases; For each group of initial similar cases, the initial similar cases with higher confidence values ​​are extracted as reference cases for triggering the current warning signaling, and the abnormal reasons for triggering the warning signaling in the reference cases are used as the estimated reasons for triggering the current circuit breaker warning signaling.

4. The circuit breaker fault diagnostic system of claim 3, wherein, The line spacing values ​​for each group of initial similar cases are obtained as follows: Construct a Cartesian coordinate system, plot the coordinates of each initial similar case in the Cartesian coordinate system, and use them as case points; use the vibration and motion values ​​of the current triggering warning signal as the coordinates of the Cartesian coordinate system, and plot them as signal points. Starting from the signaling 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.

5. The circuit breaker fault diagnostic system of claim 1, wherein, The comprehensive evaluation of the vibration and displacement data of the circuit breaker within the long-term window is as follows: After triggering the time-dimensional change signaling, the vibration data and displacement stroke data of the circuit breaker within the long-term window are analyzed to obtain the mechanical anomaly evaluation index at each set time point within the long-term window; Extract the mechanical anomaly assessment index 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. Divide the long-term window into a pre-time zone and a post-time zone based on the midpoint. Calculate the average value of the mechanical anomaly assessment index at each set time point within the pre-time zone, and record it as the pre-time mechanical value. Calculate the average value of the mechanical anomaly assessment index at each set time point within the post-time zone, and record it as the post-time mechanical value. Calculate the ratio of the post-time mechanical value to the pre-time mechanical value to obtain the mechanical ratio of the circuit breaker within the long-term window.

6. The circuit breaker fault diagnostic system of claim 5, wherein, The obtained mechanical transformation evaluation index for the circuit breaker within the current long-term window is specifically as follows: For the subsequent mechanical value, a ratio is calculated between it and the preset mechanical abnormality threshold index, that is, the subsequent mechanical value is the numerator and the mechanical abnormality threshold index is the denominator; thus, the alarm distance value of the circuit breaker in the long-term window is obtained. By comprehensively analyzing the stabilization value, mechanical ratio, and warning distance value of the circuit breaker within a long-term window, the mechanical transformation evaluation index of the circuit breaker within the current long-term window is obtained.

7. The circuit breaker fault diagnostic system of claim 6, wherein, The trend level of the output circuit breaker is specifically as follows: The mechanical transformation assessment index of the circuit breaker within the current long-term window is matched with the preset index threshold range. If the mechanical transformation assessment index is within the index threshold range, the trend level of the circuit breaker within the current long-term window is determined to be no obvious trend level; if the mechanical transformation assessment index is higher than the index threshold range, the trend level of the circuit breaker within the current long-term window is determined to be the trend maintenance level.

8. A circuit breaker fault diagnosis method applied to the circuit breaker fault diagnosis system of any one of claims 1-7, characterized in that, include: File construction: Extract vibration and displacement data of the circuit breaker during the initial operation phase and construct the circuit breaker's health file; Time zone setting: Set the evaluation time window for the circuit breaker, which includes a short-term window and a long-term window; Anomaly Analysis: A comprehensive evaluation of the vibration and displacement data of the circuit breaker within a short-term window is conducted to obtain the mechanical anomaly assessment index of the circuit breaker within the current short-term window. Historical data integration: If the mechanical anomaly assessment index of a circuit breaker is higher than the preset mechanical anomaly threshold index within a short-term window, an early warning signal is triggered, and abnormal cases are extracted from the database for similarity analysis. The abnormal cases with the highest confidence values ​​are selected, and the abnormal causes are extracted as the estimated causes for triggering the early warning signal of the current circuit breaker. Long-term tracking: If the cumulative duration of the circuit breaker not triggering the early warning signal reaches the set long-term window duration, the time dimension 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 evaluation index of the circuit breaker within the current long-term window, thereby outputting the trend level of the circuit breaker.

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