Fault arc circuit breaker quality evaluation system

Abstract

The invention particularly relates to a fault arc circuit breaker quality evaluation system. The system comprises an arc extinguish chamber evaluation module; a fault current simulation module; the test module is used for combining an arc extinguish chamber evaluation index and a response delay index obtained after the circuit breaker is subjected to response action test with a temperature qualification index of the electromagnetic element to obtain a quality difference coefficient; and a quality grade judgment module. According to the invention, the arc extinguish chamber evaluation module is started from two aspects of shell integrity and arc extinguish medium stability, utilizes a defect crossing value to reflect shell crack and damage distribution, measures conditions of arc extinguish medium leakage and the like by means of a medium unbalance value, and comprehensively considers the state of the arc extinguish chamber; the fault current simulation module accurately simulates fault current characteristics, calculates a response delay index and evaluates the fault response speed of the circuit breaker; and the quality difference coefficient is finally obtained by combining the temperature qualification index of the electromagnetic element, accurate and comprehensive evaluation of the quality of the circuit breaker is realized by multi-dimensional data fusion, and evaluation deviation caused by single index judgment is avoided.

Description

Technical Field

[0001] The present invention relates to the field of power equipment detection technology, and in particular to a fault arc circuit breaker quality assessment system. Background Art

[0002] Arc fault circuit breakers are key equipment for ensuring safety in power systems, and their quality is directly related to the stable operation of the power system and the safety of personnel and equipment.

[0003] However, there are many shortcomings in the current quality assessment methods for arc fault circuit breakers.

[0004] Traditional evaluation models often focus on a single performance indicator, such as simply considering the arc extinguishing ability of the arc extinguishing chamber. This only focuses on whether the arc extinguishing chamber can quickly and effectively extinguish the arc under specific standard test conditions, while ignoring the structural integrity issues that may arise in the arc extinguishing chamber housing during long-term operation. Cracks and damage to the casing caused by environmental factors, mechanical stress, etc. These defects may affect the sealing and insulation performance of the arc extinguishing chamber, thereby having an indirect but significant impact on the arc extinguishing effect; Another example is that we only focus on the circuit breaker's operating time, that is, the time from the detection of the fault signal to the action of the contacts to cut off the circuit, while ignoring the comprehensive impact of the fault current characteristics on the circuit breaker's response. Fault currents with different amplitudes, change rates and frequency components may cause changes in the working conditions of the circuit breaker's internal electromagnetic components, tripping mechanisms, etc., affecting the overall performance.

[0005] This may result in some circuit breakers with potential quality problems not being discovered in time during actual use, and thus failing to effectively play a protective role when a fault occurs, causing serious power accidents.

[0006] Therefore, there is a need for a system that can evaluate the quality of an arc fault circuit breaker by simulating the changes of the arc fault circuit breaker itself during operation to evaluate the quality of the arc fault circuit breaker. Summary of the Invention

[0007] The purpose of the present invention is to solve the above problems and to propose a quality assessment system for arc fault circuit breakers.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: A quality assessment system for an arc fault circuit breaker, comprising: Arc extinguishing chamber evaluation module: collects relevant information of the arc extinguishing chamber, and obtains the arc extinguishing chamber evaluation index after analysis and processing; Fault current simulation module: simulates fault current to test the fault response of the circuit breaker and obtain the response delay index; Testing module: The arc extinguishing chamber evaluation index and response delay index obtained after the circuit breaker response action test are combined with the temperature qualification index of the electromagnetic component to obtain the quality gap coefficient; Quality grade judgment module: Analyze the quality gap coefficient obtained after simulating the fault current to obtain the quality grade coefficient, and perform quality rating on the circuit breaker based on the quality grade coefficient.

[0009] Preferably, the arc extinguishing chamber evaluation index acquisition includes the following parts: Collecting relevant information of the arc extinguishing chamber including the image information of the arc extinguishing chamber shell and relevant information of the arc extinguishing medium; The defect span value is obtained by analyzing the image information of the arc extinguishing chamber shell; The medium imbalance value is obtained by analyzing the information related to the arc extinguishing medium; The arc extinguishing chamber evaluation index is obtained by comprehensively processing the defect crossing value and the dielectric imbalance value.

[0010] Preferably, the defect span value is obtained in the following manner: Dividing the outer shell of the arc extinguishing chamber into sub-regions according to the set area, and obtaining image information of each sub-region of the outer shell of the arc extinguishing chamber; Extracting features related to cracks and damage from the image information in each sub-region and marking the extracted features as crack regions and damage regions in each sub-region of the arc extinguishing chamber shell; performing pixel count on the marked crack regions and damage regions in each sub-region of the circuit breaker, and calculating the number of pixels in the crack regions and damage regions in each sub-region of the arc extinguishing chamber shell; Based on the resolution of the image, the number of pixels of the crack area and the damaged area in each sub-area of the arc extinguishing chamber shell is converted into the actual area to obtain the crack area and damaged area in each sub-area of the circuit breaker; Arrange the crack area and damage area in each sub-region in descending order; and extract the maximum crack area, minimum crack area, maximum damage area, and minimum damage area; Determine the locations of the regions corresponding to the maximum crack area, the minimum crack area, the maximum damage area, and the minimum damage area; Connect the centers of the regions corresponding to the maximum crack area and the minimum crack area with a straight line, and obtain the length of the straight line and record it as the crack span; Connect the centers of the areas corresponding to the maximum and minimum damaged areas with a straight line, and obtain the length of the straight line as the damage span; The defect span value is obtained by weighting the crack span and damage span.

[0011] Preferably, the method for obtaining the medium imbalance value includes: The pressure of the arc extinguishing medium is obtained at preset time intervals, and the arc extinguishing medium pressure at each time point is compared with the corresponding time point according to the time series, with time as the horizontal axis and pressure as the vertical axis to establish a time-pressure line graph; Obtain the angle between the straight line between adjacent arc extinguishing medium pressure value points and the horizontal line. If the angle is acute, it is recorded as a descending slope; if the angle is obtuse, it is recorded as an ascending slope. Obtain all rising slopes and falling slopes, and sum up all falling slopes and rising slopes respectively to obtain the total falling slope and the total rising slope; Divide the total descending slope by the total ascending slope to obtain the leakage degree; Arrange a preset number of detection points around the arc extinguishing chamber, obtain the gas composition and content detected at each detection point at each time point, compare the gas composition with the arc extinguishing medium, and record the matching gas as the leakage medium; The concentration of the leaked medium detected at each detection point at the same time point is averaged to obtain the average leakage concentration; Multiply the mean leakage concentration by the number of detection points where the leaked medium was detected, and then multiply the result by the time between the first and last detection points to obtain the leakage value. The medium imbalance value is obtained by comprehensively analyzing the leakage degree and leakage amount values.

[0012] Preferably, simulating a fault current to test the fault response action of the circuit breaker and obtaining a response delay index specifically includes: After determining the signal characteristics of the fault current, a simulation signal is generated to conduct a power-on test on the circuit breaker; The time point when the circuit breaker is powered on is marked as the first time point, and the time point when the contact responds after the first time point is marked as the second time point; The time point at which the tripping mechanism controls the contact system of the circuit breaker to separate from the locking device after the second time point is marked as a third time point; Obtain the time difference between the first time point and the second time point, and record it as the previous time difference; The time difference between the first time point and the third time point is recorded as the total time difference; The time difference between the second time point and the third time point is recorded as the subsequent time difference; Substitute the previous time difference, the total time difference, and the next time difference into the formula to calculate the response delay index.

[0013] Preferably, obtaining the temperature qualification index of the electromagnetic component includes: Obtain the temperature of the electromagnetic element before the first time point, and record it as the initial temperature; Obtain the temperature of the electromagnetic element at the third time point, which is recorded as the late temperature; Subtract the initial temperature from the later temperature to get the temperature difference; Preset the temperature difference allowable range, match the temperature difference with the temperature difference allowable range, and record the temperature difference within the temperature difference allowable range as a positive temperature difference; The temperature difference is divided by the total time difference to obtain the heating rate; an allowable range of the heating rate is preset, and the heating rate within the allowable range is recorded as the normal heating rate; The temperature qualification index is obtained by weighted calculation of the positive temperature difference and the normal heating rate.

[0014] Preferably, the process of obtaining the mass gap coefficient includes: After normalizing the arc extinguishing chamber evaluation index, response delay index, and temperature qualified index, a three-dimensional rectangle is constructed using the arc extinguishing chamber evaluation index, response delay index, and temperature qualified index as length, width, and height, respectively; Connect the centers of the bottom and top of the three-dimensional rectangle with a straight line, determine the center of the straight line and use it as the center of the circle, construct a sphere with half the temperature qualification index as the radius, cut the three-dimensional rectangle, and calculate the volume of the remaining part of the three-dimensional rectangle as the mass gap coefficient.

[0015] Preferably, the quality gap coefficient obtained after simulating the fault current is analyzed to obtain the quality grade coefficient: Preset the number of simulated fault currents and obtain the quality gap coefficient after each simulated fault current; Draw a line graph with the number of simulated fault currents as the horizontal axis and the quality gap coefficient as the vertical axis, and mark the points corresponding to each quality gap coefficient on the line graph; analyze the quality gap coefficient on the line graph to obtain the trend degree; The average of the quality difference coefficients is calculated by averaging the obtained quality difference coefficients; The quality gap coefficient obtained after the last fault current simulation is extracted, and the difference between it and the quality gap coefficient obtained after the first fault current simulation is calculated to obtain the extreme value of the quality gap coefficient; The quality grade coefficient is obtained by comprehensively analyzing the trend degree, the mean value of the quality difference coefficient and the extreme value of the quality difference coefficient.

[0016] Preferably, the circuit breaker is rated according to the quality grade coefficient: Three groups of threshold value ranges are preset, each group of threshold value ranges corresponds to a quality level, and the quality level coefficient is matched with the three groups of threshold value ranges to obtain the quality level corresponding to the quality level coefficient; the quality levels include qualified, defective, and unqualified.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention uses an arc extinguishing chamber evaluation module to evaluate the integrity of the casing and the stability of the arc extinguishing medium. It uses the defect span value to reflect the distribution of cracks and damage in the casing, and uses the medium imbalance value to measure the leakage of the arc extinguishing medium, comprehensively considering the arc extinguishing chamber status. The fault current simulation module accurately simulates the fault current characteristics and calculates the response delay index to evaluate the fault response speed of the circuit breaker. Combined with the electromagnetic component temperature qualification index, the quality gap coefficient is finally derived. Multi-dimensional data fusion realizes an accurate and comprehensive evaluation of the circuit breaker quality, avoiding the evaluation deviation caused by the judgment of a single indicator.

[0018] 2. In the present invention, maintenance personnel can formulate targeted maintenance strategies based on the defect span value obtained by the arc extinguishing chamber evaluation module. Small defect span values correspond to local repairs, and large defect span values prompt comprehensive inspections or even replacement of the arc extinguishing chamber; the quality grade judgment module simulates the fault current multiple times, analyzes the quality gap coefficient to obtain the trend degree, the mean and the extreme value of the quality difference coefficient, and then calculates the quality grade coefficient for quality rating; this can not only evaluate the current quality, but also predict the quality change trend, discover potential problems in advance, provide a strong basis for preventive maintenance, and ensure the stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further details, features and advantages of the present application are disclosed in the following description of exemplary embodiments in conjunction with the accompanying drawings, in which: Figure 1 is a flow chart of the present invention; DETAILED DESCRIPTION

[0020] Several embodiments of the present application will be described in more detail below with reference to the accompanying drawings so that those skilled in the art can implement the present application. The present application can be embodied in many different forms and for many different purposes and should not be limited to the embodiments described herein. These embodiments are provided to make the present application comprehensive and complete and to fully convey the scope of the present application to those skilled in the art. The embodiments do not limit the present application.

[0021] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant art and / or the context of this specification, and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0022] See also Figure 1 As shown, the present invention provides a technical solution: A quality assessment system for an arc fault circuit breaker, comprising: Arc extinguishing chamber evaluation module: collects relevant information of the arc extinguishing chamber, and obtains the arc extinguishing chamber evaluation index after analysis and processing; The arc extinguishing chamber evaluation index acquisition includes the following parts: Collecting relevant information of the arc extinguishing chamber including the image information of the arc extinguishing chamber shell and relevant information of the arc extinguishing medium; The defect span value is obtained by analyzing the image information of the arc extinguishing chamber shell; The medium imbalance value is obtained by analyzing the information related to the arc extinguishing medium; The arc extinguishing chamber evaluation index is obtained by comprehensively processing the defect crossing value and the dielectric imbalance value; The defect span value can be obtained by: Dividing the outer shell of the arc extinguishing chamber into sub-regions according to the set area, and obtaining image information of each sub-region of the outer shell of the arc extinguishing chamber; Extracting features related to cracks and damage from the image information in each sub-region and marking the extracted features as crack regions and damage regions in each sub-region of the arc extinguishing chamber shell; performing pixel count on the marked crack regions and damage regions in each sub-region of the circuit breaker, and calculating the number of pixels in the crack regions and damage regions in each sub-region of the arc extinguishing chamber shell; Based on the resolution of the image, the number of pixels of the crack area and the damaged area in each sub-area of the arc extinguishing chamber shell is converted into the actual area to obtain the crack area and damaged area in each sub-area of the circuit breaker; Arrange the crack area and damage area in each sub-region in descending order; and extract the maximum crack area, minimum crack area, maximum damage area, and minimum damage area; Determine the locations of the regions corresponding to the maximum crack area, the minimum crack area, the maximum damage area, and the minimum damage area; Connect the centers of the regions corresponding to the maximum crack area and the minimum crack area with a straight line, and obtain the length of the straight line and record it as the crack span; Connect the centers of the areas corresponding to the maximum and minimum damaged areas with a straight line, and obtain the length of the straight line as the damage span; The defect span value is obtained by weighting the crack span and damage span.

[0023] Preset the weight factors of crack span and damage span, and calculate the product of crack span and damage span with their corresponding weight factors and then sum them to obtain the defect span value; The defect span value combines the information of crack span and damage span, and directly reflects the spatial distribution range of cracks and damage on the arc extinguishing chamber shell. A larger defect span value means that the cracks and damage are more widely distributed, possibly involving multiple key locations, posing a greater threat to the stability and sealing of the overall structure of the arc extinguishing chamber. For example, if the defect span of an arc extinguishing chamber is 30 cm, it means that the distance from the largest crack area to the smallest crack area and the distance from the largest damage area to the smallest damage area on the shell is large, and the defect distribution is relatively scattered. It may be necessary to inspect and repair a larger area of the shell. When the defect span reaches a certain value, such as 40 cm, it may mean that the cracks and damage in the arc extinguishing chamber shell have affected the sealing and insulation performance of the internal arc extinguishing medium. During the opening and closing process of the circuit breaker, it is easy to cause arc failure to be extinguished in time and insulation breakdown, which will endanger the safe operation of the power system. Maintenance personnel can formulate maintenance strategies based on the fault span value. A smaller fault span value may indicate a relatively localized problem, allowing for targeted repair measures. However, a larger fault span value may require a more comprehensive maintenance plan, even replacing the entire arc extinguishing chamber. For example, if the defect span is 15 cm and the cracks and damage are mainly concentrated in a local area, maintenance personnel can focus on repairing that area, such as using repair welding or filling with insulating materials. However, if the defect span reaches 50 cm and is more dispersed, it may be necessary to consider replacing the entire arc extinguishing chamber to ensure the performance and safety of the circuit breaker. Methods for obtaining medium imbalance values include: The pressure of the arc extinguishing medium is obtained through a pressure gauge at preset time intervals, and the arc extinguishing medium pressure at each time point is compared with the corresponding time point according to the time series, with time as the horizontal axis and pressure as the vertical axis to create a time-pressure line graph; Obtain the angle between the straight line between adjacent arc extinguishing medium pressure value points and the horizontal line. If the angle is acute, it is recorded as a descending slope; if the angle is obtuse, it is recorded as an ascending slope. Obtain all rising slopes and falling slopes, and sum up all falling slopes and rising slopes respectively to obtain the total falling slope and the total rising slope; Divide the total descending slope by the total ascending slope to obtain the leakage degree; A preset number of detection points are arranged around the arc extinguishing chamber, and leakage of the arc extinguishing medium is detected by a gas leak detector; Inspection points include the arc extinguishing chamber seal of the circuit breaker, pipeline interfaces, etc. Obtain the gas composition and content detected at each detection point at each time point, compare the gas composition with the arc extinguishing medium, and record the matching gas as the leakage medium; The concentration of the leaked medium detected at each detection point at the same time point is averaged to obtain the average leakage concentration; Multiply the mean leakage concentration by the number of detection points where the leaked medium was detected, and then multiply the result by the time between the first and last detection points to obtain the leakage value. The medium imbalance value is obtained by comprehensively analyzing the leakage degree and leakage value; After normalizing the leakage degree and leakage amount, the leakage degree and leakage amount are used as the major and minor axes of the ellipse, respectively, to establish an ellipse model, and the area of the ellipse model is calculated and recorded as the medium imbalance value; Fault current simulation module: simulates fault current to test the fault response of the circuit breaker and obtain the response delay index; Specifically include: After determining the signal characteristics of the fault current, a simulation signal is generated to conduct a power-on test on the circuit breaker; Determining the fault current signal characteristics includes: Amplitude: The amplitude of the fault arc current is usually larger than the normal operating current; Generally speaking, it may be several times the rated current. For example, in some low-voltage power distribution systems, the fault arc current amplitude may reach about 2 to 10 times the rated current. The specific multiple needs to be determined according to the actual application scenario and the specifications of the circuit breaker. Rate of change: The rate of change of the fault arc current is high, and its rise time may be between a few milliseconds and tens of milliseconds; for example, the current may rise from the normal amplitude to the fault arc amplitude in 5 to 20 milliseconds; Frequency component: Fault arc current contains abundant high-frequency components, usually ranging from several kilohertz to tens of kilohertz. These high-frequency components are one of the important characteristics that distinguish it from normal power frequency current. Generate analog signals including: Use a signal generator: Select a signal generator with multiple waveform output capabilities, such as a function generator or arbitrary waveform generator; First, set the signal generator's basic output waveform to a sine wave with a frequency equal to the power system's operating frequency (e.g., 50 Hz or 60 Hz) and an amplitude close to, but less than, the circuit breaker's rated current to simulate normal operating current. Then, through programming or manual setting, superimpose a pulse signal with a specific rise time and amplitude on the sine wave to simulate a sudden increase in fault arc current. The pulse's rise time and amplitude should be set based on the previously determined fault arc current characteristics. For example, set the pulse to rise from 0 to 5 times the rated current within 10 milliseconds; Adding high-frequency components: To more accurately simulate the arc fault current, a high-frequency component needs to be added to the signal. The modulation function of the signal generator can be used to modulate a high-frequency signal on the low-frequency analog current signal. The frequency of the high-frequency signal can be selected between several kilohertz and tens of kilohertz, such as 5kHz or 10kHz. The amplitude is adjusted according to the actual situation, generally a certain proportion of the low-frequency signal amplitude, such as 10% to 30%, to simulate the high-frequency component in the arc fault current. Afterwards, a power amplifier is used to amplify the analog current signal so that it has sufficient power to drive the load and circuit breaker in the test circuit; The selection of a power amplifier should be determined based on the required output power and signal frequency range to ensure that it can accurately amplify the analog signal without causing significant distortion; Use high-precision current measurement equipment, such as a current transformer with a digital oscilloscope or a high-precision ammeter, to calibrate the analog current signal. Measure the current signal's amplitude, rise time, frequency content, and other parameters to ensure they match the previously determined fault arc current characteristics. The time point when the circuit breaker is powered on is marked as the first time point, and the time point when the contact responds after the first time point is marked as the second time point; The time point at which the tripping mechanism controls the contact system of the circuit breaker to separate from the locking device after the second time point is marked as a third time point; Obtain the time difference between the first time point and the second time point, and record it as the previous time difference; The time difference between the first time point and the third time point is recorded as the total time difference; The time difference between the second time point and the third time point is recorded as the subsequent time difference; Substitute the previous time difference, total time difference, and next time difference into the formula to calculate the response delay index; Mark the previous time difference, total time difference, and last time difference as 、 、 The subsequent entry formula: ;Get the response delay index; in 、 、 are the maximum detection response time, reference power-off time, and contact and tripping delay time respectively; a1, a2, and a3 are the weight factors corresponding to the previous time difference, the total time difference, and the next time difference respectively; Testing module: The arc extinguishing chamber evaluation index and response delay index obtained after the circuit breaker response action test are combined with the temperature qualification index of the electromagnetic component to obtain the quality gap coefficient; The temperature qualification index of electromagnetic components includes: Using infrared thermal imaging detection equipment, obtain the temperature of the electromagnetic component before the first time point, which is recorded as the initial temperature; Obtain the temperature of the electromagnetic element at the third time point, which is recorded as the late temperature; Subtract the initial temperature from the later temperature to get the temperature difference; Preset the temperature difference allowable range, match the temperature difference with the temperature difference allowable range, and record the temperature difference within the temperature difference allowable range as a positive temperature difference; The temperature difference is divided by the total time difference to obtain the heating rate; an allowable range of the heating rate is preset, and the heating rate within the allowable range is recorded as the normal heating rate; The temperature qualification index is obtained by weighted calculation of the positive temperature difference and the normal heating rate; Preset weight factors for the positive temperature difference and the normal heating rate, multiply the positive temperature difference and the normal heating rate with their corresponding weight factors, and sum them to obtain a temperature qualification index; The process of obtaining the mass gap coefficient includes: After normalizing the arc extinguishing chamber evaluation index, response delay index, and temperature qualified index, a three-dimensional rectangle is constructed using the arc extinguishing chamber evaluation index, response delay index, and temperature qualified index as length, width, and height, respectively; Connect the centers of the bottom and top of the solid rectangle with a straight line, determine the center of the straight line and use it as the center of the circle, construct a sphere with half the temperature qualification index as the radius, cut the solid rectangle, and calculate the volume of the remaining part of the solid rectangle as the mass gap coefficient; Quality grade judgment module: Analyzes the quality gap coefficient obtained after simulating the fault current to obtain the quality grade coefficient, and rates the circuit breaker quality based on the quality grade coefficient; Preset the number of simulated fault currents and obtain the quality gap coefficient after each simulated fault current; Draw a line graph with the number of simulated fault currents as the horizontal axis and the quality gap coefficient as the vertical axis, and mark the points corresponding to each quality gap coefficient on the line graph; analyze the quality gap coefficient on the line graph to obtain the trend degree; After each simulated fault current, professionals will check the circuit breaker and adjust it to normal status, waiting for the next simulation test; The process of analyzing and obtaining trend degree includes: Obtain the angle between the adjacent mass gap coefficients and the horizontal line. If the angle is acute, it is recorded as a descending slope; if the angle is obtuse, it is recorded as an ascending slope. The ascending slope is recorded as a positive value, and the descending slope is recorded as a negative value. Sum up all the slopes to get the total slope value; The circuit breaker will inevitably wear out after multiple operations. Therefore, after multiple simulation tests, its quality gap coefficient will inevitably show an upward trend. Therefore, after summing up all the slopes (summing up the positive values corresponding to the rising slope and the negative values corresponding to the falling slope), the result will also be a positive value. The total value of the rise is calculated by summing up all the rising slopes; Divide the total slope value by the total rise value to get the trend degree; The average of the quality difference coefficients is calculated by averaging the obtained quality difference coefficients; The quality gap coefficient obtained after the last fault current simulation is extracted, and the difference between it and the quality gap coefficient obtained after the first fault current simulation is calculated to obtain the extreme value of the quality gap coefficient; The quality grade coefficient is obtained by comprehensively analyzing the trend degree, the mean value of the quality difference coefficient and the extreme value of the quality difference coefficient; Preset weight factors for trend degree, mean value of quality difference coefficient, and extreme value of quality difference coefficient, and calculate the product of trend degree, mean value of quality difference coefficient, extreme value of quality difference coefficient and their corresponding weight factors and then sum them to obtain the quality grade coefficient; The quality of circuit breakers is rated according to the quality grade coefficient: Three groups of threshold value ranges are preset, each group of threshold value ranges corresponds to a quality level, and the quality level coefficient is matched with the three groups of threshold value ranges to obtain the quality level corresponding to the quality level coefficient; the quality levels include qualified, defective, and unqualified.

[0024] The above formulas are obtained by collecting a large amount of data and performing software simulation, and a formula close to the actual value is selected. The influencing weight factors and specific coefficient values in the formula are set by technical personnel in this field according to actual conditions, and can be adjusted and modified later.

[0025] The above description of the embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A quality assessment system for arc fault circuit breaker, characterized in that: include: Arc extinguishing chamber evaluation module: collects relevant information of the arc extinguishing chamber, and obtains the arc extinguishing chamber evaluation index after analysis and processing; Fault current simulation module: simulates fault current to test the fault response of the circuit breaker and obtain the response delay index; Testing module: The arc extinguishing chamber evaluation index and response delay index obtained after the circuit breaker response action test are combined with the temperature qualification index of the electromagnetic component to obtain the quality gap coefficient; Quality grade judgment module: Analyze the quality gap coefficient obtained after simulating the fault current to obtain the quality grade coefficient, and perform quality rating on the circuit breaker based on the quality grade coefficient.

2. The arc fault circuit breaker quality assessment system according to claim 1, characterized in that: The arc extinguishing chamber evaluation index acquisition includes the following parts: Collecting relevant information of the arc extinguishing chamber including the image information of the arc extinguishing chamber shell and relevant information of the arc extinguishing medium; The defect span value is obtained by analyzing the image information of the arc extinguishing chamber shell; The medium imbalance value is obtained by analyzing the information related to the arc extinguishing medium; The arc extinguishing chamber evaluation index is obtained by comprehensively processing the defect crossing value and the dielectric imbalance value.

3. The arc fault circuit breaker quality assessment system according to claim 2, characterized in that: The defect span value can be obtained by: Dividing the outer shell of the arc extinguishing chamber into sub-regions according to the set area, and obtaining image information of each sub-region of the outer shell of the arc extinguishing chamber; Extracting features related to cracks and damage from the image information in each sub-region and marking the extracted features as crack regions and damage regions in each sub-region of the arc extinguishing chamber shell; performing pixel count on the marked crack regions and damage regions in each sub-region of the circuit breaker, and calculating the number of pixels in the crack regions and damage regions in each sub-region of the arc extinguishing chamber shell; Based on the resolution of the image, the number of pixels of the crack area and the damaged area in each sub-area of the arc extinguishing chamber shell is converted into the actual area to obtain the crack area and damaged area in each sub-area of the circuit breaker; Arrange the crack area and damage area in each sub-region in descending order; and extract the maximum crack area, minimum crack area, maximum damage area, and minimum damage area; Determine the locations of the regions corresponding to the maximum crack area, the minimum crack area, the maximum damage area, and the minimum damage area; Connect the centers of the regions corresponding to the maximum crack area and the minimum crack area with a straight line, and obtain the length of the straight line and record it as the crack span; Connect the centers of the areas corresponding to the maximum and minimum damaged areas with a straight line, and obtain the length of the straight line as the damage span; The defect span value is obtained by weighting the crack span and damage span.

4. The arc fault circuit breaker quality assessment system according to claim 2, characterized in that: Methods for obtaining medium imbalance values include: The pressure of the arc extinguishing medium is obtained at preset time intervals, and the arc extinguishing medium pressure at each time point is compared with the corresponding time point according to the time series, with time as the horizontal axis and pressure as the vertical axis to establish a time-pressure line graph; Obtain the angle between the straight line between adjacent arc extinguishing medium pressure value points and the horizontal line. If the angle is acute, it is recorded as a descending slope; if the angle is obtuse, it is recorded as an ascending slope. Obtain all rising slopes and falling slopes, and sum up all falling slopes and rising slopes respectively to obtain the total falling slope and the total rising slope; Divide the total descending slope by the total ascending slope to obtain the leakage degree; Arrange a preset number of detection points around the arc extinguishing chamber, obtain the gas composition and content detected at each detection point at each time point, compare the gas composition with the arc extinguishing medium, and record the matching gas as the leakage medium; The concentration of the leaked medium detected at each detection point at the same time point is averaged to obtain the average leakage concentration; Multiply the mean leakage concentration by the number of detection points where the leaked medium was detected, and then multiply the result by the time between the first and last detection points to obtain the leakage value. The medium imbalance value is obtained by comprehensively analyzing the leakage degree and leakage amount values.

5. The arc fault circuit breaker quality assessment system according to claim 1, characterized in that: The method of simulating a fault current to test the fault response of the circuit breaker and obtaining a response delay index specifically includes: After determining the signal characteristics of the fault current, a simulation signal is generated to conduct a power-on test on the circuit breaker; The time point when the circuit breaker is powered on is marked as the first time point, and the time point when the contact responds after the first time point is marked as the second time point; The time point at which the tripping mechanism controls the contact system of the circuit breaker to separate from the locking device after the second time point is marked as a third time point; Obtain the time difference between the first time point and the second time point, and record it as the previous time difference; The time difference between the first time point and the third time point is recorded as the total time difference; The time difference between the second time point and the third time point is recorded as the subsequent time difference; Substitute the previous time difference, the total time difference, and the next time difference into the formula to calculate the response delay index.

6. The arc fault circuit breaker quality assessment system according to claim 5, characterized in that: The temperature qualification index of electromagnetic components includes: Obtain the temperature of the electromagnetic element before the first time point, and record it as the initial temperature; Obtain the temperature of the electromagnetic element at the third time point, which is recorded as the late temperature; Subtract the initial temperature from the later temperature to get the temperature difference; Preset the temperature difference allowable range, match the temperature difference with the temperature difference allowable range, and record the temperature difference within the temperature difference allowable range as a positive temperature difference; The temperature difference is divided by the total time difference to obtain the heating rate; an allowable range of the heating rate is preset, and the heating rate within the allowable range is recorded as the normal heating rate; The temperature qualification index is obtained by weighted calculation of the positive temperature difference and the normal heating rate.

7. The arc fault circuit breaker quality assessment system according to claim 6, characterized in that: The process of obtaining the mass gap coefficient includes: After normalizing the arc extinguishing chamber evaluation index, response delay index, and temperature qualified index, a three-dimensional rectangle is constructed using the arc extinguishing chamber evaluation index, response delay index, and temperature qualified index as length, width, and height, respectively; Connect the centers of the bottom and top of the three-dimensional rectangle with a straight line, determine the center of the straight line and use it as the center of the circle, construct a sphere with half the temperature qualification index as the radius, cut the three-dimensional rectangle, and calculate the volume of the remaining part of the three-dimensional rectangle as the mass gap coefficient.

8. The arc fault circuit breaker quality assessment system according to claim 7, characterized in that: The quality gap coefficient obtained after simulating the fault current is analyzed to obtain the quality grade coefficient: Preset the number of simulated fault currents and obtain the quality gap coefficient after each simulated fault current; Draw a line graph with the number of simulated fault currents as the horizontal axis and the quality gap coefficient as the vertical axis, and mark the points corresponding to each quality gap coefficient on the line graph; analyze the quality gap coefficient on the line graph to obtain the trend degree; The average of the quality difference coefficients is calculated by averaging the obtained quality difference coefficients; The quality gap coefficient obtained after the last fault current simulation is extracted, and the difference between it and the quality gap coefficient obtained after the first fault current simulation is calculated to obtain the extreme value of the quality gap coefficient; The quality grade coefficient is obtained by comprehensively analyzing the trend degree, the mean value of the quality difference coefficient and the extreme value of the quality difference coefficient.

9. The arc fault circuit breaker quality assessment system according to claim 8, characterized in that: The quality of circuit breakers is rated according to the quality grade coefficient: Three groups of threshold value ranges are preset, each group of threshold value ranges corresponds to a quality level, and the quality level coefficient is matched with the three groups of threshold value ranges to obtain the quality level corresponding to the quality level coefficient; the quality levels include qualified, defective, and unqualified.

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