Switch cabinet circuit breaker opening and closing current detection method and system

Abstract

The invention relates to the field of electrical variable measurement, in particular to an opening and closing current detection method and system for a switch cabinet circuit breaker, and the method comprises the steps: increasing a sampling frequency T1 to a sampling frequency T2 when the average change amplitude of the current is greater than a preset threshold value F1, collecting the current again through T1 when the current collected through T2 and the current collected through T1 have the same change rule, if the current time is changed from the high-frequency time period to the low-frequency time period, changing F1 by utilizing the change rule similarity of the current in the low-frequency time period and the high-frequency time period obtained recently on the basis of a threshold F2, and if the current time is changed from the low-frequency time period to the high-frequency time period, changing F1; and the F2 is changed by using the similarity b of the change rules of the current in the low-frequency time period and the high-frequency time period obtained in the last two times, and opening and closing parameters are read from all the collected opening and closing currents and detected. According to the invention, the current generated by transient switching-on and switching-off actions can be accurately captured from a large amount of interference current.

Description

Technical Field

[0001] The present invention relates to the field of electrical variable measurement, and in particular to a method and system for detecting the opening and closing current of a switch cabinet circuit breaker. Background Art

[0002] The core function of the circuit breaker is to realize the opening and closing operation and realize the load allocation. During the operation of the equipment, the circuit breaker will fail and need repair and maintenance. The failures include rust, jamming, loose parts, short circuit between coil turns, etc. These failures will cause abnormal opening and closing of the switch equipment, or even serious accidents such as refusal to open or close. The opening and closing action current of the circuit breaker is an important basis for judging whether there is a fault and whether timely repair and maintenance is needed. Therefore, the detection of the opening and closing current of the circuit breaker has always been an important part of circuit breaker detection and maintenance.

[0003] The existing current detection method is to use a current sensor to collect the opening and closing current. However, since the opening and closing action time of the circuit breaker is relatively short, generally in tens of milliseconds, and due to the interference of the external electromagnetic environment and the internal circuit interference of the detection device, these interferences lead to missampling (that is, when the circuit breaker is not opening and closing, it is mistakenly believed that the circuit breaker has an opening and closing action due to interference) or miss the collection of important current data (for example, miss the collection of current at the start and end time points of the opening and closing action), which makes it difficult to accurately capture the current generated by the short opening and closing action from a large amount of interfering current, and thus makes the opening and closing current detection result of the circuit breaker unreliable. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method and system for detecting the opening and closing current of a switch cabinet circuit breaker.

[0005] A method and system for detecting the opening and closing current of a switch cabinet circuit breaker of the present invention adopts the following technical solutions: An embodiment of the present invention provides a method for detecting the opening and closing current of a switch cabinet circuit breaker, the method comprising the following steps: The opening and closing current is collected at a preset frequency T1. When the average change amplitude of the current is greater than the preset threshold F1, T1 is increased to a preset frequency T2 and the current is continuously collected. When the current collected at T2 has the same change pattern as the current collected at T1, the current is collected again at T1. When the current has different change patterns, the current is continuously collected at T2. The period of time when current is collected at T1 is recorded as the low-frequency period, and the period of time when current is collected at T2 is recorded as the high-frequency period; If the current moment changes from the high-frequency period to the low-frequency period, F1 is changed by using the similarity of the change rules of the current in the most recently obtained low-frequency period and the most recently obtained high-frequency period, including: when the similarity of the change rule is greater than a preset threshold value F2, the changed F1 is positively correlated with the maximum change amplitude of the current in the most recently obtained high-frequency period; when the similarity of the change rule is less than or equal to the preset threshold value F2, the changed F1 is positively correlated with the minimum change amplitude of the current in the most recently obtained high-frequency period; If the current moment changes from a low-frequency period to a high-frequency period, F2 is changed using the similarity b of the current change rules in the two most recent low-frequency periods and the most recent high-frequency period, and the changed F2 is negatively correlated with b; The opening and closing parameters are read out from all the collected opening and closing currents and tested.

[0006] Preferably, the method for determining whether the current collected at T2 has the same change rule as the current collected at T1 is: Record the current sequence collected at the frequency T2 as the second current sequence, record the current sequence collected at the frequency T1 before the frequency is increased to T2 as the first current sequence, and obtain the current difference between the first current sequence and the second current sequence; In the second current sequence, starting from the first current data, a current data is taken out after every other current and forms a sequence L(1), and the current difference between the first current sequence and L(1) is obtained; In the second current sequence, starting from the first current data, a current data is taken out after every two currents to form a sequence L(2), and the current difference between the first current sequence and L(2) is obtained; Similarly, in the second current sequence, starting from the first current data, a current data is taken out after every N1 currents to form a sequence L(N1), and the current difference between the first current sequence and L(N1) is obtained; N1 is a preset value.

[0007] When the mean of all current differences obtained is less than the preset threshold th1, it is determined that the first current sequence and the second current sequence have the same variation law; when the mean of all current differences obtained is greater than or equal to the preset threshold th1, it is determined that the first current sequence and the second current sequence do not have the same variation law.

[0008] Preferably, the specific steps for obtaining the similarity of the changing rules of the current in the most recently obtained low-frequency period and the most recently obtained high-frequency period are as follows: For the current sequence List1 formed by the current in the most recent low-frequency period, and the current sequence List2 formed by the current in the most recent high-frequency period, the current difference between List1 and List2 is recorded as x, exp(-x) is used as the similarity of the change law, and exp() represents an exponential function with a natural constant as the base.

[0009] Preferably, the specific steps for obtaining the most recently obtained maximum change amplitude of the current in the high-frequency period and the most recently obtained minimum change amplitude of the current in the high-frequency period are as follows: For the current sequence List2 formed by the current in the most recently obtained high-frequency time period, the difference between every two adjacent current data in List2 is calculated; the differences of all adjacent current data in List2 are clustered into several categories, and the mean of all differences in each category is calculated. For the category with the largest mean of all differences, the mean of all differences in the category with the largest mean is used as the maximum change amplitude; for the category with the smallest mean of all differences, the mean of all differences in the category with the smallest mean is used as the minimum change amplitude.

[0010] Preferably, when the similarity of the change rule is greater than a preset threshold value F2, the changed F1 is positively correlated with the maximum change amplitude of the current in the most recent high-frequency period; when the similarity of the change rule is less than or equal to the preset threshold value F2, the changed F1 is positively correlated with the minimum change amplitude of the current in the most recent high-frequency period, including the specific formula as follows: When the similarity of the change rule is greater than the preset threshold value F2, w×f1+(1-w)×F1 is used as the changed F1; when the similarity of the change rule is less than or equal to the preset threshold value F2, w×F1+(1-w)×f2 is used as the changed F1; Among them, w represents the similarity of the change pattern; f1 and f2 represent the maximum and minimum change amplitudes.

[0011] Preferably, the specific steps for obtaining the similarity b of the current change rules in the two most recently obtained low-frequency periods and the most recently obtained high-frequency period are as follows: The currents obtained in the two most recent low-frequency periods are arranged in chronological order to obtain a sequence List3, and the currents obtained in the most recent high-frequency period constitute a sequence List2. The similarity of the changing rules between List3 and List2 is recorded as b.

[0012] Preferably, the method of changing F2 by using the similarity b of the current variation law in the two most recently obtained low-frequency periods and the most recently obtained high-frequency period includes the following specific formula: The changed F2 is F2×(yb), where y represents a preset offset coefficient.

[0013] Preferably, the step of reading the opening and closing parameters from all the collected opening and closing currents and performing detection includes the following specific steps: The start time point and the end time point of the opening and closing action are read out from all the collected opening and closing currents; the time difference between the end time point and the start time point is used as the opening and closing parameter, and the absolute value of the difference between the obtained opening and closing parameters and the opening and closing parameters measured when the circuit breaker leaves the factory is calculated. The ratio of the absolute value to the opening and closing parameters measured when the circuit breaker leaves the factory is recorded as the parameter abnormality degree. When the parameter abnormality degree is greater than the preset threshold value th2, the circuit breaker detection result is determined to be abnormal.

[0014] Preferably, the specific steps of obtaining the current difference are as follows: Linear normalization is performed on any two current sequences respectively, and the DTW distance between any two current sequences after linear normalization is recorded as the current difference.

[0015] Another embodiment of the present invention provides a switch cabinet circuit breaker opening and closing current detection system, the system includes a detection device and a display, the detection device includes an opening current sensor and a closing current sensor for collecting opening and closing currents, and the display is used to display the opening and closing currents; the detection device also includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the steps of the above-mentioned switch cabinet circuit breaker opening and closing current detection method are implemented.

[0016] The beneficial effects of the technical solution of the present invention are: The present invention collects the opening and closing current at a preset frequency T1. When the average change amplitude of the current is greater than the preset threshold F1, T1 is increased to a preset frequency T2 and the current is continuously collected. When the current collected at T2 has the same change rule as the current collected at T1, the current is collected again at T1. When there are different change rules, the current is continuously collected at T2. When the current generated during the opening and closing action is short-lived, the high-frequency sampling and low-frequency sampling are alternately sampled to avoid obtaining a large amount of current data with interference but invalid for the opening and closing current detection when continuously sampling the current data at a high speed, or in other words, the current generated by the opening and closing action that exists for a short time can be captured in a timely manner among a large amount of invalid currents to a certain extent.

[0017] On this basis, when the high-frequency period changes to the low-frequency period, the present invention uses the similarity of the change rules of the current in the most recently obtained low-frequency period and the most recently obtained high-frequency period to change F1. The specific adjustment method is that when the similarity of the change rule is greater than the preset threshold F2, the changed F1 is positively correlated with the maximum change amplitude of the current in the most recently obtained high-frequency period; when the similarity of the change rule is less than or equal to the preset threshold F2, the changed F1 is positively correlated with the minimum change amplitude of the current in the most recently obtained high-frequency period. This process continuously and dynamically changes the preset threshold F1 to dynamically control the timing of switching to the high-frequency period again when in the low-frequency period, so that it is suitable for the interference existing in the collected current, further avoiding the problem of missing the start and end time points of the opening and closing action or the problem of mis-sampling during low-frequency sampling (that is, when the circuit breaker does not have an opening and closing operation, it is mistakenly believed that the circuit breaker has an opening and closing operation due to interference), and further ensuring that the current generated by the short-term opening and closing action can be captured from a large number of interfering currents.

[0018] Furthermore, if the current moment changes from a low-frequency period to a high-frequency period, the similarity b of the current change rules in the two most recently obtained low-frequency periods and the most recently obtained high-frequency period is changed to F2, and the changed F2 is negatively correlated with b. In this process, by dynamically adjusting F2, F2 approaches or stabilizes at a better value in real time with the sampling process. The better value refers to whether to determine the timing of changing from a low-frequency period to a high-frequency period with a larger current change amplitude (that is, the maximum change amplitude) or a smaller current change amplitude (that is, the minimum change amplitude) according to the interference of the current, so as to further avoid the situation of collecting a large amount of invalid current at high speed and high frequency.

[0019] In summary, this embodiment dynamically and alternately changes F1 and F2 through the current changes when switching from the high-frequency period to the low-frequency period and then from the low-frequency period to the high-frequency period, thereby avoiding the problem of collecting a large amount of invalid interference current at high speed and high frequency, and avoiding the problem of missing the start and end time points of the opening and closing action during low-frequency sampling, further ensuring that the current generated by the short-term opening and closing action can be accurately captured from a large amount of interfering current, thereby ensuring the reliability of the current detection result. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1A flow chart of the steps of a method for detecting the opening and closing current of a switch cabinet circuit breaker provided by one embodiment of the present invention; Figure 2 A schematic diagram of a high frequency period and a low frequency period when the threshold F1 is not changed in an embodiment of the present invention; Figure 3 It is a schematic diagram of the high-frequency period and the low-frequency period after the threshold F1 is changed in one embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the opening and closing current detection method and system of a switch cabinet circuit breaker proposed by the present invention, its specific implementation method, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0023] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0024] The specific scheme of the method and system for detecting the opening and closing current of a switch cabinet circuit breaker provided by the present invention is described in detail below with reference to the accompanying drawings.

[0025] Embodiment 1: The present embodiment provides a switch cabinet circuit breaker opening and closing current detection system, the system includes at least one detection device and a display; the detection device is used to collect the opening and closing current (opening current and closing current) of the circuit breaker, and the display is used to display the opening and closing current of the circuit breaker.

[0026] The detection device includes an opening current sensor and a closing current sensor; the opening current sensor adopts an open-and-close design and can be directly clamped on the opening power line of the circuit breaker, which is easy to install; the opening current sensor is designed according to the characteristics of the circuit breaker opening operation power line and can be easily clamped on the circuit breaker opening operation power line; the opening diameter of the opening current sensor is not less than 20mm.

[0027] The detection device also includes a detection host, and the opening current sensor is connected to the detection host through a cable; the opening current sensor cable includes a power line and a signal line; the opening current sensor is powered by the detection host through the power line in the opening current sensor cable; the output signal of the opening current sensor is current, which is uploaded to the opening current detection interface of the detection host through the signal line in the opening current sensor cable.

[0028] The closing current sensor and the opening current sensor usually use the same type of current sensor.

[0029] The interface between the closing current sensor and the detection host is the closing current detection interface, and the rest is the same as the opening current sensor.

[0030] The inside of the detection host includes the amplifier circuit, AD circuit, and power module.

[0031] The function of the amplifier circuit is to amplify the output current signal of the opening current sensor and the closing current sensor, because the output current of the current sensor is very weak, usually 4~20mA, and the signal is too weak, which easily leads to sampling deviation, so it needs to be amplified. The amplifier circuit is implemented by an operational amplifier.

[0032] The function of the AD circuit is to sample the analog current signal and convert it into a digital signal.

[0033] The function of the power module is to supply power to the detection host and the equipment connected to the detection host (opening current sensor, closing current sensor, etc.). The power module adopts a wide input power conversion module, which is compatible with AC85~270V; DC100~380V; the power conversion module converts the input power to the power required by the test equipment: ±5V, 12V, 24V.

[0034] The detection host also includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, a method for detecting the opening and closing currents of a switch cabinet circuit breaker is implemented, which is used to collect the opening and closing currents (i.e., the opening current and the closing current) and perform detection.

[0035] Embodiment 2: like Figure 1 As shown, this embodiment provides a method for detecting the opening and closing current of a switch cabinet circuit breaker, the method comprising: Step S201, collecting the opening and closing current at a preset frequency T1, and when the average change amplitude of the current is greater than the preset threshold F1, increasing T1 to the preset frequency T2 and continuing to collect the current.

[0036] When collecting the opening and closing current (opening current or closing current), considering that the opening and closing time (opening time or closing time) is relatively short, generally tens of milliseconds, for example, the factory parameters of the circuit breaker in this embodiment are marked as: opening time 39.20 milliseconds, closing time 69.70 milliseconds. Therefore, in order to capture the opening and closing current in the short opening and closing time, the current sensor is required to sample the current at a high speed.

[0037] However, since the specific execution time of the opening and closing action cannot be determined, the current sampled by the opening and closing current sensor is not necessarily the current during the execution of the opening and closing action, but includes the current before and after the action is executed.

[0038] It should be noted that, in this embodiment, there is a delay between when the staff sends out the opening and closing signal command and when the circuit breaker performs the opening and closing action, such as the time taken by the signal command transmission, the time taken by the mechanical parts of the circuit breaker to perform the action, and even the staff's reaction time, all of which lead to the existence of a delay, and this delay is roughly between 1 second (equal to 1000 milliseconds) and 4 seconds (equal to 4000 milliseconds). Compared with the short opening and closing time, it is impossible for the circuit breaker to connect the opening and closing current sensor to the current screen at the moment of performing the opening and closing action, resulting in most of the collected current being invalid. Therefore, the general practice is to connect the opening and closing current sensor to the current screen in advance, and then collect the current in real time, and then extract the opening and closing current of the circuit breaker during the opening and closing action from all the collected opening and closing currents. This current is the current to be obtained in this embodiment and used to detect the circuit breaker.

[0039] Since all the collected opening and closing currents contain a large amount of useless currents, that is, the currents are still being collected at a high speed when the opening and closing actions have not yet been executed or have been completed, these currents are useless. On the one hand, these currents will interfere with the subsequent detection process, and on the other hand, they will take up too much data storage space or transmission time.

[0040] In this embodiment, in order to avoid collecting too much opening and closing current that interferes with the subsequent detection process, the opening and closing current is first collected at a preset frequency T1. When the average current change amplitude is greater than the preset threshold F1, T1 is increased to the preset frequency T2 and the current continues to be collected.

[0041] The above T1 is less than T2. ​​This embodiment takes T1=0.2 as an example for description, indicating that 0.2 currents are collected every millisecond, that is, one current is sampled every 5 milliseconds; T2 is equal to 1 as an example for description, indicating that one current is collected every millisecond. If the average current change amplitude is greater than the preset threshold F1, it means that the current has changed significantly, indicating that a switch-on and switch-off action has occurred; on the contrary, when the average current change amplitude is not greater than the preset threshold F1, it means that the current has not changed significantly, indicating that no switch-on and switch-off action has occurred.

[0042] In summary, in the above process, when no opening and closing action occurs, less current is collected at a lower sampling frequency. When an opening and closing action occurs, the current is sampled at a high speed to obtain detailed changes in a large amount of current during the execution of the opening and closing action.

[0043] As an example, the method for obtaining the average current variation amplitude includes: When current is collected at a frequency of T1, the most recently collected N0 current data are acquired after each current is collected, and the difference between the maximum value and the minimum value of these currents is taken as the average current variation amplitude.

[0044] In other examples, the standard deviation of N0 current data is taken as the average current variation amplitude.

[0045] In some other examples, for N0 current data, the difference (ie, the absolute value of the difference) between every two adjacent current data is calculated, and the average of all the differences in the N0 current data is taken as the average current change amplitude.

[0046] In addition, this embodiment is described by taking N0=10 as an example. In other embodiments, N0 may be set to other values, which are not limited in this embodiment. It only needs that N0 is greater than or equal to 2.

[0047] In particular, when the most recently collected current data is less than N0 when collecting current at frequency T1, all currents collected after the current collection starts at frequency T1 are processed as above, and the average current change amplitude is obtained. If there is only one current collected after the current collection starts at frequency T1, the difference between the current and the current collected at the last moment is taken as the average current change amplitude. If there is no current collected at the last moment, the average current change amplitude is no longer calculated, but the current is continuously collected at frequency T1.

[0048] In some other embodiments, when the current data collected most recently is less than N0 when the current is collected at the frequency T1, the average current change amplitude is no longer calculated, but the current continues to be collected at the frequency T1.

[0049] In addition, this embodiment is described by taking F1 equal to 0.2A as an example (in this embodiment, the amplifier amplifies the output signal of the current sensor by 100 times). In other embodiments, F1 can be set to other values, which are not specifically limited in this embodiment.

[0050] Step S202: When the current collected at T2 has the same variation pattern as the current collected at T1, collect the current again at T1; when they have different variation patterns, continue to collect the current at T2; the period of collecting the current at T1 is recorded as the low-frequency period, and the period of collecting the current at T2 is recorded as the high-frequency period.

[0051] When the detection device uses the detection host and the current sensor to collect current, it is inevitable that there will be mis-sampling. Mis-sampling means that when the circuit breaker has no opening and closing operation, the detection host mistakenly thinks that the circuit breaker has opening and closing operation due to interference, thereby triggering mis-sampling (that is, the sampling frequency T1 is mistakenly increased to the preset frequency T2 in step S101). The interference includes internal interference and external interference. The external interference includes: electromagnetic interference from surrounding power equipment, even electromagnetic interference from high-voltage power equipment that is close, and interference from other power equipment coupled through power lines or ground lines. Internal interference includes thermal noise of electronic components inside the sensor, amplifier noise, AD current noise, etc., especially when the output circuit signal of the current sensor is too weak, the interference of these noises will be more obvious. Although these can be partially eliminated by adding a filtering circuit, there is still unavoidable interference of internal and external interference to weaker signals.

[0052] In this embodiment, when the average current change amplitude is greater than the preset threshold value F1 and T1 is increased to the preset frequency T2, the current sequence collected at the frequency T2 is recorded as the second current sequence, and the current sequence collected at the frequency T1 before the frequency is increased to T2 is recorded as the first current sequence. When the first current sequence and the second current sequence have the same change law, it means that there is no opening and closing action, and the current is collected again at the frequency T1. When the first current sequence and the second current sequence do not have the same change law, it means that the current collected by the high-speed and high-frequency has changed significantly, and the current continues to be collected at the frequency T2.

[0053] Then, continue to acquire the second current sequence collected at frequency T2, and the first current sequence collected at frequency T1 before the frequency increases to T2; similarly, when the first current sequence and the second current sequence have the same change pattern, it means that there is no opening and closing action, and the current is collected again at frequency T1. When the first current sequence and the second current sequence do not have the same change pattern, it means that the current collected by high speed and high frequency has changed significantly, and the current is collected at frequency T2.

[0054] And so on, the current is continuously collected.

[0055] In the above process, the period of current collection at frequency T1 is recorded as a low-frequency period, and the period of current collection at frequency T2 is recorded as a high-frequency period. In the whole process of current collection, low-frequency periods and high-frequency periods appear alternately, which can avoid the problem of mis-sampling caused by interference to a certain extent, and thus avoid excessive collection of invalid current data, which will interfere with the detection process.

[0056] As an optional example, a method for determining whether the first current sequence and the second current sequence have the same change rule includes: Whenever a current data is collected at T2, the obtained second current sequence and the first current sequence are linearly normalized respectively, and the DTW distance between the normalized second current sequence and the first current sequence is obtained, which is recorded as the current difference between the first current sequence and the second current sequence.

[0057] The DTW distance is obtained by using the DTW algorithm. The DTW algorithm is a well-known technology and will not be described in detail in this embodiment.

[0058] When the difference is smaller than the preset threshold th1, it is determined that the first current sequence and the second current sequence have the same variation rule; when the difference is greater than or equal to the preset threshold th1, it is determined that the first current sequence and the second current sequence do not have the same variation rule.

[0059] This embodiment is described by taking th1=0.63 as an example. In other embodiments, th1 may be set to other values, which are not specifically limited in this embodiment.

[0060] As a preferred example, a method for determining whether the first current sequence and the second current sequence have the same change rule includes: In the second current sequence, starting from the first current data, a current data is taken after every other current, and the sequence formed by these current data is recorded as L(1), and the difference between the first current sequence and L(1) is obtained.

[0061] Then, in the second current sequence, starting from the first current data, a current data is taken after every two currents, and the sequence formed by these current data is recorded as L(2), and the difference between the first current sequence and L(2) is obtained.

[0062] Similarly, in the second current sequence, starting from the first current data, a current data is taken after every N1 currents, and the sequence formed by these current data is recorded as L(N1), and the difference between the first current sequence and L(N1) is obtained.

[0063] The mean of all the differences obtained above is calculated. When the mean is less than the preset threshold th1, it is determined that the first current sequence and the second current sequence have the same variation law; when the mean is greater than or equal to the preset threshold th1, it is determined that the first current sequence and the second current sequence do not have the same variation law.

[0064] Compared with the above optional examples, this preferred example can more comprehensively and accurately evaluate the changing rules of the first current sequence and the second current sequence.

[0065] This embodiment is described by taking N1=5 as an example. In other embodiments, N1 may be set to other values, which are not specifically limited in this embodiment.

[0066] In particular, when the number of current data in the second current sequence is less than N2, it is no longer judged that they have the same change law, but the current continues to be collected at T2 to avoid the situation where there are too few current data in the second current sequence and the change law cannot be obtained. This implementation is described using N2=5 as an example. In other embodiments, N2 can be set to other values, which is not limited in this embodiment.

[0067] Step S203, if the current moment changes from a high-frequency period to a low-frequency period, F1 is changed using the similarity of the changing patterns of the currents in the most recently obtained low-frequency period and the most recently obtained high-frequency period, including: when the similarity of the changing patterns is greater than a preset threshold value F2, the changed F1 is positively correlated with the maximum changing amplitude of the current in the most recently obtained high-frequency period; when the similarity of the changing patterns is less than or equal to the preset threshold value F2, the changed F1 is positively correlated with the minimum changing amplitude of the current in the most recently obtained high-frequency period.

[0068] For the preset threshold F1 used in step S201 and step S202, if the preset threshold F1 is set too large, it will result in failure to timely capture the small current fluctuation changes that exist when the opening and closing actions are executed, resulting in the opening and closing actions not entering the high-speed sampling state when they have already started or have not yet ended (that is, high-speed sampling is still not performed with T2), resulting in the collected current not being able to clearly show the start time point and end time point of the opening and closing actions.

[0069] When the preset threshold F1 is set too small, there will be a slight interference to trigger high-speed sampling (that is, high-speed sampling at T2), increase the number of false sampling, introduce invalid current data with more interference, and affect the detection process (for example, affect the judgment of the start time and end time of the opening and closing action).

[0070] In this embodiment, when the current moment changes from a high-frequency period to a low-frequency period, F1 is changed by utilizing the similarity of the current change laws in the most recently obtained low-frequency period and the most recently obtained high-frequency period, thereby solving the problem of F1 being set too large or too small as described above, so that F1 can dynamically adapt to the sampling process, further ensuring that the influence of current interference on current collection is avoided in real time.

[0071] The process of changing F1 includes: when the similarity of the change law is greater than the preset threshold value F2, the changed F1 is positively correlated with the maximum change amplitude of the current in the most recent high-frequency period; when the similarity of the change law is greater than the preset threshold value F2, the changed F1 is positively correlated with the minimum change amplitude of the current in the most recent high-frequency period.

[0072] On the one hand, the similarity of the changing rules is greater than the preset threshold value F2, indicating that when the current moment changes from the high-frequency period to the low-frequency period, the current in the high-frequency period is more likely to be in the same state as the current in the previous low-frequency period, that is, the same interference state, and both are in the state where the opening and closing actions are not triggered; at the same time, considering that the current collected in the most recent high-frequency period can show the fluctuation changes of the current limiting under internal and external interference in more detail (lossless), therefore, when the similarity of the changing rules is large, the maximum change amplitude of the current in the most recent high-frequency period can be used to obtain the changed F1.

[0073] The larger the maximum change amplitude of the current in the most recent high-frequency period is, the larger the preset threshold F1 can be used to determine whether it is necessary to switch from the low-frequency period to the high-frequency period again for the upcoming low-frequency period, without worrying about missing (or failing to capture) the start and end time points of the opening and closing actions; conversely, the smaller the maximum change amplitude of the current in the most recent high-frequency period is, the smaller the preset threshold F1 can be used to determine whether it is necessary to switch from the low-frequency period to the high-frequency period for the upcoming low-frequency period, without worrying about missing (or failing to capture) the start and end time points of the opening and closing actions.

[0074] On the other hand, when the similarity of the change rule is not greater than the preset threshold F2, it means that when the current moment changes from the high-frequency period to the low-frequency period, the current in the high-frequency period is more likely to have changed compared to the current in the previous low-frequency period, such as changes in internal interference or external interference, or changes caused by the opening and closing action. When the similarity of the change rule is smaller, it is more necessary to use the minimum change amplitude of the current in the high-frequency period obtained recently to obtain the changed F1; the smaller the minimum change amplitude, the more it is necessary to use a smaller preset threshold F1 to judge whether it is necessary to switch from the low-frequency period to the high-frequency period again for the upcoming low-frequency period, so as to avoid missing the start time point and end time point of the upcoming opening and closing action; on the contrary, the larger the minimum change amplitude, the larger the preset threshold F1 can be used to judge whether it is necessary to switch from the low-frequency period to the high-frequency period again for the upcoming low-frequency period, so as to avoid missing the start time point and end time point of the upcoming opening and closing action.

[0075] For the change from high frequency period to low frequency period, F1 is changed by using the similarity of the current change rules in the most recently obtained low frequency period and the most recently obtained high frequency period, so that F1 can be based on the change of the current when deciding to change from low frequency period to high frequency period, avoiding the situation that the opening and closing action cannot be captured in time and at high speed when the high frequency period is changed to low frequency period according to the fixed F1 (or F1 that is too large or too small). For example, avoid switching to high frequency period after the opening and closing start time point has passed, and avoid switching to high frequency period early before the opening and closing start time point arrives.

[0076] Each subsequent time when the high-frequency period changes to the low-frequency period, the preset threshold F1 is dynamically changed using the above method.

[0077] As an illustration, Figure 2 The figure in the figure is a schematic diagram of a high-frequency period and a low-frequency period (current is collected every 5ms in the low-frequency period and every 1ms in the high-frequency period). The figure shows a section of the tripping current collected when the threshold F1 remains unchanged; Figure 3 The figure also shows a high-frequency period and a low-frequency period, which shows a section of the tripping current collected after the threshold F1 is dynamically changed. Points P1 and P3 represent the start time of the tripping action, and P2 and P4 represent the end time of the tripping action. Figure 2 The starting time point P3 is not accurate. Figure 3 The starting time point P1 in is relatively accurate ( Figure 3 The changed threshold F1 is 0.06A). That is, according to Figure 2 , Figure 3 As shown, when the threshold F1 cannot adapt to the interference changes in the current, the accurate start time is missed during low-frequency sampling, affecting the subsequent current inspection results.

[0078] As an example, the similarity of the changing rules of the current in the most recently obtained low-frequency period and the most recently obtained high-frequency period includes the following methods: For the current sequence List1 formed by the current in the most recent low-frequency period, and the current sequence List2 formed by the current in the most recent high-frequency period, the difference between List1 and List2 (calculation method minus step S202) is recorded as x, and exp(-x) is used as the similarity of the change law. exp() represents an exponential function with a natural constant as the base.

[0079] As another example, the similarity of the changing rules of the current in the most recently obtained low-frequency period and the most recently obtained high-frequency period includes the following methods: Perform linear interpolation on F1 to make List1 and List2 have the same length, and then use the Pearson correlation coefficient between List1 and List2 as the similarity of the change pattern. In particular, when the Pearson correlation coefficient is less than 0.1, the similarity of the change pattern is set to 0.1.

[0080] As an optional example, a method for obtaining the most recently obtained maximum change amplitude of the current in the high-frequency period and the most recently obtained minimum change amplitude of the current in the high-frequency period includes: For the current sequence List2 formed by the current in the most recently obtained high-frequency period, the difference (that is, the absolute value of the difference) is calculated for every two adjacent current data in List2. For the differences obtained for all adjacent current data in List2, the maximum value or minimum value of these differences is used as the maximum change amplitude and the minimum change amplitude, respectively.

[0081] As a preferred example, a method for obtaining the most recent maximum change amplitude of the current in the high-frequency period and the most recent minimum change amplitude of the current in the high-frequency period includes: In the above optional example, the maximum value or the minimum value of these differences is used as the maximum change amplitude and the minimum change amplitude respectively. This method cannot reflect the overall change of the current.

[0082] In this preferred example, these differences are clustered into several categories, for example, they are clustered into 3 categories using the K-Means clustering algorithm. Each category contains several differences, and the mean of all differences in each category is calculated. For the category with the largest mean of all differences, the mean of all differences in this category is used as the maximum change range; for the category with the smallest mean of all differences, the mean of all differences in this category is used as the minimum change range.

[0083] As an optional example, when the similarity of the change rule is greater than a preset threshold value F2, the changed F1 is positively correlated with the maximum change amplitude of the current in the most recent high-frequency period; when the similarity of the change rule is less than or equal to the preset threshold value F2, the changed F1 is positively correlated with the minimum change amplitude of the current in the most recent high-frequency period, including the method of: When the similarity of the change rule is greater than the preset threshold F2, the maximum change amplitude is used as the changed F1; when the similarity of the change rule is less than or equal to the preset threshold F2, the minimum change amplitude is used as the changed F1.

[0084] As a preferred example, when the similarity of the change rule is greater than the preset threshold value F2, the changed F1 is positively correlated with the maximum change amplitude of the current in the most recent high-frequency period; when the similarity of the change rule is less than or equal to the preset threshold value F2, the changed F1 is positively correlated with the minimum change amplitude of the current in the most recent high-frequency period, including the method of: When the similarity of the change rule is greater than the preset threshold value F2, w×f1+(1-w)×F1 is used as the changed F1. When the similarity of the change rule is less than or equal to the preset threshold value F2, w×F1+(1-w)×f2 is used as the changed F1.

[0085] Among them, w represents the similarity of the change pattern; f1 and f2 represent the maximum and minimum change amplitudes.

[0086] In this preferred example, the current F1 (which describes the adjusted threshold F1 when converting from a low-frequency period to a high-frequency period in history) is integrated with the maximum change amplitude (or the minimum change amplitude) to determine the timing of the next transition from a low-frequency period to a high-frequency period (that is, the size of the changed F1), which is more reliable than the above optional examples.

[0087] Step S204: if the low frequency period changes to the high frequency period, F2 is changed using the similarity b between the current change rules in the two most recently obtained low frequency periods and the most recently obtained high frequency period, and the changed F2 is negatively correlated with b.

[0088] When the high frequency period changes to the low frequency period in the above steps, the current change in the most recent period (i.e. the most recently obtained low frequency period and high frequency period) is used to determine the switching timing from the low frequency period to the high frequency period after being in the low frequency period (i.e. changing F1).

[0089] In this step, when the low-frequency period changes to the high-frequency period, the similarity b of the current change rules in the two most recently obtained low-frequency periods and the most recently obtained high-frequency period is changed by F2, and the changed F2 is negatively correlated with b.

[0090] In this process, if the similarity b of the change rule is large, it means that the interference situation (such as internal interference and external interference) has not changed when the current is collected according to the changed F1 in step S203. At this time, the value of F2 is reduced, so that it is easier to switch the low-frequency period and the high-frequency period with a larger current change amplitude (corresponding to the maximum change amplitude of the current in step S203). When the similarity b of the change rule is small, it means that the interference situation (such as internal interference and external interference, and may also include the current change caused by the opening and closing action) has changed. At this time, the value of F2 is increased, so that it is easier to switch the low-frequency period and the high-frequency period with a smaller current change amplitude (corresponding to the minimum change amplitude of the current in step S203).

[0091] In summary, in this process, F2 is dynamically adjusted so that F2 approaches or stabilizes at a better value in real time as the sampling process progresses. The better value refers to the ability to determine whether to use a larger current change amplitude (that is, the maximum change amplitude) or a smaller current change amplitude (that is, the minimum change amplitude) to determine the timing of changing from a low-frequency period to a high-frequency period based on the interference conditions of the current, thereby further avoiding the situation where a large amount of invalid current is collected at high speed and high frequency.

[0092] As an example, obtaining the change F2 of the similarity b of the current change rules in the two most recently obtained low-frequency periods and the most recently obtained high-frequency period includes: The currents obtained in the two most recent low-frequency periods are arranged in chronological order to obtain a sequence List3, and the currents obtained in the most recent high-frequency period constitute a sequence List2. The similarity of the changing rules between List3 and List2 is recorded as b.

[0093] The changed F2 is F2×(yb), where y represents the offset coefficient. This embodiment is described by taking y=1 as an example. In other embodiments, y can be set to other values ​​as long as the changed F2 is greater than 0.

[0094] Step S205: read out the opening and closing parameters from all the collected opening and closing currents and perform detection.

[0095] According to the above process, the current of a preset time length is collected, for example, the current is continuously collected for 4 seconds. The circuit breaker performs an opening (or closing) action within the preset time length, but the start time point and the end time point of the opening (or closing) are currently uncertain.

[0096] According to the above current collection, the start time and end time of the opening (or closing) of this embodiment will not miss the current at the start time and end time due to too low sampling frequency, nor will it introduce too much interference and invalid current limiting due to too high sampling frequency. This embodiment can obtain the start time and end time of the opening (or closing) according to the following method: The collected current is displayed on the monitor, and the start time point and the end time point are manually read out.

[0097] In some other embodiments, the method for obtaining the start time point and the end time point of the opening (or closing) operation includes: Only the current sequences collected during the high-frequency period are retained, and these current sequences are filtered separately (for example, using a Gaussian filter kernel with a length of 5 for filtering). For each filtered current sequence, a window with a length of 9 is created with each current data in the current sequence as the center, and the standard deviation of all current data in the window is obtained, which is recorded as the fluctuation amount of each current data. The fluctuation amount of all current data in all filtered current sequences is obtained, and all fluctuation amounts are divided into two categories using the Otsu threshold segmentation algorithm. In this embodiment, only the category with the largest fluctuation amount mean is retained. The current data in this category has a large fluctuation amount, indicating that the current has a large fluctuation. The fluctuation is caused by the opening and closing action. In this category, two currents that are in the same current sequence and are farthest apart in time sequence are obtained, and the moments corresponding to these two currents are used as the start time point and end time point of the opening (or closing).

[0098] As an example, the time difference between the end time point and the start time point is used as the opening and closing parameter, which represents the opening and closing time of the circuit breaker when it works in the power grid environment after leaving the factory.

[0099] In other examples, the method for obtaining the opening and closing parameters is: For the currents collected between the start time point and the end time point, the difference between the maximum and minimum values ​​of these currents is used as the opening and closing parameter, which represents the maximum current fluctuation amplitude during the opening and closing action.

[0100] In other examples, the opening and closing time and the maximum current fluctuation amplitude can be used as the opening and closing parameters; in other examples, the average value of the current collected between the start time point and the end time point can also be used as the opening and closing parameter.

[0101] The opening and closing parameters obtained above are compared with the opening and closing parameters measured when the circuit breaker leaves the factory. For example, when the absolute value of the difference between the opening and closing parameters obtained above and the opening and closing parameters measured when the circuit breaker leaves the factory is calculated, the ratio of the absolute value to the opening and closing parameters measured when the circuit breaker leaves the factory is recorded as the degree of parameter abnormality.

[0102] When the opening and closing parameters include multiple values ​​(for example, when the opening and closing time and the maximum current fluctuation amplitude are included at the same time), multiple parameter abnormality levels are obtained respectively (for example, the parameter abnormality level of the opening and closing time and the parameter abnormality level of the maximum current fluctuation amplitude).

[0103] When the parameter abnormality is greater than the preset threshold value th2, it indicates that the circuit breaker detection result is abnormal, and an alarm signal is issued at this time, and maintenance personnel confirm and repair or replace the circuit breaker. This embodiment is described by taking th2=10% as an example, and in other embodiments, th2 can be set to other values, which are not specifically limited in this embodiment.

[0104] In other embodiments, the current collected between the start time point and the end time point is displayed on a display, and the staff determines whether there is an abnormality based on the current waveform. Although this embodiment requires the staff to make a subjective judgment, it is still a common method and is more universal, so it is used as an optional embodiment for current detection.

[0105] This embodiment is now completed.

[0106] In the above embodiment, the opening and closing current is collected at a preset frequency T1. When the average change amplitude of the current is greater than the preset threshold F1, T1 is increased to a preset frequency T2 and the current is continuously collected. When the current collected at T2 has the same change rule as the current collected at T1, the current is collected again at T1. When there are different change rules, the current is continuously collected at T2. When the current generated during the opening and closing action is short-lived, the high-frequency sampling and low-frequency sampling are alternately sampled to avoid obtaining a large amount of current data with interference but invalid for the opening and closing current detection when continuously sampling the current data at a high speed, or in other words, the current generated by the opening and closing action that exists for a short time can be captured in a timely manner among a large amount of invalid currents to a certain extent.

[0107] On this basis, in this embodiment, when the high-frequency period changes to the low-frequency period, the similarity of the change rules of the current in the most recently obtained low-frequency period and the most recently obtained high-frequency period is used to change F1. The specific adjustment method is that when the similarity of the change rule is greater than the preset threshold value F2, the changed F1 is positively correlated with the maximum change amplitude of the current in the most recently obtained high-frequency period; when the similarity of the change rule is less than or equal to the preset threshold value F2, the changed F1 is positively correlated with the minimum change amplitude of the current in the most recently obtained high-frequency period. This process continuously and dynamically changes the preset threshold value F1 to dynamically control the timing of switching to the high-frequency period again when in the low-frequency period, so that it is suitable for the interference existing in the collected current, further avoiding the problem of missing the start and end time points of the opening and closing action during low-frequency sampling due to missampling, and further ensuring that the current generated by the short-term opening and closing action can be captured from a large number of interfering currents.

[0108] Furthermore, if the current moment changes from a low-frequency period to a high-frequency period, the similarity b of the current change rules in the low-frequency period obtained twice recently and the high-frequency period obtained recently is changed to F2, and the changed F2 is negatively correlated with b. In this process, if the similarity b of the change rule is large, it means that the interference situation does not change when the changed F1 collects the current. At this time, the value of F2 is reduced, so that it is easier to switch the low-frequency period and the high-frequency period with a larger current change amplitude in the future. When the similarity b of the change rule is small, it means that the interference situation has changed. At this time, the value of F2 is increased, so that it is easier to switch the low-frequency period and the high-frequency period with a smaller current change amplitude in the future. Therefore, in this process, by dynamically adjusting F2, F2 is made to approach or stabilize at a better value in real time with the sampling process. The better value refers to the ability to determine whether to use a larger current change amplitude (that is, the maximum change amplitude) or a smaller current change amplitude (that is, the minimum change amplitude) to determine the timing of changing from a low-frequency period to a high-frequency period based on the interference situation of the current, and further avoid the situation of collecting a large amount of invalid current at high speed and high frequency.

[0109] In summary, this embodiment dynamically changes F1 and F2 by changing the current when switching from the high-frequency period to the low-frequency period and then from the low-frequency period to the high-frequency period, thereby avoiding the problem of collecting a large amount of invalid interference current at high speed and high frequency, and avoiding the problem of missing the start and end time points of the opening and closing action during low-frequency sampling, further ensuring that the current generated by the short-term opening and closing action can be accurately captured from a large amount of interfering current, thereby ensuring the reliability of the current detection result.

[0110] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting the opening and closing current of a switch cabinet circuit breaker, characterized in that: The method comprises the following steps: The opening and closing current is collected at a preset frequency T1. When the average change amplitude of the current is greater than the preset threshold F1, T1 is increased to a preset frequency T2 and the current is continuously collected. When the current collected at T2 has the same change pattern as the current collected at T1, the current is collected again at T1. When the current has different change patterns, the current is continuously collected at T2. The period of time when current is collected at T1 is recorded as the low-frequency period, and the period of time when current is collected at T2 is recorded as the high-frequency period; If the current moment changes from the high-frequency period to the low-frequency period, F1 is changed by using the similarity of the change rules of the current in the most recently obtained low-frequency period and the most recently obtained high-frequency period, including: when the similarity of the change rule is greater than a preset threshold value F2, the changed F1 is positively correlated with the maximum change amplitude of the current in the most recently obtained high-frequency period; when the similarity of the change rule is less than or equal to the preset threshold value F2, the changed F1 is positively correlated with the minimum change amplitude of the current in the most recently obtained high-frequency period; If the current moment changes from a low-frequency period to a high-frequency period, F2 is changed using the similarity b of the current change rules in the two most recent low-frequency periods and the most recent high-frequency period, and the changed F2 is negatively correlated with b; The opening and closing parameters are read out from all the collected opening and closing currents and tested.

2. A method for detecting the opening and closing current of a switch cabinet circuit breaker according to claim 1, characterized in that: The method for judging whether the current collected by T2 has the same variation rule as the current collected by T1 is as follows: Record the current sequence collected at the frequency T2 as the second current sequence, record the current sequence collected at the frequency T1 before the frequency is increased to T2 as the first current sequence, and obtain the current difference between the first current sequence and the second current sequence; In the second current sequence, starting from the first current data, a current data is taken out after every other current and forms a sequence L(1), and the current difference between the first current sequence and L(1) is obtained; In the second current sequence, starting from the first current data, a current data is taken out after every two currents to form a sequence L(2), and the current difference between the first current sequence and L(2) is obtained; Similarly, in the second current sequence, starting from the first current data, a current data is taken out after every N1 currents to form a sequence L(N1), and the current difference between the first current sequence and L(N1) is obtained; N1 is a preset value; When the average of all current differences obtained is less than the preset threshold value th1, it is determined that the first current sequence and the second current sequence have the same variation rule; When the average value of all the current differences obtained is greater than or equal to the preset threshold value th1, it is determined that the first current sequence and the second current sequence do not have the same variation rule.

3. A method for detecting the opening and closing current of a switch cabinet circuit breaker according to claim 1, characterized in that: The specific steps for obtaining the similarity of the current variation rules in the most recently obtained low-frequency period and the most recently obtained high-frequency period are as follows: For the current sequence List1 formed by the current in the most recent low-frequency period, and the current sequence List2 formed by the current in the most recent high-frequency period, the current difference between List1 and List2 is recorded as x, exp(-x) is used as the similarity of the change law, and exp() represents an exponential function with a natural constant as the base.

4. A method for detecting the opening and closing current of a switch cabinet circuit breaker according to claim 1, characterized in that: The specific steps for obtaining the most recent maximum change amplitude of the current in the high-frequency period and the most recent minimum change amplitude of the current in the high-frequency period are as follows: For the current sequence List2 formed by the current in the most recently obtained high-frequency time period, the difference between every two adjacent current data in List2 is calculated; the differences of all adjacent current data in List2 are clustered into several categories, and the mean of all differences in each category is calculated. For the category with the largest mean of all differences, the mean of all differences in the category with the largest mean is used as the maximum change amplitude; for the category with the smallest mean of all differences, the mean of all differences in the category with the smallest mean is used as the minimum change amplitude.

5. A method for detecting the opening and closing current of a switch cabinet circuit breaker according to claim 1, characterized in that: When the similarity of the change rule is greater than the preset threshold value F2, the changed F1 is positively correlated with the maximum change amplitude of the current in the most recently obtained high-frequency period; When the similarity of the change rule is less than or equal to the preset threshold value F2, the changed F1 is positively correlated with the minimum change amplitude of the current in the most recently obtained high-frequency period, including the specific formula as follows: When the similarity of the change rule is greater than the preset threshold value F2, w×f1+(1-w)×F1 is used as the changed F1; when the similarity of the change rule is less than or equal to the preset threshold value F2, w×F1+(1-w)×f2 is used as the changed F1; Where w represents the similarity of the changing rules; f1 and f2 represent the maximum and minimum change ranges.

6. A method for detecting the opening and closing current of a switch cabinet circuit breaker according to claim 1, characterized in that: The specific steps for obtaining the similarity b of the current change rules in the two most recently obtained low-frequency periods and the most recently obtained high-frequency period are as follows: The currents obtained in the two most recent low-frequency periods are arranged in chronological order to obtain a sequence List3, and the currents obtained in the most recent high-frequency period constitute a sequence List2. The similarity of the changing rules between List3 and List2 is recorded as b.

7. A method for detecting the opening and closing current of a switch cabinet circuit breaker according to claim 1, characterized in that: The specific formula for changing F2 by using the similarity b of the current change rules in the two most recently obtained low-frequency periods and the most recently obtained high-frequency period is as follows: The changed F2 is F2×(yb), where y represents a preset offset coefficient.

8. A method for detecting the opening and closing current of a switch cabinet circuit breaker according to claim 1, characterized in that: The specific steps of reading the opening and closing parameters from all the collected opening and closing currents and performing detection include the following: The start time point and the end time point of the opening and closing action are read out from all the collected opening and closing currents; the time difference between the end time point and the start time point is used as the opening and closing parameter, and the absolute value of the difference between the obtained opening and closing parameters and the opening and closing parameters measured when the circuit breaker leaves the factory is calculated. The ratio of the absolute value to the opening and closing parameters measured when the circuit breaker leaves the factory is recorded as the parameter abnormality degree. When the parameter abnormality degree is greater than the preset threshold value th2, it is determined that the current detection result obtained by the circuit breaker is abnormal.

9. A method for detecting the opening and closing current of a switch cabinet circuit breaker according to claim 2 or 3, characterized in that: The specific steps for obtaining the current difference are as follows: Linear normalization is performed on any two current sequences respectively, and the DTW distance between any two current sequences after linear normalization is recorded as the current difference.

10. A switch cabinet circuit breaker opening and closing current detection system, the system comprising a detection device and a display, the detection device comprising an opening current sensor and a closing current sensor for collecting opening and closing currents, the display for displaying the opening and closing currents; the detection device also comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for detecting the opening and closing current of a switch cabinet circuit breaker as described in any one of claims 1 to 9 are implemented.

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