Safety power-on testing methods, equipment, and systems for electrical distribution cabinets

Abstract

This application relates to the field of electrical variable monitoring technology, specifically to a method, equipment, and system for safe power-on testing of distribution cabinets. The method includes: acquiring the three-phase voltage signals of the distribution cabinet during the safe power-on test; analyzing the similarity between the three-phase voltage signals and the fluctuation degree of each phase voltage to obtain the three-phase fluctuation characteristic values ​​of the three-phase voltage signals; constructing the peak difference rate between any two phase voltage signals based on the peak difference degree between the three-phase voltage signals, thereby obtaining the electromagnetic interference factor of the three-phase voltage signals; and constructing anomaly judgment values ​​for each phase voltage based on the electromagnetic interference factor combined with the deviation degree of each phase voltage to determine the abnormal operation of the distribution cabinet. This application can improve the accuracy of safe power-on testing of distribution cabinets.

Description

Technical Field

[0001] This application relates to the field of electrical variable monitoring technology, specifically to a method, equipment, and system for safety power-on testing of distribution cabinets. Background Technology

[0002] Distribution cabinets are mainly used for power distribution, circuit control, and fault protection in power systems. They are electrical devices that ensure the safe, stable, and efficient distribution of power. During factory inspection, on-site installation, and maintenance, safe power-on testing methods are typically used to test the electrical and safety performance of distribution cabinets. This allows for the timely detection of defects and potential problems, ensuring their reliability and safety in subsequent operation.

[0003] Currently, the main method for testing the safety of power distribution cabinets is to apply a standard test power supply to the cabinet under test and monitor the voltage and its changes to determine whether there are any abnormalities in the cabinet circuit. However, in actual engineering testing environments, there is usually complex electromagnetic interference around the power distribution cabinet, which can significantly affect the voltage acquisition circuit. This can cause significant fluctuations in the voltage acquired by the power-on testing equipment, especially frequent and unstable fluctuations in the three-phase voltage. This can lead to misjudgments by the testing system, misidentifying a normally operating power distribution cabinet as having an electrical abnormality, thus affecting the accuracy and reliability of the test results. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this application is to provide a method, equipment, and system for safe power-on testing of distribution cabinets. The specific technical solution adopted is as follows: In a first aspect, embodiments of this application provide a method for a safety power-on test of a power distribution cabinet, comprising the following steps: Acquire the three-phase voltage signals of the distribution cabinet during the safety power-on test; The similarity between the three-phase voltage signals of the distribution cabinet and the fluctuation of each phase voltage of the distribution cabinet are analyzed to obtain the three-phase fluctuation characteristic value of the three-phase voltage signal. Based on the peak difference between the three-phase voltage signals, the peak difference rate between any two phase voltage signals is constructed, and then the electromagnetic interference factor of the three-phase voltage signal is obtained. Based on the electromagnetic interference factor and the deviation of each phase voltage, an abnormal judgment value for each phase voltage is constructed to determine the abnormal operation of the distribution cabinet.

[0005] Preferably, the formula for obtaining the three-phase fluctuation characteristic value of the three-phase voltage signal is: In the formula, This represents the three-phase fluctuation characteristic value of the three-phase voltage signal. 'b' represents the first mean of the three-phase voltage signal, and 'b' represents the second mean of the three-phase voltage signal. To avoid constants with a denominator of zero; Wherein, the first mean is the mean of the absolute values ​​of the similarity between any two phase voltages.

[0006] Preferably, the process of obtaining the second mean is as follows: the calculation formula for the phase voltage fluctuation of each phase voltage is: ,in, This refers to the phase voltage fluctuation of the first phase. These represent the maximum and minimum values ​​of the peak amplitude in the first phase voltage signal, respectively. This represents the average amplitude of all peak points; The average of the three phase voltage fluctuations is used as the second average.

[0007] Preferably, the formula for obtaining the peak difference rate between any two phase voltage signals is: In the formula, This represents the peak difference rate between the first and second phase voltage signals. This indicates taking the maximum value. These represent the third average values ​​of the first and second phase voltage signals, respectively, where the third average value of each phase voltage signal is the average value of the peak values ​​of each phase voltage signal.

[0008] Preferably, the formula for obtaining the electromagnetic interference factor of the three-phase voltage signal is: In the formula, The electromagnetic interference factor representing a three-phase voltage signal. This represents the three-phase fluctuation characteristic value of the three-phase voltage signal. The fourth mean of the three-phase voltage signal is represented by the mean of the peak difference rate calculated from any two phase voltage signals.

[0009] Preferably, the formula for obtaining the abnormal voltage judgment value of each phase is: In the formula, This is the abnormal judgment value for the first phase voltage. This indicates the degree of deviation between the current first-phase voltage and the standard test voltage. The electromagnetic interference factor represents the three-phase voltage signal.

[0010] Preferably, the formula for obtaining the deviation of the first phase voltage from the standard test voltage at the current moment is: ,in, These represent the effective value of the first phase voltage and the standard test voltage value at the current moment, respectively.

[0011] Secondly, embodiments of this application also provide a safety power-on testing system for a power distribution cabinet, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any of the above-described safety power-on testing methods for a power distribution cabinet.

[0012] Thirdly, embodiments of this application also provide a safety power-on testing device for a power distribution cabinet, wherein the device stores a computer program, and when the computer program is executed by a processor, it implements any of the above-described safety power-on testing methods for a power distribution cabinet.

[0013] As can be seen from the above, the safety power-on testing method, equipment, and system for distribution cabinets provided in this application have at least the following beneficial effects: This application addresses the problem that current safe power-on testing methods neglect complex electromagnetic interference around the distribution cabinet, leading to inaccurate test results for abnormal distribution cabinets. This application constructs three-phase fluctuation characteristic values ​​based on the fluctuation characteristics between the three-phase voltage signals in the distribution cabinet circuit. Furthermore, based on the peak value differences of the three-phase voltage signals, combined with the three-phase fluctuation characteristic values, an electromagnetic interference factor is obtained. This factor is used to analyze the deviation of the three-phase voltage values, thereby obtaining accurate anomaly judgment values ​​and achieving precise safe power-on testing of the distribution cabinet. This application can effectively improve the impact of electromagnetic interference on the distribution cabinet, enhance the accuracy and efficiency of abnormal distribution cabinet testing, and avoid misjudging normally operating distribution cabinets as having electrical anomalies. Attached Figure Description

[0014] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A flowchart illustrating the steps of the safety power-on test method for a distribution cabinet provided in this application. Detailed Implementation

[0016] To further illustrate the technical means and effects adopted by this application to achieve the intended purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation methods, structures, features, and effects of the safety power-on testing method, equipment, and system for power distribution cabinets proposed in this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0017] Unless otherwise specified and limited, terms such as “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a circuit structure, article, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the article or device that includes said element. Furthermore, the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. 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 application pertains.

[0018] The following description, in conjunction with the accompanying drawings, details the specific scheme of the safety power-on test method, equipment, and system for distribution cabinets provided in this application.

[0019] Please see Figure 1 It illustrates a flowchart of a safety power-on test method for a power distribution cabinet according to an embodiment of this application, including the following steps: When testing large frequency converters or high-frequency inductive loads in industrial settings, conducted electromagnetic interference with an extremely wide frequency band and non-periodicity may occur. Conventional hardware low-pass filters cannot completely filter out such random and sudden fluctuations, and secondary correction is required through fluctuation characteristic analysis.

[0020] Step 1: Obtain the three-phase voltage signal of the distribution cabinet during the safe power-on test.

[0021] First, a standard test voltage is applied to the distribution cabinet under test by the safety power-on test vehicle. The specific standard test voltage value is not specifically limited and can be set by the implementer according to the equipment parameters. In this embodiment, it is set to 220V, and the power-on test duration is 1 minute. The safety power-on test vehicle then collects the three-phase voltage signals in the distribution cabinet circuit at a sampling frequency of 1kHz and a sampling duration of 1 second. The three-phase voltage signals have undergone phase correction to eliminate phase deviation, and the three-phase voltage values ​​at the current test moment are recorded in real time. It should be noted that phase correction is a well-known technique, and its specific implementation will not be elaborated upon.

[0022] Step 2: Analyze the similarity between the three-phase voltage signals of the distribution cabinet and the fluctuation of each phase voltage of the distribution cabinet to obtain the three-phase fluctuation characteristic value of the three-phase voltage signal. Based on the peak difference between the three-phase voltage signals, construct the peak difference rate between any two phase voltage signals, and then obtain the electromagnetic interference factor of the three-phase voltage signal.

[0023] S1: Analyze the similarity between the three-phase voltage signals of the distribution cabinet and the fluctuation of each phase voltage of the distribution cabinet to obtain the three-phase fluctuation characteristic value of the three-phase voltage signal.

[0024] Electrical equipment, such as distribution cabinets, often generate complex electromagnetic interference, which affects the three-phase voltage signals of the circuit. This leads to frequent random fluctuations in the three-phase voltage monitored by the safety power-on test equipment, resulting in low similarity between the three-phase voltage signals under electromagnetic interference.

[0025] To analyze the similarity between three-phase voltage signals, cosine similarity is used to calculate the pairwise similarity between the three-phase voltages, obtaining three sets of similarity scores. In this embodiment, cosine similarity is used to measure the similarity between any two-phase voltages. Furthermore, the average of the absolute values ​​of all the similarities between any two-phase voltages is taken as the first average, reflecting the degree of similarity in the fluctuations between the three-phase voltage signals. Cosine similarity is a well-known technique, and its specific implementation will not be described in detail.

[0026] Furthermore, this embodiment will analyze the fluctuation degree of each phase voltage. Taking the voltage signal of the first phase as an example, the voltage signal of the first phase is used as the input of the peak detection algorithm. The peak detection algorithm can be MK, AMPD, etc., without special restrictions. This embodiment selects the AMPD algorithm to obtain the peak point of the voltage signal. The peak point amplitude refers to the voltage amplitude of the peak point of each positive half-cycle of the AC cycle extracted by the peak detection algorithm. Then, the calculation is performed. ,Will The phase voltage fluctuation of the first phase reflects the degree of fluctuation in the voltage signal of each phase. These represent the maximum and minimum values ​​of the peak amplitude, respectively. This represents the average amplitude of all peak points. The phase voltage fluctuation of the other two phase voltage signals is calculated using the same method. The average of the three phase voltage fluctuations is recorded as the second average, which reflects the fluctuation of the entire three-phase voltage signal.

[0027] Among them, the smaller the first mean, the lower the similarity of fluctuations among the three-phase voltage signals; the larger the second mean, the higher the fluctuation of the entire three-phase voltage signal, indicating that the electromagnetic interference from the distribution cabinet is stronger during the safe power-on test.

[0028] Based on the above analysis, the three-phase fluctuation characteristic value of the three-phase voltage signal is calculated to characterize the fluctuation degree of the three-phase voltage signal of the safety power-on test equipment under electromagnetic interference of the distribution cabinet. The specific expression of the three-phase fluctuation characteristic value is as follows: In the formula, This represents the three-phase fluctuation characteristic value of the three-phase voltage signal. 'b' represents the first mean of the three-phase voltage signal, and 'b' represents the second mean of the three-phase voltage signal. To avoid constants with a denominator of zero, the value range is 0.01-0.1, without any special restrictions. In this embodiment, the value is 0.05.

[0029] It should be noted that, The mean of the similarity is dimensionless. The average value of the phase voltage fluctuation is given by the ratio of the peak amplitudes of the voltage signals, and is dimensionless; therefore, the characteristic value of the three-phase fluctuation is... Dimensionless.

[0030] In existing data analysis methods, if the target being analyzed comprises multiple parts, and these parts are similar, the average value of the same characteristic index of these parts is typically used to analyze the overall characteristics of the target. In this scheme, the three-phase voltage signal consists of three parallel voltage signals. Therefore, the average similarity of the three voltage signals and the average phase voltage fluctuation are used as the first and second averages to describe the fluctuation characteristics of the three-phase voltage signal. Then, based on the first and second averages and the positive and negative relationships of the three-phase voltage fluctuation characteristics, a three-phase fluctuation characteristic value is constructed, representing the degree of fluctuation of the three-phase voltage signal of the safety power-on test equipment under electromagnetic interference from the distribution cabinet.

[0031] S2: Construct the peak difference rate between any two phase voltage signals based on the peak difference between the three-phase voltage signals, and then obtain the electromagnetic interference factor of the three-phase voltage signals.

[0032] When there is an abnormality in the distribution cabinet under test, the three-phase voltage will also fluctuate. For example, if one phase voltage is low at 200V and the other two phase voltages are normal at 220V, the difference in the three-phase voltage will make the first mean value smaller, which will lead to a larger three-phase fluctuation characteristic value. Therefore, it is necessary to further analyze the abnormal voltage characteristics of the distribution cabinet under test.

[0033] When the safety power-on test equipment is under ideal conditions and is not subject to electromagnetic interference, when the power distribution cabinet malfunctions, the voltage of the abnormal phase and the normal phase remains stable. For example, the voltage signal remains stable at 200V or 220V without frequent fluctuations. Even when subjected to electromagnetic interference, the voltage signal still fluctuates around the stable voltage.

[0034] To analyze the abnormal differences between the peak values ​​of the three-phase voltage signals, the mean value of the peak value of each phase voltage signal is first calculated and denoted as the third mean value, reflecting the average level of the peak value of each phase voltage signal. Next, based on the principle of rate of change calculation, the peak difference rate between any two voltage signals in the three-phase voltage signals is calculated. Taking the peak difference rate between the first and second phase voltage signals as an example, the calculation is... , This represents the peak difference rate between the first and second phase voltage signals. These represent the third average values ​​of the first and second phase voltage signals, respectively. This means taking the maximum value to ensure the calculated difference rate is within the range of 0-1. It should be noted that in practical applications, if... A value of 0 indicates that no three-phase voltage signal can be detected after power-on, indicating an anomaly in the tested distribution cabinet. In this case, the denominator is zero, and no further calculations are performed, nor is an alarm issued. Then, the average of the peak difference rates calculated from any two phase voltage signals is recorded as the fourth mean, representing the degree of difference between the peak values ​​of the three-phase voltage signals under electromagnetic interference. The larger the fourth mean, the greater the voltage level difference of the three-phase voltage signals, and the more likely the distribution cabinet is to have an anomaly, resulting in larger three-phase fluctuation characteristic values.

[0035] Based on the above analysis, the electromagnetic interference factor of the three-phase voltage signal is calculated to characterize the degree of electromagnetic interference affecting the three-phase voltage signal monitored by the safety power-on test equipment. The specific expression for the electromagnetic interference factor is as follows: In the formula, The electromagnetic interference factor representing a three-phase voltage signal. This represents the fourth mean value of the three-phase voltage signal, used to characterize the three-phase fluctuations. Correction is necessary because when there is an anomaly in the distribution cabinet itself, the c value will be larger, meaning a greater difference in the three-phase voltage signals, which will result in a smaller first mean value, thus leading to a decrease in the three-phase fluctuation characteristic value. If A is too large, the larger A becomes, therefore A needs to be corrected to be smaller. This represents the hyperbolic tangent function, used to normalize the electromagnetic interference factor. The preset maximum suppression coefficient ranges from 0.1 to 0.3. In this embodiment, the value is 0.15. Its function is to limit the electromagnetic interference factor to correct the amplitude and avoid subsequent false detections.

[0036] Dimensional explanation: It is obtained from the mean of the difference rate of the three-phase average voltage and is dimensionless.

[0037] In this embodiment, the three-phase fluctuation characteristic value is too large due to the abnormal factors of the distribution cabinet. The fourth mean value is used as a correction factor to correct the three-phase fluctuation characteristic value, so as to obtain the electromagnetic interference factor, which is used to reflect the degree of electromagnetic interference affecting the three-phase voltage signal monitored by the safe power-on test equipment.

[0038] Step 3: Based on the electromagnetic interference factor and the deviation of each phase voltage, construct the abnormal judgment value of each phase voltage to determine the abnormal operation of the distribution cabinet.

[0039] Obtain the three-phase voltage values ​​monitored at the current moment. Based on the principle of rate of change calculation, calculate the deviation of each phase voltage from the standard test voltage. Taking the first phase voltage value as an example, calculate... ,in This indicates the degree of deviation between the current first-phase voltage and the standard test voltage. These represent the effective value of the first phase voltage and the standard test voltage value at the current moment, respectively. The standard test voltage value is set by the implementer in the actual application scenario, and this embodiment does not impose any special restrictions on it. In this embodiment, the standard test voltage is 220V.

[0040] Then use electromagnetic interference factor to Performing coefficient correction, due to environmental electromagnetic interference, will increase the three-phase voltage imbalance, leading to... Too large, therefore it needs to be adjusted according to the electromagnetic interference factor. The correction needs to be made towards a smaller value; the first phase voltage anomaly determination value is... In the formula, The abnormal judgment value for the first phase voltage is used as the basis for calculating the abnormal judgment values ​​for the other two phase voltages using the same method. .

[0041] Furthermore, if the abnormal judgment values ​​of the three-phase voltages do not exceed the preset threshold (7% in this example), the distribution cabinet is operating normally. Therefore, the three abnormal judgment values ​​are compared with 7% respectively. If the abnormal judgment values ​​are all less than or equal to 7%, the distribution cabinet under test is operating normally; otherwise, it indicates that there is an abnormality in the distribution cabinet under test, an alarm is issued and the power is immediately stopped, and the staff checks the abnormality of the distribution cabinet.

[0042] Based on the same inventive concept as the above methods, this application also provides a safety power-on test system for power distribution cabinets, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above methods for safety power-on test of power distribution cabinets.

[0043] Meanwhile, this application embodiment also provides a safety power-on test device for a power distribution cabinet, wherein the device stores a computer program, and when the computer program is executed by a processor, it implements any of the above-described safety power-on test methods for a power distribution cabinet.

[0044] It is understood that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0045] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0046] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Any equivalent structural or procedural transformations made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the protection scope of this application.

Claims

1. A method for safety power-on testing of a power distribution cabinet, characterized in that, Includes the following steps: Acquire the three-phase voltage signals of the distribution cabinet during the safety power-on test; The similarity between the three-phase voltage signals of the distribution cabinet and the fluctuation of each phase voltage of the distribution cabinet are analyzed to obtain the three-phase fluctuation characteristic value of the three-phase voltage signal. Based on the peak difference between the three-phase voltage signals, the peak difference rate between any two phase voltage signals is constructed, and then the electromagnetic interference factor of the three-phase voltage signal is obtained. Based on the electromagnetic interference factor and the deviation of each phase voltage, an abnormal judgment value for each phase voltage is constructed to determine the abnormal operation of the distribution cabinet. The formula for obtaining the three-phase fluctuation characteristic value of the three-phase voltage signal is as follows: In the formula, This represents the three-phase fluctuation characteristic value of the three-phase voltage signal. 'b' represents the first mean of the three-phase voltage signal, and 'b' represents the second mean of the three-phase voltage signal. To avoid constants with a denominator of zero; Wherein, the first mean is the mean of the absolute values ​​of the similarity between any two phase voltages; The process of obtaining the second mean is as follows: the formula for calculating the phase voltage fluctuation of each phase voltage is: ,in, This refers to the phase voltage fluctuation of the first phase. These represent the maximum and minimum values ​​of the peak amplitude in the first phase voltage signal, respectively. This represents the average amplitude of all peak points; Among them, the average of the three phase voltage fluctuations is used as the second average; The formula for obtaining the peak difference rate between any two phase voltage signals is: In the formula, This represents the peak difference rate between the first and second phase voltage signals. This indicates taking the maximum value. These represent the third average values ​​of the first and second phase voltage signals, respectively, where the third average value of each phase voltage signal is the average value of the peak values ​​of each phase voltage signal. The formula for obtaining the electromagnetic interference factor of the three-phase voltage signal is: In the formula, The electromagnetic interference factor representing a three-phase voltage signal. This represents the three-phase fluctuation characteristic value of the three-phase voltage signal. The fourth mean of the three-phase voltage signal is represented by the mean of the peak difference rate calculated from any two phase voltage signals. The formula for obtaining the abnormal voltage judgment value of each phase is: In the formula, This is the abnormal judgment value for the first phase voltage. This indicates the degree of deviation between the current first-phase voltage and the standard test voltage. The electromagnetic interference factor represents the three-phase voltage signal.

2. The safety power-on test method for a distribution cabinet as described in claim 1, characterized in that, The formula for obtaining the deviation of the first phase voltage from the standard test voltage at the current moment is: ,in, These represent the effective value of the first phase voltage and the standard test voltage value at the current moment, respectively.

3. The safety power-on test method for a distribution cabinet as described in claim 1, characterized in that, When all three-phase voltage abnormality judgment values ​​are less than the preset threshold, the tested distribution cabinet is operating normally; otherwise, the tested distribution cabinet is operating abnormally.

4. A safety power-on testing system for a power distribution cabinet, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the safety power-on test method for a power distribution cabinet as described in any one of claims 1-3.

5. A safety power-on testing device for a power distribution cabinet, wherein the device stores a computer program, characterized in that, When the computer program is executed by the processor, it implements the safety power-on test method for power distribution cabinets as described in any one of claims 1-3.

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