A broadband standard voltage divider for withstand voltage test of electrical equipment

Abstract

The present invention relates to the technical field of broadband standard voltage dividers, and specifically discloses a broadband standard voltage divider for the withstand voltage test of power equipment. The system includes: a voltage division ratio evaluation module under frequency conditions, a voltage division ratio evaluation module under temperature conditions, a voltage division ratio accuracy evaluation module, a withstand voltage test information acquisition module, and an equipment withstand voltage performance evaluation module; by analyzing the voltage division ratio of the broadband standard voltage divider under different frequencies, different voltages, and different test temperatures, and then deeply analyzing the uniformity of the voltage boost speed during the voltage boost stage, the voltage stability during the full voltage stage, and the uniformity of the voltage drop speed during the voltage drop stage of the broadband standard voltage divider, the influence factors of the withstand voltage test are set, which improves the comprehensiveness and accuracy of the correction of the voltage division ratio accuracy of the broadband standard voltage divider, improves the stability of the acquisition of withstand voltage test data, thereby accurately evaluating the withstand voltage capacity of power equipment, and further ensuring the safety of power equipment during subsequent operation.

Description

Technical Field

[0001] The present invention relates to the technical field of broadband standard voltage dividers, and more specifically, to a broadband standard voltage divider for the withstand voltage test of power equipment. Background Art

[0002] In the power system, the withstand voltage performance of power equipment is a key factor to ensure its safe and reliable operation. In order to accurately evaluate the withstand voltage capacity of power equipment, a broadband standard voltage divider is required for voltage measurement and monitoring. Traditional voltage dividers have problems such as unstable voltage division ratio and susceptibility to environmental interference in the broadband range, and cannot meet the requirements of high-precision withstand voltage tests. Therefore, a broadband standard voltage divider is needed for the withstand voltage test of power equipment.

[0003] For example, the patent with the Chinese patent publication number CN115542231A discloses a broadband calibration device based on a standard source, including: a broadband standard source generator for outputting voltage and current standard signals with adjustable frequencies and amplitudes. A broadband voltage and current reference signal acquisition module for acquiring the voltage and current standard signals output by the broadband standard source generator and using the voltage and current standard signals as broadband voltage and current reference signals. A broadband differential voltage and current signal acquisition module for dividing the broadband voltage reference signal to obtain a broadband voltage in-phase component, and obtaining a broadband voltage quadrature component through an orthogonal waveform generator. Combining the broadband voltage in-phase component and the broadband voltage quadrature component to form a broadband voltage differential signal. Obtaining a broadband current differential signal by converting the broadband voltage differential signal. A calibration module for calibrating and verifying the broadband calibrator using the broadband voltage and current reference signals and the broadband voltage and current differential signals. Solving the problem of inability to perform broadband overall calibration.

[0004] For example, the patent with the Chinese patent publication number CN205139353U discloses an automatic calibration device for an AC voltage divider, including: an industrial control computer system, a broadband high-stability power supply, an intermediate-frequency step-up transformer, and a standard broadband voltage divider connected in sequence. The standard broadband voltage divider is used to be connected in parallel with the AC voltage divider to be tested. The industrial control computer system is used to issue a control signal to control the frequency and amplitude of the voltage output by the broadband high-stability power supply according to the preset voltage detection points, sample the voltage of the standard broadband voltage divider, and use feedback automatic control to adjust the error between the voltage at the high-voltage end of the standard broadband voltage divider and the target set voltage. When the voltage at the high-voltage end of the standard broadband voltage divider reaches the preset voltage detection point, the voltage boost is automatically stopped. The intermediate-frequency step-up transformer is used to boost the output voltage of the broadband high-stability power supply and output it to the standard broadband voltage divider and the AC voltage divider to be tested. The utility model has stable output voltage, small waveform distortion rate, and small frequency deviation, can avoid the reading change of the resistive-capacitive voltage divider caused by voltage quality problems, and the whole detection and calibration process is fully automatic, which can avoid operation errors in the manual voltage regulation or mechanical voltage regulation process.

[0005] The above prior art still has the following problems in the withstand voltage test of power equipment: 1. Only the voltage division ratio of the broadband standard voltage divider at different frequencies and different voltage amplitudes is corrected, and the accuracy of the voltage division ratio of the broadband standard voltage divider at different test temperatures is not deeply analyzed, reducing the comprehensiveness and accuracy of the correction of the voltage division ratio accuracy of the broadband standard voltage divider, and unable to provide reliable test data for the subsequent withstand voltage performance test of power equipment, thus reducing the reliability of the analysis of the withstand voltage performance of power equipment.

[0006] 2. The voltage changes of the broadband standard voltage divider during the voltage rising stage, full voltage stage and voltage dropping stage are not deeply analyzed, that is, in the withstand voltage test of power equipment, the influence of the voltage conditions of the broadband standard voltage divider at different working stages on the withstand voltage performance is not analyzed, and the withstand voltage test data cannot be accurately obtained, reducing the stability of obtaining the withstand voltage test data, thus unable to accurately evaluate the withstand voltage ability of power equipment, and further unable to ensure the safety of power equipment during subsequent operation. Summary of the Invention

[0007] In view of this, to solve the problems raised in the above background technology, a broadband standard voltage divider for the withstand voltage test of power equipment is proposed.

[0008] The object of the present invention can be achieved by the following technical solutions: The present invention provides a broadband standard voltage divider for the withstand voltage test of power equipment, including: a voltage division ratio evaluation module under frequency conditions, which is used to record the target broadband standard voltage divider as the target voltage divider, extract the nominal voltage division ratio of the target voltage divider, extract the high voltage output by the standard voltage source to the target voltage divider at each frequency point, collect the low voltage at the low voltage end of the target voltage divider corresponding to each output at each frequency point, and analyze the accuracy of the voltage division ratio of the target voltage divider at each frequency point.

[0009] A voltage division ratio evaluation module under temperature conditions, which is used to place the target voltage divider in an environmental chamber with temperature control, extract the high voltage output by the standard voltage source to the target voltage divider, collect the low voltage at the low voltage end of the target voltage divider at each test temperature, and analyze the accuracy of the voltage division ratio of the target voltage divider at each test temperature.

[0010] A voltage division ratio accuracy evaluation module, which is used to evaluate whether there is an abnormality in the voltage division ratio accuracy of the target voltage divider. If not, the withstand voltage test information collection module is executed. If so, it indicates that the target voltage divider cannot be used for the withstand voltage test of power equipment and gives feedback.

[0011] A withstand voltage test information collection module, which is used to extract the standard test voltage value corresponding to the low voltage end of the target voltage divider during the full voltage stage, collect the voltage values corresponding to each monitoring time point at the low voltage end of the target voltage divider during the voltage rising stage, full voltage stage and voltage dropping stage, and collect the withstand voltage information corresponding to the target power equipment during the withstand voltage test.

[0012] A device withstand voltage performance evaluation module is used to set the influence factors corresponding to a target power device in a withstand voltage test, evaluate whether there are problems with the withstand voltage performance of the target power device in the withstand voltage test. If there are problems, it indicates that the target power device cannot withstand voltage and gives feedback. If there are no problems, it indicates that the withstand voltage performance of the target power device is intact.

[0013] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: (1) By analyzing the voltage division ratios of the broadband standard voltage divider at different frequencies and different voltage amplitudes and the voltage division ratios at different test temperatures, the present invention evaluates whether there are abnormalities in the accuracy of the voltage division ratio of the voltage divider, improves the comprehensiveness and accuracy of the correction of the voltage division ratio accuracy of the broadband standard voltage divider, provides reliable test data for subsequent withstand voltage performance tests of power devices, and thus improves the reliability of the analysis of the withstand voltage performance of power devices.

[0014] (2) By deeply analyzing the uniformity of the voltage rise speed in the voltage rise stage, the voltage stability in the full voltage stage, and the uniformity of the voltage drop speed in the voltage drop stage of the broadband standard voltage divider, the present invention sets the influence factors corresponding to the power device in the withstand voltage test, accurately obtains the withstand voltage test data, improves the stability of the acquisition of the withstand voltage test data, thus accurately evaluates the withstand voltage ability of the power device, and further ensures the safety of the power device in subsequent operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a schematic diagram of the connection of the system module structure of the present invention.

[0017] Figure 2 It is a flowchart for evaluating the accuracy of the voltage division ratio of the target voltage divider of the present invention.

[0018] Figure 3 It is a flowchart for evaluating the withstand voltage performance of the power device of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] Please refer to Figure 1 As shown, the present invention provides a broadband standard voltage divider for the withstand voltage test of power equipment, including: a voltage division ratio evaluation module under frequency conditions, a voltage division ratio evaluation module under temperature conditions, a voltage division ratio accuracy evaluation module, a withstand voltage test information acquisition module, and an equipment withstand voltage performance evaluation module.

[0021] Both the voltage division ratio evaluation module under frequency conditions and the voltage division ratio evaluation module under temperature conditions are connected to the voltage division ratio accuracy evaluation module. The voltage division ratio accuracy evaluation module is connected to the withstand voltage test information acquisition module, and the withstand voltage test information acquisition module is connected to the equipment withstand voltage performance evaluation module.

[0022] The voltage division ratio evaluation module under frequency conditions is used to record the target broadband standard voltage divider as the target voltage divider, extract the nominal voltage division ratio of the target voltage divider, extract the high voltage output by the standard voltage source to the target voltage divider at each frequency point, collect the low voltage at the low voltage end after each output of the target voltage divider at each frequency point, and analyze the voltage division ratio accuracy of the target voltage divider at each frequency point.

[0023] It should be noted that the nominal voltage division ratio of the target voltage divider is directly extracted from the factory label of the target voltage divider. The high voltage output by the standard voltage source to the target voltage divider at each frequency point is directly extracted from the voltage output display screen of the standard voltage source. The low voltage at the low voltage end after each output of the target voltage divider at each frequency point is collected from the voltmeter connected to the low voltage end of the target voltage divider.

[0024] In a specific embodiment of the present invention, the frequency points include but are not limited to 1 kHz, 10 kHz, 20 kHz, 50 kHz, and 100 kHz.

[0025] In a specific embodiment of the present invention, the specific process of analyzing the voltage division ratio accuracy of the target voltage divider at each frequency point is as follows: Denote the high voltage output by the standard voltage source to the target voltage divider at each frequency point as where i represents the number of the frequency point, i = 1, 2,..., n, and j represents the number of each output, j = 1, 2,..., m.

[0026] Denote the low voltage at the low voltage end after each output of the target voltage divider at each frequency point as

[0027] Denote the nominal voltage division ratio of the target voltage divider as K 标 .

[0028] Calculate the voltage division ratio accuracy of the target voltage divider at each frequency point where, △K represents the deviation of the voltage division ratio set for reference, and m represents the number of output times.

[0029] The voltage division ratio evaluation module under the said temperature condition is used to place the target voltage divider in an environment chamber with temperature control, extract the high voltage output by the standard voltage source to the target voltage divider, collect the low voltage at the low voltage end of the target voltage divider at each test temperature, and analyze the voltage division ratio accuracy of the target voltage divider at each test temperature.

[0030] It should be noted that the high voltage output by the standard voltage source to the target voltage divider is extracted from the voltage output display screen of the standard voltage source, and the low voltage at the low voltage end of the target voltage divider at each test temperature is also collected from the voltmeter connected to the low voltage end of the target voltage divider.

[0031] In a specific embodiment of the present invention, the specific process of analyzing the voltage division ratio accuracy of the target voltage divider at each test temperature is: Denote the high voltage output by the standard voltage source to the target voltage divider as U 高 .

[0032] Denote the low voltage at the low voltage end of the target voltage divider at each test temperature as where, g represents the number of the test temperature, and g = 1, 2,..., p.

[0033] Calculate the voltage division ratio accuracy of the target voltage divider at each test temperature

[0034] The voltage division ratio accuracy evaluation module is used to evaluate whether there is an abnormality in the voltage division ratio accuracy of the target voltage divider. If not, execute the withstand voltage test information acquisition module. If so, it indicates that the target voltage divider cannot be used for the withstand voltage test of power equipment and give feedback.

[0035] Please refer to Figure 2 As shown, in a specific embodiment of the present invention, the specific process of evaluating whether there is an abnormality in the voltage division ratio accuracy of the target voltage divider is: Calculate the voltage division ratio accuracy β of the target voltage divider where, β 频 and β 温 respectively represent the voltage division ratio accuracy set for reference at the frequency level and at the test temperature level, n represents the number of frequency points, and p represents the number of test temperatures.

[0036] Compare the voltage division ratio accuracy of the target voltage divider with the set reference voltage division ratio accuracy. If the voltage division ratio accuracy of the target voltage divider is greater than or equal to the set reference voltage division ratio accuracy, it indicates that there is no abnormality in the voltage division ratio accuracy of the target voltage divider. Otherwise, it indicates that there is an abnormality in the voltage division ratio accuracy of the target voltage divider.

[0037] In the embodiments of the present invention, by analyzing the voltage division ratios of the broadband standard voltage divider at different frequencies and different voltage amplitudes and the voltage division ratios at different test temperatures, it is evaluated whether there is an abnormality in the voltage division ratio accuracy of the voltage divider, improving the comprehensiveness and accuracy of the correction of the voltage division ratio accuracy of the broadband standard voltage divider, providing reliable test data for subsequent power equipment withstand voltage performance tests, and thus improving the reliability of power equipment withstand voltage performance analysis.

[0038] The withstand voltage test information acquisition module is used to extract the standard test voltage value corresponding to the low-voltage end of the target voltage divider during the full-voltage stage, collect the voltage values corresponding to each monitoring time point of the low-voltage end of the target voltage divider during the voltage-rise stage, the full-voltage stage, and the voltage-drop stage, and collect the withstand voltage information corresponding to the target power equipment during the withstand voltage test.

[0039] It should be noted that the confirmation method of the standard test voltage value corresponding to the low-voltage end of the target voltage divider during the full-voltage stage is as follows: Determine the test voltage according to the type, rated voltage, and relevant standards (such as national standards and industry standards) of the target power equipment. The test voltage is generally about 1.4 times the rated voltage. Since the voltage division ratio of the target voltage divider is known, the standard test voltage value of the low-voltage end of the target voltage divider can be obtained based on the test voltage.

[0040] It should also be noted that the voltage values corresponding to each monitoring time point of the low-voltage end of the target voltage divider during the voltage-rise stage, the full-voltage stage, and the voltage-drop stage are all collected from the voltmeter connected to the low-voltage end of the target voltage divider.

[0041] In the specific embodiments of the present invention, the withstand voltage information includes the thermal-sensitive image on the surface of the equipment, the number of partial discharges, the amount of each partial discharge, and the time point of each partial discharge.

[0042] It should be noted that the thermal-sensitive image on the surface of the equipment is collected by a thermal imager, and the number of partial discharges, the amount of each partial discharge, and the time point of each partial discharge are all collected by a partial discharge detection device.

[0043] The equipment withstand voltage performance evaluation module is used to set the influence factors corresponding to the target power equipment during the withstand voltage test, evaluate whether there are problems with the withstand voltage performance of the target power equipment during the withstand voltage test. If there are problems, it indicates that the target power equipment cannot withstand the voltage and gives feedback. If there are no problems, it indicates that the withstand voltage performance of the target power equipment is intact.

[0044] In a specific embodiment of the present invention, the specific process of setting the influence factor of the withstand voltage test corresponding to the target power equipment in the withstand voltage test is as follows: Based on the voltage values corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the voltage boosting stage, full-voltage stage, and voltage reduction stage, calculate the voltage boosting speed uniformity χ of the low-voltage end of the target voltage divider in the voltage boosting stage 升 , the voltage stability δ corresponding to the full-voltage stage, and the voltage reduction speed uniformity χ of the low-voltage end of the target voltage divider in the voltage reduction stage 降 .

[0045] In a specific embodiment of the present invention, the specific process of calculating the voltage boosting speed uniformity of the low-voltage end of the target voltage divider in the voltage boosting stage is as follows: Denote the voltage values corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the voltage boosting stage as where r represents the number of the monitoring time point, and r = 1, 2,..., q.

[0046] Denote the time interval duration between the monitoring time points in the voltage boosting stage as T.

[0047] Calculate the voltage boosting speed v corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the voltage boosting stage r , where represents the voltage value corresponding to the (r - 1)-th monitoring time point of the low-voltage end of the target voltage divider in the voltage boosting stage.

[0048] Calculate the voltage boosting speed uniformity χ of the low-voltage end of the target voltage divider in the voltage boosting stage 升 , where v r+1 represents the voltage boosting speed corresponding to the (r + 1)-th monitoring time point of the low-voltage end of the target voltage divider in the voltage boosting stage, △v represents the set reference voltage boosting speed deviation, and q represents the number of monitoring time points.

[0049] In a specific embodiment of the present invention, the specific process of calculating the voltage stability of the low-voltage end of the target voltage divider in the full-voltage stage is as follows: Subtract the standard test voltage value corresponding to the low-voltage end of the target voltage divider in the full-voltage stage from the voltage values corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the full-voltage stage to obtain the voltage deviation corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the full-voltage stage, and compare it with the set permitted voltage deviation. If the voltage deviation corresponding to a certain monitoring time point is greater than or equal to the set permitted voltage deviation, then mark this monitoring time point as a pressure deviation time point, and count the number of pressure deviation time points of the low-voltage end of the target voltage divider in the full-voltage stage, and denote it as τ.

[0050] Calculate the voltage stability δ of the low-voltage end of the target voltage divider in the full-voltage stage, Among them, σ represents the proportion of the number of pressure deviation time points set as a reference.

[0051] It should be noted that the specific process of calculating the uniformity of the step-down speed corresponding to the low-voltage end of the target voltage divider in the step-down stage is as follows: Denote the voltage values corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the step-down stage as

[0052] Calculate the step-down speed corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the step-down stage

[0053] Calculate the uniformity χ of the step-down speed corresponding to the low-voltage end of the target voltage divider in the step-down stage 降 , Among them, represents the step-down speed corresponding to the (r + 1)-th monitoring time point of the low-voltage end of the target voltage divider in the step-down stage, and △v′ represents the set reference step-down speed deviation.

[0054] Set the influence factor λ of the withstand voltage test corresponding to the target power equipment in the withstand voltage test, Among them, e represents the natural constant, a1, a2, and a3 respectively represent the proportion weights of the influence factor evaluation of the set step-up speed uniformity, voltage stability, and step-down speed uniformity corresponding to the withstand voltage test, and a1 + a2 + a3 = 1.

[0055] In a specific embodiment of the present invention, the set value of a1 is 0.3, the set value of a2 is 0.4, and the set value of a3 is 0.3. In different stages of the withstand voltage test, these three factors each play a key role. However, from the perspective of the overall evaluation of the test accuracy, the voltage stability in the full-voltage stage may be more important. Because it directly relates to whether the test voltage meets the standard requirements and is the most critical factor for judging whether the power equipment is qualified.

[0056] The embodiment of the present invention deeply analyzes the step-up speed uniformity in the step-up stage, the voltage stability in the full-voltage stage, and the step-down speed uniformity in the step-down stage of the broadband standard voltage divider, thereby setting the influence factor of the withstand voltage test corresponding to the power equipment in the withstand voltage test, accurately obtaining the withstand voltage test data, improving the stability of obtaining the withstand voltage test data, thereby accurately evaluating the withstand voltage ability of the power equipment, and further ensuring the safety of the power equipment in subsequent operation.

[0057] In a specific embodiment of the present invention, the specific process of evaluating whether there is a problem with the withstand voltage performance of the target power equipment in the withstand voltage test is as follows: Based on the surface thermal-sensitive image of the target power equipment corresponding to the withstand voltage test, calculate the equipment heating abnormality index θ of the target power equipment corresponding to the withstand voltage test.

[0058] In a specific embodiment of the present invention, the specific process of calculating the abnormal equipment heating index corresponding to the target power equipment during the withstand voltage test is as follows: Locate the number of temperature distribution regions and the temperature values of each temperature distribution region from the surface thermal image of the equipment corresponding to the target power equipment during the withstand voltage test.

[0059] Record the number of temperature distribution regions corresponding to the target power equipment during the withstand voltage test as ε.

[0060] Compare the temperature values of each temperature distribution region corresponding to the target power equipment during the withstand voltage test with the normal range of the equipment surface temperature. If the temperature values of each temperature distribution region corresponding to the target power equipment during the withstand voltage test are not within the normal range of the equipment surface temperature, then mark this temperature distribution region as a temperature abnormal region, count the number of temperature abnormal regions of the target power equipment during the withstand voltage test, and record it as ε 异 。

[0061] Calculate the abnormal equipment heating index θ corresponding to the target power equipment during the withstand voltage test, where σ1 represents the proportion of the number of temperature abnormal regions set as a reference.

[0062] Based on the number of partial discharges, the amount of each partial discharge, and the time points of each partial discharge corresponding to the target power equipment during the withstand voltage test, calculate the abnormal partial discharge index ω corresponding to the target power equipment during the withstand voltage test.

[0063] It should be noted that the specific process of calculating the abnormal partial discharge index corresponding to the target power equipment during the withstand voltage test is as follows: Record the number of partial discharges corresponding to the target power equipment during the withstand voltage test as μ.

[0064] Extract the maximum discharge amount from the amounts of each partial discharge corresponding to the target power equipment during the withstand voltage test, and record it as Q.

[0065] Compare the time points of each partial discharge corresponding to the target power equipment during the withstand voltage test with each other to obtain the interval duration corresponding to each partial discharge of the target power equipment during the withstand voltage test, and extract the minimum interval duration from it, and record it as T min 。

[0066] Calculate the abnormal partial discharge index ω corresponding to the target power equipment during the withstand voltage test, where μ′, Q′, and T′ respectively represent the set reference number of discharges, discharge amount, and discharge interval duration.

[0067] It should be noted that the number of partial discharges refers to the number of discharge events occurring within a specific time. The maximum discharge amount of partial discharge represents the maximum charge released in a single discharge event. Frequent discharges (i.e., a large number of discharge times) may be accompanied by a relatively large discharge amount, which usually means that there are more defects or more serious deterioration in the equipment insulation. The interval duration between each partial discharge reflects the stability and continuity of the discharge event. A shorter interval duration may mean that the discharge activity is more frequent and unstable, which may cause greater damage to the equipment insulation. The partial discharge anomaly index is a comprehensive index used to evaluate the degree of anomaly of the equipment insulation state. Therefore, the more the number of partial discharges, the greater the maximum discharge amount of partial discharge, and the shorter the interval duration between each partial discharge, the more abnormal the partial discharge and the greater the degree of anomaly of the power equipment insulation state.

[0068] Please refer to Figure 3 as shown, calculate the withstand voltage performance index of the target power equipment in the withstand voltage test Among them, a4 and a5 respectively represent the proportion weights corresponding to the withstand voltage performance evaluation of the set equipment heating anomaly index and partial discharge anomaly index, and a4 + a5 = 1.

[0069] In a specific embodiment of the present invention, the set value of a4 is 0.5, and the set value of a5 is 0.5. The equipment heating anomaly index and partial discharge anomaly index both play extremely important roles in the withstand voltage performance evaluation. In the actual withstand voltage performance evaluation, these two indexes should be used in combination and complement each other to more comprehensively and accurately evaluate the withstand voltage performance of power equipment.

[0070] Compare the withstand voltage performance index of the target power equipment in the withstand voltage test with the set reference withstand voltage performance index. If the withstand voltage performance index of the target power equipment in the withstand voltage test is greater than or equal to the set reference withstand voltage performance index, it indicates that there is no problem with the withstand voltage performance of the target power equipment in the withstand voltage test. Otherwise, it indicates that there is a problem with the withstand voltage performance of the target power equipment in the withstand voltage test.

[0071] The above content is only an example and explanation of the concept of the present invention. Those skilled in the art of this technology make various modifications or supplements to the described specific embodiments or use similar methods to replace them. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they should all belong to the protection scope of the present invention.

Claims

1. A broadband standard voltage divider for the withstand voltage test of power equipment, characterized in that, Including: A voltage division ratio evaluation module under frequency conditions, which is used to record the target broadband standard voltage divider as the target voltage divider, extract the nominal voltage division ratio of the target voltage divider, extract the high voltages output by the standard voltage source to the target voltage divider at each frequency point, collect the low voltages at the low voltage ends corresponding to each output of the target voltage divider at each frequency point, and analyze the accuracy of the voltage division ratio of the target voltage divider at each frequency point; A voltage division ratio evaluation module under temperature conditions, which is used to place the target voltage divider in an environmental chamber with temperature control, extract the high voltage output by the standard voltage source to the target voltage divider, collect the low voltages at the low voltage ends of the target voltage divider at each test temperature, and analyze the accuracy of the voltage division ratio of the target voltage divider at each test temperature; A voltage division ratio accuracy evaluation module, which is used to evaluate whether there is an abnormality in the voltage division ratio accuracy of the target voltage divider. If not, it executes the withstand voltage test information acquisition module. If so, it indicates that the target voltage divider cannot be used for the withstand voltage test of power equipment and gives feedback; A withstand voltage test information acquisition module, which is used to extract the standard test voltage value corresponding to the low voltage end of the target voltage divider during the full voltage stage, collect the voltage values corresponding to each monitoring time point of the low voltage end of the target voltage divider during the voltage rising stage, full voltage stage, and voltage dropping stage, and collect the withstand voltage information corresponding to the target power equipment during the withstand voltage test; An equipment withstand voltage performance evaluation module, which is used to set the withstand voltage test influencing factors corresponding to the target power equipment during the withstand voltage test, evaluate whether there is a problem with the withstand voltage performance of the target power equipment during the withstand voltage test. If there is a problem, it indicates that the target power equipment cannot withstand voltage and gives feedback. If there is no problem, it indicates that the withstand voltage performance of the target power equipment is intact.

2. The broadband standard voltage divider for the withstand voltage test of electrical equipment according to claim 1, wherein: The specific process of analyzing the accuracy of the voltage division ratio of the target voltage divider at each frequency point is as follows: Record the high voltages output by the standard voltage source for each time of the target voltage divider at each frequency point as where i represents the number of the frequency point, i = 1, 2,..., n, and j represents the number of each output, j = 1, 2,..., m; Record the low voltage at the low voltage end corresponding to each output at each frequency point of the target voltage divider as Let the nominal voltage division ratio of the target voltage divider be denoted as K 标 ; Calculate the voltage division ratio accuracy of the target voltage divider at each frequency point Among them, △K represents the voltage division ratio deviation of the set reference, and m represents the number of output times.

3. The broadband standard voltage divider for the withstand voltage test of electrical equipment according to claim 2, characterized in that: The specific process of analyzing the accuracy of the voltage division ratio of the target voltage divider at each test temperature is as follows: Denote the high voltage output by the standard voltage source to the target voltage divider as U 高 ; Denote the low voltage at the low voltage end of the target voltage divider at each test temperature as where g represents the number of the test temperature, g = 1, 2,..., p; Calculate the voltage division ratio accuracy of the target voltage divider at each test temperature 4. A broadband standard voltage divider for the withstand voltage test of power equipment according to claim 3, characterized in that: The specific process of evaluating whether there is an abnormality in the voltage division ratio accuracy of the target voltage divider is as follows: Calculate the voltage division ratio accuracy β of the target voltage divider, where β 频 and β 温 respectively represent the set reference voltage division ratio accuracies at the frequency level and at the test temperature level, n represents the number of frequency points, and p represents the number of test temperatures; Compare the voltage division ratio accuracy of the target voltage divider with the set reference voltage division ratio accuracy. If the voltage division ratio accuracy of the target voltage divider is greater than or equal to the set reference voltage division ratio accuracy, it indicates that there is no abnormality in the voltage division ratio accuracy of the target voltage divider. Otherwise, it indicates that there is an abnormality in the voltage division ratio accuracy of the target voltage divider.

5. A broadband standard voltage divider for the withstand voltage test of electrical equipment according to claim 1, characterized in that: The withstand voltage information includes the surface thermal sensitive image of the equipment, the number of partial discharges, the amount of each partial discharge, and the time point of each partial discharge.

6. A broadband standard voltage divider for the withstand voltage test of electrical equipment according to claim 5, characterized in that: The specific process of setting the withstand voltage test influencing factors corresponding to the target power equipment during the withstand voltage test is as follows: Based on the voltage values corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the boost stage, full-voltage stage, and buck stage, calculate the boost speed uniformity χ corresponding to the low-voltage end of the target voltage divider in the boost stage 升 , the voltage stability δ corresponding to the full-voltage stage, and the buck speed uniformity χ corresponding to the buck stage 降 ; Set the influence factor λ of the withstand voltage test corresponding to the target power equipment during the withstand voltage test. Among them, e represents the natural constant, and a1, a2, and a3 respectively represent the proportion weights of the influence factor evaluation of the set uniform voltage rise rate, voltage stability, and uniform voltage drop rate corresponding to the withstand voltage test, and a1 + a2 + a3 = 1.

7. A broadband standard voltage divider for the withstand voltage test of electrical equipment according to claim 6, characterized in that: The specific process of calculating the uniformity of the voltage rising speed corresponding to the low voltage end of the target voltage divider during the voltage rising stage is as follows: Denote the voltage values corresponding to each monitoring time point during the boosting stage at the low-voltage end of the target voltage divider as where r represents the number of the monitoring time point, and r = 1, 2,..., q; Record the time interval duration between the monitoring time points during the voltage rising stage as T; Calculate the boost rate v corresponding to each monitoring time point at the low-voltage end of the target voltage divider during the boost phase r , where represents the voltage value corresponding to the (r - 1)-th monitoring time point at the low-voltage end of the target voltage divider during the boost phase; Calculate the boost speed uniformity χ corresponding to the low-voltage end of the target voltage divider during the boost phase 升 , where v r+1 represents the boost speed corresponding to the (r + 1)-th monitoring time point of the low-voltage end of the target voltage divider during the boost phase, △v represents the boost speed deviation of the set reference, and q represents the number of monitoring time points.

8. A broadband standard voltage divider for withstand voltage test of power equipment according to claim 7, characterized in that: The specific process of calculating the voltage stability corresponding to the low voltage end of the target voltage divider during the full voltage stage is as follows: Subtract the voltage value corresponding to each monitoring time point of the low-voltage end of the target voltage divider during the full-voltage stage from the standard test voltage value corresponding to the low-voltage end of the target voltage divider during the full-voltage stage to obtain the voltage deviation corresponding to each monitoring time point of the low-voltage end of the target voltage divider during the full-voltage stage, and compare it with the set permissible voltage deviation. If the voltage deviation corresponding to a certain monitoring time point is greater than or equal to the set permissible voltage deviation, then mark this monitoring time point as the pressure deviation time point, count the number of pressure deviation time points of the low-voltage end of the target voltage divider during the full-voltage stage, and denote it as τ; Calculate the voltage stability δ corresponding to the low-voltage end of the target voltage divider during the full-voltage stage. Among them, σ represents the proportion of the number of pressure deviation time points set as a reference.

9. The broadband standard voltage divider for the withstand voltage test of power equipment according to claim 6, characterized in that: The specific process for evaluating whether there is a problem with the withstand voltage performance of the target power equipment during the withstand voltage test is as follows: Based on the surface thermal image of the target power equipment corresponding to the withstand voltage test, calculate the equipment heating anomaly index θ of the target power equipment corresponding to the withstand voltage test; Based on the number of partial discharges, the amount of each partial discharge, and the time point of each partial discharge corresponding to the target power equipment during the withstand voltage test, calculate the partial discharge anomaly index ω of the target power equipment corresponding to the withstand voltage test; Calculate the withstand voltage performance index of the target power equipment during the withstand voltage test Among them, a4 and a5 respectively represent the proportion weights of the withstand voltage performance evaluation corresponding to the set abnormal equipment heating index and partial discharge abnormal index, and a4 + a5 = 1; Compare the withstand voltage performance index of the target power equipment during the withstand voltage test with the set reference withstand voltage performance index. If the withstand voltage performance index of the target power equipment during the withstand voltage test is greater than or equal to the set reference withstand voltage performance index, it indicates that there is no problem with the withstand voltage performance of the target power equipment during the withstand voltage test. Otherwise, it indicates that there is a problem with the withstand voltage performance of the target power equipment during the withstand voltage test.

10. A broadband standard voltage divider for the withstand voltage test of power equipment according to claim 9, characterized in that: The specific process for calculating the equipment heating anomaly index of the target power equipment corresponding to the withstand voltage test is as follows: Locate the number of temperature distribution regions and the temperature values of each temperature distribution region from the surface thermal image of the target power equipment corresponding to the withstand voltage test; Denote the number of temperature distribution regions corresponding to the target power equipment during the withstand voltage test as ε; Compare the temperature values of each temperature distribution area corresponding to the target power equipment during the withstand voltage test with the normal range of the equipment surface temperature. If the temperature values of each temperature distribution area corresponding to the target power equipment during the withstand voltage test are not within the normal range of the equipment surface temperature, then record this temperature distribution area as a temperature abnormal area, count the number of temperature abnormal areas of the target power equipment during the withstand voltage test, and record it as ε 异 ; Calculate the abnormal equipment heating index θ corresponding to the target power equipment during the withstand voltage test. Among them, σ1 represents the proportion of the number of temperature abnormal regions set as a reference.

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