Broadband standard voltage divider for withstand voltage test of power equipment

Abstract

The invention relates to the technical field of broadband standard voltage dividers, and particularly discloses a broadband standard voltage divider for a withstand voltage test of power equipment, which comprises a voltage division ratio evaluation module under a frequency condition, a voltage division ratio evaluation module under a temperature condition, a voltage division ratio accuracy evaluation module, a withstand voltage test information acquisition module and an equipment withstand voltage performance evaluation module. According to the invention, the voltage division ratios of the broadband standard voltage divider under different frequencies, different voltages and different test temperatures are analyzed, and then the boost speed uniformity of the broadband standard voltage divider in the boost stage, the voltage stability of the broadband standard voltage divider in the full-voltage stage and the buck speed uniformity of the broadband standard voltage divider in the buck stage are deeply analyzed; the voltage withstand test influence factors are set, the comprehensiveness and accuracy of voltage division ratio accuracy correction of the broadband standard voltage divider are improved, and the stability of voltage withstand test data acquisition is improved, so that the voltage withstand capability of the power equipment is accurately evaluated, and the safety of the power equipment in subsequent operation is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of wide-band standard voltage dividers, and in particular to a wide-band standard voltage divider for a withstand voltage test of electric 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 capability of power equipment, a wide-band standard voltage divider is required for voltage measurement and monitoring. Traditional voltage dividers have problems such as unstable voltage divider ratio and susceptibility to environmental interference within a wide frequency range, and cannot meet the requirements of high-precision withstand voltage tests. Therefore, a wide-band standard voltage divider is required when conducting withstand voltage tests on power equipment.

[0003] For example, the Chinese patent publication number CN115542231A discloses a wideband calibration instrument inspection device based on a standard source, including: a wideband standard source generator, which is used to output voltage and current standard signals with adjustable amplitudes at different frequencies. A wideband voltage and current reference signal acquisition module, which is used to obtain the voltage and current standard signals output by the wideband standard source generator, and use the voltage and current standard signals as wideband voltage and current reference signals. A wideband difference voltage and current signal acquisition module, which is used to divide the wideband voltage reference signal to obtain a wideband voltage in-phase component, and obtain a wideband voltage orthogonal component through an orthogonal waveform generator. The wideband voltage in-phase component and the wideband voltage orthogonal component are synthesized into a wideband voltage difference signal. A wideband current difference signal is obtained by converting the wideband voltage difference signal. A verification module, which uses the wideband voltage and current reference signal and the wideband voltage and current difference signal to verify and calibrate the wideband calibration instrument. The problem of being unable to carry out wideband overall verification is solved.

[0004] For example, the Chinese patent publication number CN205139353U discloses an automatic calibration device for an AC voltage divider, including: an industrial computer system, a broadband high-stable power supply, a medium-frequency step-up transformer, and a standard broadband voltage divider connected in sequence, wherein the standard broadband voltage divider is used to be connected in parallel with the AC voltage divider to be tested. The industrial computer system is used to send a control signal to control the frequency and amplitude of the output voltage of the broadband high-stable power supply according to a preset voltage detection point, perform voltage sampling on 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, and automatically stop boosting when the voltage at the high-voltage end of the standard broadband voltage divider reaches a preset voltage detection point. The medium-frequency step-up transformer is used to boost the output voltage of the broadband high-stable 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, small frequency deviation, and can avoid changes in the readings of the resistive-capacitive voltage divider caused by voltage quality problems. The entire detection and calibration process is fully automatic, and can avoid operating errors in the manual voltage regulation or mechanical voltage regulation process.

[0005] The above existing technologies still have the following problems in the withstand voltage test of power equipment: 1. Only the voltage dividing ratio of the wide-band standard voltage divider at different frequencies and voltage amplitudes is corrected, and the accuracy of the voltage dividing ratio of the wide-band standard voltage divider at different test temperatures is not deeply analyzed, which reduces the comprehensiveness and accuracy of the voltage dividing ratio accuracy correction of the wide-band standard voltage divider, and cannot provide reliable test data for subsequent withstand voltage performance tests of power equipment, thereby reducing the reliability of the withstand voltage performance analysis of power equipment.

[0006] 2. No in-depth analysis was conducted on the voltage changes of the wide-band standard voltage divider in the boost stage, full-voltage stage and step-down stage. In other words, in the voltage withstand test of the power equipment, the impact of the voltage conditions of the wide-band standard voltage divider in different working stages on the voltage withstand performance was not analyzed. As a result, the voltage withstand test data could not be accurately obtained, which reduced the stability of the voltage withstand test data acquisition, making it impossible to accurately evaluate the voltage withstand capacity of the power equipment, and further unable to ensure the safety of the power equipment in subsequent operation. Summary of the invention

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

[0008] The purpose of the present invention can be achieved through the following technical solutions: The present invention provides a wide-band standard voltage divider for a withstand voltage test of an electric power device, comprising: a voltage divider ratio evaluation module under frequency conditions, which is used to record a target wide-band standard voltage divider as a target voltage divider, extract the nominal voltage divider ratio of the target voltage divider, extract the high voltage outputted 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 corresponding to the target voltage divider at each frequency point, and analyze the voltage divider ratio accuracy of the target voltage divider at each frequency point.

[0009] The voltage divider ratio evaluation module under temperature conditions is used to place the target voltage divider in a temperature-controlled environmental chamber, extract the high voltage output of 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 divider ratio accuracy of the target voltage divider at each test temperature.

[0010] The voltage divider ratio accuracy evaluation module is used to evaluate whether there is any abnormality in the voltage divider 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 the power equipment, and feedback is given.

[0011] The voltage withstand test information acquisition module is used to extract the standard test voltage value corresponding to the low-voltage end of the target voltage divider in the full-voltage stage, collect the voltage values ​​corresponding to each monitoring time point in the boost stage, the full-voltage stage and the step-down stage of the low-voltage end of the target voltage divider, and collect the voltage withstand information corresponding to the target power equipment in the voltage withstand test.

[0012] The equipment voltage withstand performance evaluation module is used to set the corresponding voltage withstand test influencing factor of the target power equipment in the voltage withstand test, and evaluate whether there is a problem with the voltage withstand performance of the target power equipment in the voltage withstand test. If there is a problem, it indicates that the target power equipment is not voltage-resistant and feedback is given. If there is no problem, it indicates that the voltage withstand performance of the target power equipment is intact.

[0013] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: (1) The present invention analyzes the voltage divider ratio of the wide-band standard voltage divider at different frequencies and voltage amplitudes and at different test temperatures to evaluate whether there is any abnormality in the voltage divider ratio accuracy of the voltage divider, thereby improving the comprehensiveness and accuracy of the voltage divider ratio accuracy correction of the wide-band standard voltage divider, providing reliable test data for subsequent voltage withstand performance tests of power equipment, thereby improving the reliability of the voltage withstand performance analysis of power equipment.

[0014] (2) The present invention conducts an in-depth analysis of the uniformity of the boost speed in the boost stage, the voltage stability in the full voltage stage, and the uniformity of the step-down speed in the step-down stage of the wide-band standard voltage divider, thereby setting the corresponding voltage withstand test influencing factors of the power equipment in the voltage withstand test, accurately acquiring the voltage withstand test data, and improving the stability of the voltage withstand test data acquisition, thereby accurately evaluating the voltage withstand capability of the power equipment, and further ensuring the safety of the power equipment in subsequent operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

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

[0017] Figure 2 FIG. 4 is a flow chart of evaluating the accuracy of the voltage divider ratio of the target voltage divider of the present invention.

[0018] Figure 3 The figure is a flow chart of the voltage withstand performance evaluation of the electric power equipment of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] See also Figure 1 As shown, the present invention provides a wide-band standard voltage divider for a withstand voltage test of electric power equipment, comprising: a voltage divider ratio evaluation module under frequency conditions, a voltage divider ratio evaluation module under temperature conditions, a voltage divider ratio accuracy evaluation module, a withstand voltage test information acquisition module and an equipment withstand voltage performance evaluation module.

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

[0022] The voltage divider ratio evaluation module under the frequency condition is used to record the target wide-band standard voltage divider as the target voltage divider, extract the nominal voltage divider ratio of the target voltage divider, extract the high voltage outputted 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 divider 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, and the low voltage at the low-voltage end of the target voltage divider corresponding to each output at each frequency point is collected from a 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 divider ratio accuracy of the target voltage divider at each frequency point is as follows: the high voltage output of the standard voltage source to the target voltage divider at each frequency point is recorded as Wherein, 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] The low voltage at the low voltage end of the target voltage divider corresponding to each output at each frequency point is recorded as

[0027] The nominal voltage divider ratio of the target voltage divider is recorded as K 标 .

[0028] Calculate the voltage divider ratio accuracy of the target voltage divider at each frequency point Among them, △K represents the voltage divider ratio deviation of the set reference, and m represents the number of outputs.

[0029] The voltage divider ratio evaluation module under the temperature condition is used to place the target voltage divider in a temperature-controlled environmental chamber, 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 divider 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 divider ratio accuracy of the target voltage divider at each test temperature is as follows: the high voltage output by the standard voltage source to the target voltage divider is recorded as U 高 .

[0032] The low pressure at the low pressure end of the target voltage divider at each test temperature is recorded as Wherein, g represents the number of the test temperature, g = 1, 2, ..., p.

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

[0034] The voltage divider accuracy evaluation module is used to evaluate whether there is an abnormality in the voltage divider 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 the power equipment, and feedback is provided.

[0035] See also 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 divider ratio accuracy of the target voltage divider is: calculating the voltage divider ratio accuracy β of the target voltage divider, Among them, β 频 and β 温 They represent the accuracy of the reference voltage divider ratio set at the frequency level and at the test temperature level, respectively. n represents the number of frequency points, and p represents the number of test temperatures.

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

[0037] The embodiment of the present invention analyzes the voltage division ratio of the wide-band standard voltage divider at different frequencies and voltage amplitudes and at different test temperatures, evaluates whether there is an abnormality in the voltage division ratio accuracy of the voltage divider, improves the comprehensiveness and accuracy of the voltage division ratio accuracy correction of the wide-band standard voltage divider, provides reliable test data for subsequent voltage withstand performance tests of power equipment, and thus improves the reliability of the voltage withstand performance analysis of power equipment.

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

[0039] It should be noted that the method for confirming the standard test voltage value corresponding to the low-voltage end of the target voltage divider in the full-voltage stage is: determine the test voltage according to the type, rated voltage and relevant standards (such as national standards, industry standards) of the target power equipment. The test voltage is generally about 1.4 times the rated voltage. Since the voltage divider 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 according to the test voltage.

[0040] It should also be noted that the voltage values ​​corresponding to each monitoring time point at the low voltage end of the target voltage divider in the boost stage, the full voltage stage and the buck stage are all collected from a voltmeter connected to the low voltage end of the target voltage divider.

[0041] In a specific embodiment of the present invention, the withstand voltage information includes a thermal image of the device surface, 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 image of the device surface is acquired 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 acquired by a partial discharge detection device.

[0043] The equipment voltage withstand performance evaluation module is used to set the voltage withstand test influencing factor corresponding to the target power equipment in the voltage withstand test, and evaluate whether there is a problem with the voltage withstand performance of the target power equipment in the voltage withstand test. If there is a problem, it indicates that the target power equipment is not voltage-resistant, and feedback is provided. If there is no problem, it indicates that the voltage withstand performance of the target power equipment is intact.

[0044] In a specific embodiment of the present invention, the specific process of setting the corresponding voltage test influencing factor of the target power equipment in the voltage test is: based on the voltage values ​​corresponding to each monitoring time point in the boost stage, the full voltage stage and the buck stage of the low-voltage end of the target voltage divider, respectively calculate the boost speed uniformity x 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 voltage reduction speed uniformity χ corresponding to the voltage reduction stage 降 .

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

[0046] The time interval between monitoring time points in the boost phase is recorded as T.

[0047] Calculate the boost speed v corresponding to each monitoring time point at the low voltage end of the target voltage divider during the boost phase r , in, It represents the voltage value of the low voltage end of the target voltage divider corresponding to the r-1th monitoring time point in the boost phase.

[0048] Calculate the boost speed uniformity χ corresponding to the low-voltage end of the target voltage divider during the boost phase 升 , Among them, v r+1 It represents the boost speed corresponding to the r+1th monitoring time point at the low-voltage end of the target voltage divider in the boost phase, △v represents the boost speed deviation of the set reference, 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 corresponding to the low-voltage end of the target voltage divider in the full-voltage stage is: subtract the voltage value corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the full-voltage stage from the standard test voltage value corresponding to the low-voltage end of the target voltage divider in the full-voltage stage, and 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 monitoring time point is greater than or equal to the set permitted voltage deviation, then the monitoring time point is recorded as a pressure deviation time point, and the number of pressure deviation time points of the low-voltage end of the target voltage divider in the full-voltage stage is counted and recorded as τ.

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

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

[0052] Calculate the voltage reduction speed of the low voltage end of the target voltage divider at each monitoring time point during the voltage reduction phase

[0053] Calculate the voltage reduction speed uniformity χ corresponding to the low-voltage end of the target voltage divider during the voltage reduction stage 降 , in, It represents the voltage reduction speed corresponding to the r+1th monitoring time point at the low-voltage end of the target voltage divider in the voltage reduction stage, and △v′ represents the voltage reduction speed deviation of the set reference.

[0054] Set the corresponding voltage test influence factor λ of the target power equipment in the voltage test, Wherein, e represents a natural constant, a1, a2 and a3 represent the weights of the assessment of the influence factors of the withstand voltage test corresponding to the set uniformity of the boost speed, voltage stability and uniformity of the buck speed, respectively, and a1+a2+a3=1.

[0055] In the specific embodiment of the present invention, the setting value of a1 is 0.3, the setting value of a2 is 0.4, and the setting value of a3 is 0.3. In different stages of the withstand voltage test, these three factors each have their key roles. However, from the perspective of the overall test accuracy assessment, the voltage stability at the full voltage stage may be more important. Because it is directly related to whether the test voltage meets the standard requirements, it is the most critical factor in judging whether the power equipment is qualified.

[0056] The embodiment of the present invention conducts in-depth analysis on the boost speed uniformity of the wide-band standard voltage divider in the boost stage, the voltage stability in the full voltage stage, and the step-down speed uniformity in the step-down stage, thereby setting the corresponding voltage withstand test influencing factors of the power equipment in the voltage withstand test, accurately acquiring the voltage withstand test data, and improving the stability of the voltage withstand test data acquisition, thereby accurately evaluating the voltage withstand capability 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 voltage withstand performance of the target power equipment in the voltage withstand test is: based on the device surface thermal sensitive image corresponding to the target power equipment in the voltage withstand test, the device heating abnormality index θ corresponding to the target power equipment in the voltage withstand test is calculated.

[0058] In a specific embodiment of the present invention, the specific process of calculating the equipment heating anomaly index corresponding to the target power equipment in the voltage withstand test is: locating the number of temperature distribution areas and the temperature value of each temperature distribution area from the equipment surface thermal image corresponding to the target power equipment in the voltage withstand test.

[0059] The number of temperature distribution areas corresponding to the target power equipment in the withstand voltage test is recorded as ε.

[0060] The temperature values ​​of each temperature distribution area corresponding to the target power equipment in the withstand voltage test are compared with the normal range of the equipment surface temperature. If the temperature values ​​of each temperature distribution area corresponding to the target power equipment in the withstand voltage test are not within the normal range of the equipment surface temperature, the temperature distribution area is recorded as an abnormal temperature area. The number of abnormal temperature areas of the target power equipment in the withstand voltage test is counted and recorded as ε 异 .

[0061] Calculate the equipment heating abnormality index θ corresponding to the target power equipment in the voltage withstand test, Among them, σ1 represents the proportion of temperature anomaly areas set as reference.

[0062] 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 in the withstand voltage test, the partial discharge abnormality index ω corresponding to the target power equipment in the withstand voltage test is calculated.

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

[0064] The maximum discharge amount is extracted from the corresponding partial discharge amounts of the target power equipment in the withstand voltage test and recorded as Q.

[0065] The time points of each partial discharge of the target power equipment in the withstand voltage test are compared with each other to obtain the interval time corresponding to each partial discharge of the target power equipment in the withstand voltage test, and the minimum interval time is extracted from them, which is recorded as T min .

[0066] Calculate the partial discharge anomaly index ω corresponding to the target power equipment in the withstand voltage test, Wherein, μ′, Q′ and T′ represent the discharge times, discharge amount and discharge interval duration of the set reference respectively.

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

[0068] See also Figure 3 As shown, the withstand voltage performance index of the target power equipment in the withstand voltage test is calculated Among them, a4 and a5 represent the weights of the set equipment heating abnormality index and partial discharge abnormality index corresponding to the withstand voltage performance evaluation, a4+a5=1.

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

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

[0071] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they shall all fall within the protection scope of the present invention.

Claims

1. A wide-band standard voltage divider for withstand voltage test of electric power equipment, characterized in that: include: The voltage divider ratio evaluation module under frequency conditions is used to record the target wideband standard voltage divider as the target voltage divider, extract the nominal voltage divider ratio of the target voltage divider, extract the high voltage output of 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 divider ratio accuracy of the target voltage divider at each frequency point; The voltage divider ratio evaluation module under temperature conditions is used to place the target voltage divider in a temperature-controlled environmental chamber, extract the high voltage output of 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 divider ratio accuracy of the target voltage divider at each test temperature; The voltage divider accuracy evaluation module is used to evaluate whether there is an abnormality in the voltage divider accuracy of the target voltage divider. If not, the withstand voltage test information acquisition module is executed. If so, it indicates that the target voltage divider cannot be used for the withstand voltage test of the power equipment, and feedback is given; 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 in the full-voltage stage, collect the voltage values ​​corresponding to each monitoring time point in the boost stage, the full-voltage stage and the step-down stage of the low-voltage end of the target voltage divider, and collect the withstand voltage information corresponding to the target power equipment in the withstand voltage test; The equipment voltage withstand performance evaluation module is used to set the corresponding voltage withstand test influencing factor of the target power equipment in the voltage withstand test, and evaluate whether there is a problem with the voltage withstand performance of the target power equipment in the voltage withstand test. If there is a problem, it indicates that the target power equipment is not voltage-resistant and feedback is given. If there is no problem, it indicates that the voltage withstand performance of the target power equipment is intact.

2. A wide-band standard voltage divider for withstand voltage test of electric power equipment according to claim 1, characterized in that: The specific process of analyzing the voltage divider ratio accuracy of the target voltage divider at each frequency point is as follows: The high voltage output of the standard voltage source to the target voltage divider at each frequency point is recorded as Wherein, i represents the number of the frequency point, i=1,2,...,n, j represents the number of each output, j=1,2,...,m; The low voltage at the low voltage end of the target voltage divider corresponding to each output at each frequency point is recorded as The nominal voltage divider ratio of the target voltage divider is recorded as K 标 ; Calculate the voltage divider ratio accuracy of the target voltage divider at each frequency point Among them, △K represents the voltage divider ratio deviation of the set reference, and m represents the number of outputs.

3. A wide-band standard voltage divider for withstand voltage test of electric power equipment according to claim 2, characterized in that: The specific process of analyzing the voltage divider ratio accuracy of the target voltage divider at each test temperature is as follows: The high voltage output of the standard voltage source to the target voltage divider is recorded as U 高 ; The low pressure at the low pressure end of the target voltage divider at each test temperature is recorded as Wherein, g represents the number of the test temperature, g = 1, 2, ..., p; Calculate the voltage divider ratio accuracy of the target voltage divider at each test temperature 4. A wide-band standard voltage divider for withstand voltage test of electric power equipment according to claim 3, characterized in that: The specific process of evaluating whether the voltage divider ratio accuracy of the target voltage divider is abnormal is as follows: Calculate the voltage divider ratio accuracy β of the target voltage divider, Among them, β 频 and β 温 They represent the accuracy of the reference voltage divider ratio set at the frequency level and at the test temperature level, respectively. n represents the number of frequency points, and p represents the number of test temperatures. The voltage divider ratio accuracy of the target voltage divider is compared with the voltage divider ratio accuracy of the set reference. If the voltage divider ratio accuracy of the target voltage divider is greater than or equal to the voltage divider ratio accuracy of the set reference, it indicates that there is no abnormality in the voltage divider ratio accuracy of the target voltage divider. Otherwise, it indicates that there is an abnormality in the voltage divider ratio accuracy of the target voltage divider.

5. The wide-band standard voltage divider for withstand voltage test of electric power equipment according to claim 1, characterized in that: The withstand voltage information includes a thermal image of the device surface, the number of partial discharges, the amount of each partial discharge, and the time point of each partial discharge.

6. A wide-band standard voltage divider for withstand voltage test of electric power equipment according to claim 5, characterized in that: The specific process of setting the corresponding voltage test influencing factor of the target power equipment in the 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, the full-voltage stage, and the buck stage, the boost speed uniformity χ corresponding to the low-voltage end of the target voltage divider in the boost stage is calculated respectively. 升 , the voltage stability δ corresponding to the full voltage stage and the voltage reduction speed uniformity χ corresponding to the voltage reduction stage 降 ; Set the corresponding voltage test influence factor λ of the target power equipment in the voltage test, Wherein, e represents a natural constant, a1, a2 and a3 represent the weights of the assessment of the influence factors of the withstand voltage test corresponding to the set uniformity of the boost speed, voltage stability and uniformity of the buck speed, respectively, and a1+a2+a3=1.

7. A wide-band standard voltage divider for withstand voltage test of electric power equipment according to claim 6, characterized in that: The specific process of calculating the boost speed uniformity corresponding to the low-voltage end of the target voltage divider during the boost stage is as follows: The voltage value corresponding to each monitoring time point at the low voltage end of the target voltage divider during the boost phase is recorded as Wherein, r represents the number of the monitoring time point, r = 1, 2, ..., q; The time interval between monitoring time points in the boost phase is recorded as T; Calculate the boost speed v corresponding to each monitoring time point at the low voltage end of the target voltage divider during the boost phase r , in, Indicates the voltage value of the low voltage end of the target voltage divider corresponding to the r-1th monitoring time point in 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 , Among them, v r+1 It represents the boost speed corresponding to the r+1th monitoring time point at the low-voltage end of the target voltage divider in the boost phase, △v represents the boost speed deviation of the set reference, and q represents the number of monitoring time points.

8. A wide-band standard voltage divider for withstand voltage test of electric 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 in the full-voltage stage is: Subtract the voltage value corresponding to each monitoring time point of the low-voltage end of the target voltage divider in the full-voltage stage from the standard test voltage value corresponding to the low-voltage end of the target voltage divider in the full-voltage stage, and 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 the monitoring time point is recorded as the pressure deviation time point, and the number of pressure deviation time points of the low-voltage end of the target voltage divider in the full-voltage stage is counted and recorded as τ; Calculate the voltage stability δ of the low voltage end of the target voltage divider at the full voltage stage. Among them, σ represents the ratio of the number of pressure deviation time points of the set reference.

9. A wide-band standard voltage divider for withstand voltage test of electric power equipment according to claim 6, characterized in that: 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 device surface thermal image corresponding to the target power device in the voltage withstand test, the device heating abnormality index θ corresponding to the target power device in the voltage withstand test is calculated; 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 in the withstand voltage test, the partial discharge abnormality index ω corresponding to the target power equipment in the withstand voltage test is calculated; Calculate the withstand voltage performance index of the target power equipment in the withstand voltage test Among them, a4 and a5 represent the weights of the set equipment heating abnormality index and partial discharge abnormality index corresponding to the withstand voltage performance evaluation, a4+a5=1; The voltage withstand performance index of the target power equipment in the voltage withstand test is compared with the set reference voltage withstand performance index. If the voltage withstand performance index of the target power equipment in the voltage withstand test is greater than or equal to the set reference voltage withstand performance index, it indicates that there is no problem with the voltage withstand performance of the target power equipment in the voltage withstand test; otherwise, it indicates that there is a problem with the voltage withstand performance of the target power equipment in the voltage withstand test.

10. A wide-band standard voltage divider for withstand voltage test of electric power equipment according to claim 9, characterized in that: The specific process of calculating the equipment heating abnormality index corresponding to the target power equipment in the voltage withstand test is as follows: Locate the number of temperature distribution areas and the temperature value of each temperature distribution area from the thermal image of the equipment surface corresponding to the target power equipment in the withstand voltage test; The number of temperature distribution areas corresponding to the target power equipment in the withstand voltage test is recorded as ε; The temperature values ​​of each temperature distribution area corresponding to the target power equipment in the withstand voltage test are compared with the normal range of the equipment surface temperature. If the temperature values ​​of each temperature distribution area corresponding to the target power equipment in the withstand voltage test are not within the normal range of the equipment surface temperature, the temperature distribution area is recorded as an abnormal temperature area. The number of abnormal temperature areas of the target power equipment in the withstand voltage test is counted and recorded as ε 异 ; Calculate the equipment heating abnormality index θ corresponding to the target power equipment in the voltage withstand test, Among them, σ1 represents the proportion of temperature anomaly areas set as reference.

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