A method and system for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave.

Abstract

This invention discloses a method and system for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves, relating to the field of insulation withstand voltage index calculation technology. The method involves obtaining an initial epoxy material sample and performing pre-processing on the sample to obtain a target epoxy material sample. Partial discharge detection is then performed on the target sample to obtain the partial discharge initiation voltage. Based on various preset external operating parameters, the insulation withstand voltage of the target epoxy material is tested using the partial discharge initiation voltage to obtain withstand voltage data corresponding to each external operating parameter. High-frequency withstand voltage analysis is then performed on each withstand voltage data to obtain the insulation withstand voltage index corresponding to the initial epoxy material sample. This invention addresses the technical problem that while the constant stress method can be used to obtain the withstand voltage index of epoxy material by acquiring the insulation failure time under different constant electric fields, it does not fully consider the influence of high-frequency square waves on the epoxy material, leading to inaccurate calculation results for the withstand voltage index of epoxy material under high-frequency square waves.

Description

Technical Field

[0001] This invention relates to the field of insulation withstand voltage index calculation technology, and in particular to a method and system for calculating the insulation withstand voltage index of epoxy resin under high frequency square wave. Background Technology

[0002] Epoxy resin, as one of the most important insulating materials, belongs to the 3D network structure and has permanent covalent cross-linking bonds. This material has high mechanical strength, dimensional stability, and resistance to high temperatures and chemical corrosion. It has wide applications in the field of power electronics. However, with the continuous increase in voltage levels and power of power electronic equipment, high-frequency power electronic devices need to withstand transient bipolar square waves from the front and rear stages of DC-DC converters. In addition, the presence of stray parameters such as leakage inductance and distributed capacitance of high-frequency transformers means that the epoxy materials of high-frequency power electronic devices are subjected to high-repetition-frequency electrical stress impacts for a long time, which greatly increases the probability of breakdown and surface flashover. Therefore, studying the withstand voltage index of epoxy materials under high-frequency square waves is of great significance for the optimized design of epoxy material structures in high-frequency power electronic devices.

[0003] Currently, the constant stress method can be used to obtain the withstand voltage index of epoxy materials by acquiring the insulation failure time under different constant electric fields. However, the influence of high-frequency square waves on epoxy materials is not fully considered, resulting in inaccurate calculation results of the withstand voltage index of epoxy materials under high-frequency square waves. Summary of the Invention

[0004] This invention provides a method and system for calculating the withstand voltage index of epoxy resin insulation under high-frequency square waves. It solves the technical problem that while the withstand voltage index of epoxy materials can be obtained by fitting the insulation failure time under different constant electric fields using the constant stress method, the influence of high-frequency square waves on epoxy materials is not fully considered, resulting in inaccurate calculation results of the withstand voltage index of epoxy materials under high-frequency square waves.

[0005] The first aspect of this invention provides a method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave conditions, comprising:

[0006] An initial epoxy material sample is obtained, and the initial epoxy material sample is subjected to detection pretreatment to obtain the target epoxy material sample.

[0007] Partial discharge detection was performed on the target epoxy material sample to obtain the partial discharge initiation voltage.

[0008] According to a variety of preset external operating condition parameters, the partial discharge initiation voltage is used to perform insulation withstand voltage testing on the target epoxy material to obtain withstand voltage data corresponding to various external operating condition parameters;

[0009] High-frequency withstand voltage analysis was performed on each of the withstand voltage data to obtain the insulation withstand voltage index corresponding to the initial epoxy material sample.

[0010] Optionally, the step of performing a pretreatment on the initial epoxy material sample to obtain the target epoxy material sample includes:

[0011] A pre-set curing agent and accelerator are added to the initial epoxy material sample to generate a first epoxy material sample;

[0012] The first epoxy material sample was degassed to obtain the second epoxy material sample.

[0013] The second epoxy material sample was cured to obtain the target epoxy material sample.

[0014] Optionally, the step of performing partial discharge detection on the target epoxy material sample to obtain the partial discharge initiation voltage includes:

[0015] Partial discharge tests were performed on the target epoxy material sample using a linear boost method to obtain partial discharge data.

[0016] Fourier spectrum analysis was performed on the partial discharge data to obtain multiple partial discharge spectrum values;

[0017] Each partial discharge spectrum value is determined to be greater than a preset partial discharge frequency threshold.

[0018] When the partial discharge spectrum value is greater than the partial discharge frequency threshold, the partial discharge spectrum value is determined as the target spectrum value.

[0019] The minimum value among the test voltages associated with each of the target spectrum values ​​is selected as the partial discharge initiation voltage.

[0020] Optionally, the step of performing high-frequency withstand voltage analysis on each of the withstand voltage data to obtain the insulation withstand voltage index corresponding to the initial epoxy material sample includes:

[0021] Each of the pressure resistance data is input into a preset pressure resistance index function to obtain the initial pressure resistance index corresponding to each of the pressure resistance data.

[0022] Each withstand voltage data and the initial withstand voltage index corresponding to each withstand voltage data are input into a preset inverse power function to obtain the predicted insulation life data corresponding to each withstand voltage data.

[0023] Based on the predicted insulation life data, the goodness of fit of all the withstand voltage data is evaluated to obtain the goodness of fit value corresponding to each withstand voltage data.

[0024] The maximum value of each of the goodness-of-fit values ​​is selected as the target goodness-of-fit value, and the initial withstand voltage index associated with the target goodness-of-fit value is used as the insulation withstand voltage index corresponding to the initial epoxy material sample.

[0025] Optionally, the step of evaluating the goodness of fit of all the withstand voltage data based on each of the predicted insulation life data to obtain the goodness of fit value corresponding to each of the withstand voltage data includes:

[0026] The actual insulation life in each of the withstand voltage data is averaged to obtain the first average value corresponding to each withstand voltage data.

[0027] The actual insulation life in each of the withstand voltage data is compared with the associated first mean value to obtain the first difference value corresponding to each of the withstand voltage data.

[0028] The predicted insulation life in each of the predicted insulation life data is compared with the associated first mean to obtain the second difference value corresponding to each of the predicted insulation life data.

[0029] The first difference corresponding to each of the aforementioned pressure resistance data is summed by squares to obtain the first sum of squares corresponding to each of the aforementioned pressure resistance data.

[0030] The second difference corresponding to each of the predicted insulation life data is summed by squares to obtain the second sum of squares corresponding to each of the predicted insulation life data.

[0031] The first sum of squares and the second sum of squares corresponding to each of the pressure resistance data are compared to obtain the goodness-of-fit value corresponding to each of the pressure resistance data.

[0032] Optionally, the external operating parameters include frequency parameters, temperature parameters, and voltage parameters.

[0033] The second aspect of this invention provides a system for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave conditions, comprising:

[0034] The pretreatment module is used to obtain an initial epoxy material sample and perform detection pretreatment on the initial epoxy material sample to obtain a target epoxy material sample.

[0035] The partial discharge detection module is used to perform partial discharge detection on the target epoxy material sample to obtain the partial discharge initiation voltage.

[0036] The withstand voltage testing module is used to perform insulation withstand voltage testing on the target epoxy material according to a variety of preset external operating condition parameters and the partial discharge initiation voltage, so as to obtain withstand voltage data corresponding to various external operating condition parameters.

[0037] The withstand voltage analysis module is used to perform high-frequency withstand voltage analysis on each of the withstand voltage data to obtain the insulation withstand voltage index corresponding to the initial epoxy material sample.

[0038] A third aspect of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method for calculating the withstand voltage index of epoxy resin insulation under high frequency square wave as described in any of the preceding claims.

[0039] The fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, it implements the method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave as described in any of the preceding claims.

[0040] The fifth aspect of the present invention provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, wherein, when the program instructions are executed by a computer, the computer performs the method for calculating the epoxy resin insulation withstand voltage index under high-frequency square wave as described in any of the preceding claims.

[0041] As can be seen from the above technical solutions, the present invention has the following advantages:

[0042] By performing insulation withstand voltage tests on the target epoxy material according to various preset external operating parameters and partial discharge initiation voltage, withstand voltage data corresponding to various external operating parameters are obtained. The insulation withstand voltage index of the epoxy resin under high-frequency square waves can then be obtained by fitting these withstand voltage data. This overcomes the technical problem of using the constant stress method, which obtains the withstand voltage index of epoxy materials by acquiring the insulation failure time under different constant electric fields, but does not fully consider the influence of high-frequency square waves on the epoxy material, leading to inaccurate calculation results for the withstand voltage index of epoxy materials under high-frequency square waves. Compared with traditional withstand voltage index calculation methods, this invention performs insulation withstand voltage tests on the target epoxy material according to various preset external operating parameters and partial discharge initiation voltage, obtaining multiple withstand voltage data. This directly reflects the influence of high-frequency square waves on epoxy materials, improving the accuracy of the calculated withstand voltage index of epoxy materials under high-frequency square waves. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 The flowchart illustrates the steps of a method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave, as provided in Embodiment 1 of the present invention.

[0045] Figure 2 The flowchart illustrates the steps of a method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave conditions, as provided in Embodiment 2 of the present invention.

[0046] Figure 3 This is a schematic diagram of the partial discharge and insulation life testing platform structure provided in Embodiment 2 of the present invention;

[0047] Figure 4 This is a schematic diagram of data fitting for the effect of voltage on epoxy resin provided in Embodiment 2 of the present invention;

[0048] Figure 5 This is a schematic diagram of data fitting for the effect of frequency on epoxy resin provided in Embodiment 2 of the present invention;

[0049] Figure 6 This is a structural block diagram of a system for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave, provided in Embodiment 3 of the present invention.

[0050] Figure 7 This is a structural block diagram of an electronic device provided in Embodiment 4 of the present invention;

[0051] exist Figure 3 middle:

[0052] 1. PC terminal; 2. Bandwidth digital oscilloscope; 3. High-pass filter; 4. UHF sensor; 5. Plate electrode; 6. Insulation resistor; 7. High voltage probe; 8. Bipolar square wave voltage source. Detailed Implementation

[0053] This invention provides a method and system for calculating the withstand voltage index of epoxy resin insulation under high-frequency square waves. It addresses the technical problem that while the constant stress method can be used to obtain the withstand voltage index of epoxy materials by acquiring the insulation failure time under different constant electric fields, it does not fully consider the influence of high-frequency square waves on epoxy materials, resulting in inaccurate calculation results of the withstand voltage index of epoxy materials under high-frequency square waves.

[0054] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0055] Please see Figure 1 , Figure 1 The flowchart illustrates the steps of a method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave conditions, as provided in Embodiment 1 of the present invention.

[0056] This invention provides a method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave conditions, comprising:

[0057] Step 101: Obtain an initial epoxy material sample and perform a detection pretreatment on the initial epoxy material sample to obtain the target epoxy material sample.

[0058] The initial epoxy material sample refers to the epoxy matrix of the epoxy resin.

[0059] The target epoxy material sample refers to a 0.1 mm epoxy resin sample.

[0060] In this embodiment of the invention, an initial epoxy material sample is obtained, and the initial epoxy material sample is subjected to detection pretreatment to obtain a 0.1 mm epoxy resin sample.

[0061] Step 102: Perform partial discharge detection on the target epoxy material sample to obtain the partial discharge initiation voltage;

[0062] Partial discharge initiation voltage refers to the partial discharge initiation voltage of the target epoxy material sample.

[0063] In this embodiment of the invention, a linear boost method is used to detect partial discharge of the target epoxy material through a preset partial discharge test platform to obtain the partial discharge initiation voltage corresponding to the target epoxy material.

[0064] In another embodiment, the PDIV measurement method is used to detect partial discharge of the target epoxy material to obtain the partial discharge initiation voltage corresponding to the target epoxy material.

[0065] It should be noted that the PDIV measurement method is as follows: PDIV is measured by using a linear boost method. When a partial discharge signal first appears, the voltage applied by the power supply at this time is the PDIV.

[0066] Step 103: According to the preset external operating condition parameters, the insulation withstand voltage of the target epoxy material is tested using the partial discharge initiation voltage to obtain the withstand voltage data corresponding to various external operating condition parameters;

[0067] External operating parameters refer to the variable parameters that affect the pressure resistance characteristics of epoxy resin, including but not limited to frequency parameters, voltage parameters, and temperature parameters.

[0068] Withstand voltage data refers to the insulation life obtained when the target epoxy material is subjected to insulation withstand voltage testing under external operating conditions.

[0069] In this embodiment of the invention, a high-frequency square wave voltage slightly greater than the partial discharge initiation voltage is applied to the target epoxy material at different frequencies, different voltages, and different temperatures, and the withstand voltage data corresponding to various external operating conditions are recorded by a computer program.

[0070] Step 104: Perform high-frequency withstand voltage analysis on each withstand voltage data to obtain the insulation withstand voltage index corresponding to the initial epoxy material sample.

[0071] In this embodiment of the invention, each withstand voltage data is input into a preset withstand voltage exponent function to obtain the initial withstand voltage exponent corresponding to each withstand voltage data. Each withstand voltage data and its corresponding initial withstand voltage exponent are then input into a preset inverse power function to obtain the predicted insulation life data corresponding to each withstand voltage data. Each withstand voltage data and its corresponding predicted insulation life data are then input into a preset fitting regression function to obtain a goodness-of-fit value. The maximum value among all goodness-of-fit values ​​is selected as the target goodness-of-fit value, and the initial withstand voltage exponent associated with the target goodness-of-fit value is used as the initial insulation withstand voltage exponent corresponding to the initial epoxy material sample.

[0072] It should be noted that the pressure resistance exponent function is as follows:

[0073]

[0074] in, For insulation life, External operating condition parameters, d is the first tolerance coefficient, and b is the second tolerance coefficient (initial pressure index d = -b).

[0075] The inverse power function is specifically:

[0076]

[0077] in, For electric field strength, It is the time it takes for the insulating material to break down under an electric field strength E (i.e., insulation life). d is the threshold for dielectric to withstand electrical damage, and d and Dc are constants for samples of the same specifications.

[0078] The fitted regression function is as follows:

[0079]

[0080] in, The predicted value of the target variable for the sample is the predicted insulation lifetime obtained by calculating using an inverse power function. This represents the true value of the target variable in the sample, i.e., the measured insulation life. The average of the target variable for the sample. This represents the goodness-of-fit value.

[0081] In this embodiment of the invention, by performing insulation withstand voltage testing on the target epoxy material according to various preset external operating parameters and partial discharge initiation voltage, withstand voltage data corresponding to various external operating parameters are obtained. The insulation withstand voltage index of the epoxy resin under high-frequency square waves can then be obtained by fitting these withstand voltage data. This overcomes the technical problem that while the constant stress method can obtain the withstand voltage index of epoxy materials by acquiring insulation failure times under different constant electric fields, it does not fully consider the influence of high-frequency square waves on the epoxy material, leading to inaccurate calculation results for the withstand voltage index of epoxy materials under high-frequency square waves. Compared with traditional withstand voltage index calculation methods, this invention performs insulation withstand voltage testing on the target epoxy material according to various preset external operating parameters and partial discharge initiation voltage, obtaining multiple withstand voltage data. This directly reflects the influence of high-frequency square waves on epoxy materials, improving the accuracy of the calculated withstand voltage index of epoxy materials under high-frequency square waves.

[0082] Please see Figure 2 , Figure 2 This is a flowchart illustrating the steps of a method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave conditions, as provided in Embodiment 2 of the present invention.

[0083] This invention provides a method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave conditions, comprising:

[0084] Step 201: Obtain an initial epoxy material sample and perform a detection pretreatment on the initial epoxy material sample to obtain the target epoxy material sample.

[0085] Further, step 201 includes the following sub-steps:

[0086] S11. Add the preset curing agent and accelerator to the initial epoxy material sample to generate the first epoxy material sample;

[0087] In this embodiment of the invention, an initial epoxy material sample, a preset curing agent, and an accelerator are added to the container of a centrifugal mixer in a mass ratio of 100:80:0.6 and stirred to generate a first epoxy material sample.

[0088] It should be noted that the control process of the centrifugal mixer is as follows: the speed of the mixing and dispersion process is 2000 r / min for 15 min, and the speed of the degassing process is 2200 r / min for 15 min.

[0089] S12. Degas the first epoxy material sample to obtain the second epoxy material sample.

[0090] In this embodiment of the invention, the first epoxy material sample is poured into a mold with a 0.1 mm thick stainless steel clip, and then the mold is placed in a vacuum blower electric heating drying oven. Vacuuming is performed at room temperature, and degassing is carried out for 30 minutes to remove air bubbles from the sample, thereby obtaining the second epoxy material sample.

[0091] S13. The second epoxy material sample is cured to obtain the target epoxy material sample.

[0092] In this embodiment of the invention, the second epoxy material sample is placed in an oven, the oven air inlet knob is turned on, and curing is performed under normal pressure to obtain the target epoxy material sample.

[0093] It should be noted that the oven control process is as follows: cure at 80℃ for 2 hours, then raise the temperature to 140℃ for 10 minutes, and cure at 140℃ for 12 hours.

[0094] Step 202: Perform partial discharge detection on the target epoxy material sample to obtain the partial discharge initiation voltage;

[0095] Further, step 202 includes the following sub-steps:

[0096] S21. Partial discharge test was performed on the target epoxy material sample using the linear boost method to obtain partial discharge data;

[0097] In this embodiment of the invention, based on the linear boost method, a partial discharge test is performed on the target epoxy material sample through a preset partial discharge test platform to obtain partial discharge data.

[0098] It should be noted that the partial discharge test platform includes a bipolar square wave voltage source 8, a high-voltage probe 7, a cylindrical electrode 5, a UHF sensor 4, a high-pass filter 3, a PC terminal 1, a 1GHz bandwidth digital oscilloscope 2, and an insulation resistance 6. The UHF sensor 4 can measure the real-time partial discharge signal, and the frequency range of the signal measured by the UHF sensor 4 is 300MHz-1500MHz.

[0099] S22. Perform Fourier spectrum analysis on the partial discharge data to obtain multiple partial discharge spectrum values;

[0100] In this embodiment of the invention, the partial discharge data is subjected to Fourier spectrum analysis by a 1GHz bandwidth digital oscilloscope 3 on the partial discharge test platform to obtain the partial discharge spectrum values ​​corresponding to each moment during the partial discharge test.

[0101] S23. Determine whether each partial discharge spectrum value is greater than the preset partial discharge frequency threshold.

[0102] S24. When the partial discharge spectrum value is greater than the partial discharge frequency threshold, the partial discharge spectrum value is determined as the target spectrum value.

[0103] The partial discharge frequency threshold refers to the starting frequency of the partial discharge spectrum, with a value of 400MHz.

[0104] In this embodiment of the invention, it is determined whether each partial discharge spectrum value is greater than 400MHz. When the partial discharge spectrum value is greater than 400MHz, the partial discharge spectrum value is determined as the target spectrum value.

[0105] S25. Select the minimum value among the test voltages associated with each target spectrum value as the partial discharge initiation voltage.

[0106] In this embodiment of the invention, the minimum value among the test voltages associated with all target spectrum values ​​is selected as the partial discharge initiation voltage.

[0107] In another embodiment, the target epoxy material sample is linearly boosted using a preset partial discharge test platform. When a partial discharge signal is detected, the test voltage at the current moment is selected as the partial discharge initiation voltage.

[0108] Step 203: According to the preset external operating condition parameters, the insulation withstand voltage of the target epoxy material is tested using the partial discharge initiation voltage to obtain the withstand voltage data corresponding to various external operating condition parameters;

[0109] In this embodiment of the invention, based on a variety of preset external operating parameters, the high-frequency square wave voltage of the partial discharge test platform is adjusted to be slightly higher than the partial discharge initiation voltage. The insulation withstand voltage of the target epoxy material is then tested through the partial discharge test platform to obtain the withstand voltage data corresponding to various external operating parameters.

[0110] It should be noted that external operating parameters include frequency parameters, temperature parameters, and voltage parameters.

[0111] Step 204: Input each pressure resistance data into the preset pressure resistance index function to obtain the initial pressure resistance index corresponding to each pressure resistance data;

[0112] In this embodiment of the invention, the initial pressure resistance index corresponding to each pressure resistance data is calculated by a preset pressure resistance index function.

[0113] Step 205: Input each withstand voltage data and the initial withstand voltage index corresponding to each withstand voltage data into the preset inverse power function to obtain the predicted insulation life data corresponding to each withstand voltage data.

[0114] Predicted insulation life data refers to the insulation life calculated from different external operating condition parameters in the withstand voltage data.

[0115] In this embodiment of the invention, each withstand voltage data and its corresponding initial withstand voltage index are input into a preset inverse power function. This yields the predicted insulation life data corresponding to each withstand voltage data.

[0116] Step 206: Evaluate the goodness of fit of all withstand voltage data based on each predicted insulation life data, and obtain the goodness of fit value corresponding to each withstand voltage data.

[0117] Furthermore, step 206 includes the following sub-steps:

[0118] S31. Average the actual insulation life in each withstand voltage data to obtain the first average value corresponding to each withstand voltage data.

[0119] In this embodiment of the invention, the average value of the actual insulation life in each withstand voltage data is calculated to obtain the first average value corresponding to each withstand voltage data.

[0120] S32. Perform difference processing on the actual insulation life and the associated first mean value in each withstand voltage data to obtain the first difference value corresponding to each withstand voltage data.

[0121] In this embodiment of the invention, the difference between the actual insulation life and the associated first mean in each withstand voltage data is calculated to obtain the first difference corresponding to each withstand voltage data.

[0122] S33. Perform difference processing on the predicted insulation life and the associated first mean in each predicted insulation life data to obtain the second difference corresponding to each predicted insulation life data.

[0123] In this embodiment of the invention, the difference between the predicted insulation lifetime and the associated first mean in each predicted insulation lifetime data is calculated to obtain the second difference corresponding to each predicted insulation lifetime data.

[0124] S34. Perform a sum of squares on the first difference corresponding to each withstand voltage data to obtain the first sum of squares corresponding to each withstand voltage data.

[0125] In this embodiment of the invention, the sum of squares of the first differences corresponding to each withstand pressure data is calculated to obtain the first sum of squares value corresponding to each withstand pressure data.

[0126] S35. Perform a sum of squares on the second difference corresponding to each predicted insulation life data to obtain the second sum of squares corresponding to each predicted insulation life data.

[0127] In this embodiment of the invention, the sum of squares of the second differences corresponding to each predicted insulation lifetime data is calculated to obtain the second sum of squares value corresponding to each predicted insulation lifetime data.

[0128] S36. Ratio the first and second sums of squares corresponding to each pressure resistance data to obtain the goodness-of-fit value for each pressure resistance data.

[0129] In this embodiment of the invention, the ratio between the first sum of squares and the second sum of squares corresponding to each pressure resistance data is calculated to obtain the goodness-of-fit value corresponding to each pressure resistance data.

[0130] Step 207: Select the maximum value of each goodness-of-fit value as the target goodness-of-fit value, and use the initial withstand voltage index associated with the target goodness-of-fit value as the insulation withstand voltage index corresponding to the initial epoxy material sample.

[0131] In this embodiment of the invention, the maximum value of all goodness-of-fit values ​​is selected as the target goodness-of-fit value, and the initial withstand voltage index associated with the target goodness-of-fit value is used as the insulation withstand voltage index corresponding to the initial epoxy material sample.

[0132] It should be noted that the higher the goodness-of-fit value, the better the regression fit. Generally, a goodness-of-fit value above 0.8 is considered to be relatively high.

[0133] It is worth mentioning that insulation life tests were conducted using steps 201-206, measuring the insulation life under different voltage levels, frequencies, and temperatures, and performing life fitting and calculating the insulation withstand voltage index. (See also...) Figures 4-5 As shown, there are schematic diagrams of data fitting for the effect of voltage on epoxy resin and the effect of frequency on epoxy resin.

[0134] Typically, the voltage type in high-frequency transformers is a high-frequency bipolar square wave with a frequency of 10kHz and a voltage level of 2kV. Therefore, the experimental parameters are based on a bipolar square wave voltage with an amplitude of 2kV and a frequency of 10kHz. The insulation life is measured at different frequencies of 1kHz, 5kHz, 10kHz, 15kHz, and 20kHz, and at different voltages of 1.5kV, 2kV, 2.5kV, 3kV, and 4kV, and then life fitting is performed.

[0135] Based on the above method, we can obtain:

[0136] Fitting results of insulation life and insulation withstand voltage index at different frequencies:

[0137] The insulation withstand index n = 0.85714, R 2 =0.998;

[0138] Fitting results of insulation life and insulation withstand voltage index under different voltages:

[0139] The insulation withstand index n=2.47234, R 2 =0.995.

[0140] According to the fitting results, voltage magnitude and voltage frequency satisfy an inverse power function model with respect to insulation life, and the insulation tolerance index n f <n u Frequency variation has a greater impact on insulation life. The insulation life of epoxy resin materials is related to the frequency and magnitude of the applied voltage.

[0141] In this embodiment of the invention, by performing insulation withstand voltage testing on the target epoxy material according to various preset external operating parameters and partial discharge initiation voltage, withstand voltage data corresponding to various external operating parameters are obtained. The insulation withstand voltage index of the epoxy resin under high-frequency square waves can then be obtained by fitting these withstand voltage data. This overcomes the technical problem that while the constant stress method can obtain the withstand voltage index of epoxy materials by acquiring insulation failure times under different constant electric fields, it does not fully consider the influence of high-frequency square waves on the epoxy material, leading to inaccurate calculation results for the withstand voltage index of epoxy materials under high-frequency square waves. Compared with traditional withstand voltage index calculation methods, this invention performs insulation withstand voltage testing on the target epoxy material according to various preset external operating parameters and partial discharge initiation voltage, obtaining multiple withstand voltage data. This directly reflects the influence of high-frequency square waves on epoxy materials, improving the accuracy of the calculated withstand voltage index of epoxy materials under high-frequency square waves.

[0142] Please see Figure 6 , Figure 6 This is a structural block diagram of a system for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave, as provided in Embodiment 3 of the present invention.

[0143] This invention provides a system for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave conditions, comprising:

[0144] The pretreatment module 301 is used to obtain an initial epoxy material sample and perform detection pretreatment on the initial epoxy material sample to obtain a target epoxy material sample.

[0145] Partial discharge detection module 302 is used to perform partial discharge detection on the target epoxy material sample to obtain the partial discharge initiation voltage.

[0146] The withstand voltage testing module 303 is used to perform insulation withstand voltage testing on the target epoxy material according to a variety of preset external operating conditions parameters and the partial discharge initiation voltage, so as to obtain the withstand voltage data corresponding to various external operating conditions parameters.

[0147] The withstand voltage analysis module 304 is used to perform high-frequency withstand voltage analysis on various withstand voltage data to obtain the insulation withstand voltage index corresponding to the initial epoxy material sample.

[0148] Furthermore, the preprocessing module 301 includes:

[0149] The pretreatment submodule is used to add the preset curing agent and accelerator to the initial epoxy material sample to generate the first epoxy material sample;

[0150] The degassing submodule is used to degas the first epoxy material sample to obtain the second epoxy material sample.

[0151] The curing submodule is used to cure the second epoxy material sample to obtain the target epoxy material sample.

[0152] Furthermore, the partial discharge detection module 302 includes:

[0153] The partial discharge test submodule is used to perform partial discharge tests on the target epoxy material sample using the linear boost method to obtain partial discharge data.

[0154] The first analysis submodule is used to perform Fourier spectrum analysis on partial discharge data to obtain multiple partial discharge spectrum values;

[0155] The second analysis submodule is used to determine whether each partial discharge spectrum value is greater than the preset partial discharge frequency threshold.

[0156] When the partial discharge spectrum value is greater than the partial discharge frequency threshold, the partial discharge spectrum value is determined as the target spectrum value.

[0157] The minimum value among the test voltages associated with each target spectrum value is selected as the partial discharge initiation voltage.

[0158] Furthermore, the withstand voltage analysis module 304 includes:

[0159] The third analysis submodule is used to input each pressure resistance data into a preset pressure resistance index function to obtain the initial pressure resistance index corresponding to each pressure resistance data.

[0160] The fourth analysis submodule is used to input each withstand voltage data and the initial withstand voltage index corresponding to each withstand voltage data into a preset inverse power function to obtain the predicted insulation life data corresponding to each withstand voltage data.

[0161] The fifth analysis submodule is used to evaluate the goodness of fit of all withstand voltage data based on each predicted insulation life data, and obtain the goodness of fit value corresponding to each withstand voltage data.

[0162] The sixth analysis submodule is used to select the maximum value of each goodness-of-fit value as the target goodness-of-fit value, and to use the initial withstand voltage index associated with the target goodness-of-fit value as the insulation withstand voltage index corresponding to the initial epoxy material sample.

[0163] Furthermore, the fifth analysis submodule includes:

[0164] The averaging unit is used to average the actual insulation life in each withstand voltage data to obtain the first average value corresponding to each withstand voltage data.

[0165] The difference unit is used to perform difference processing on the actual insulation life in each withstand voltage data and the associated first mean value to obtain the first difference value corresponding to each withstand voltage data.

[0166] The first analysis unit is used to perform difference processing on the predicted insulation life and the associated first mean in each predicted insulation life data to obtain the second difference corresponding to each predicted insulation life data.

[0167] The second analysis unit is used to perform square sum processing on the first difference corresponding to each withstand pressure data to obtain the first square sum value corresponding to each withstand pressure data.

[0168] The third analysis unit is used to perform square sum processing on the second difference corresponding to each predicted insulation life data to obtain the second square sum value corresponding to each predicted insulation life data.

[0169] The fourth analysis unit is used to perform ratio processing on the first and second sums of squares corresponding to each pressure resistance data to obtain the goodness-of-fit value corresponding to each pressure resistance data.

[0170] Furthermore, external operating parameters include frequency parameters, temperature parameters, and voltage parameters.

[0171] Please see Figure 7 , Figure 7 This is a structural block diagram of an electronic device provided in Embodiment 4 of the present invention.

[0172] An electronic device according to an embodiment of the present invention includes: a memory 401 and a processor 402. The memory 402 stores a computer program. When the computer program is executed by the processor 402, the processor 402 performs the calculation method of epoxy resin insulation withstand voltage index under high frequency square wave as described in any of the above embodiments.

[0173] Memory 401 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Memory 401 has storage space 403 for program code 413 for performing any of the method steps described above. For example, storage space 403 for program code may include individual program codes 413 for implementing the various steps in the methods described above. This program code may be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, compact discs (CDs), memory cards, or floppy disks. The program code may be compressed, for example, in a suitable form. When run by a computing processing device, this code causes the computing processing device to perform the various steps in the methods described above.

[0174] Embodiment 5 of the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square waves as described in any of the above embodiments.

[0175] Embodiment 6 of the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer performs the method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave as described in any of the above embodiments.

[0176] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0177] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0178] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0179] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0180] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0181] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave, characterized in that, include: An initial epoxy material sample is obtained, and the initial epoxy material sample is subjected to detection pretreatment to obtain the target epoxy material sample. Partial discharge detection was performed on the target epoxy material sample to obtain the partial discharge initiation voltage. According to a variety of preset external operating condition parameters, the partial discharge initiation voltage is used to perform insulation withstand voltage testing on the target epoxy material to obtain withstand voltage data corresponding to various external operating condition parameters; High-frequency withstand voltage analysis was performed on each of the withstand voltage data to obtain the insulation withstand voltage index corresponding to the initial epoxy material sample. The step of performing high-frequency withstand voltage analysis on each of the withstand voltage data to obtain the insulation withstand voltage index corresponding to the initial epoxy material sample includes: Each of the pressure resistance data is input into a preset pressure resistance index function to obtain the initial pressure resistance index corresponding to each of the pressure resistance data. Each withstand voltage data and the initial withstand voltage index corresponding to each withstand voltage data are input into a preset inverse power function to obtain the predicted insulation life data corresponding to each withstand voltage data. Based on the predicted insulation life data, the goodness of fit of all the withstand voltage data is evaluated to obtain the goodness of fit value corresponding to each withstand voltage data. The maximum value of each of the goodness-of-fit values ​​is selected as the target goodness-of-fit value, and the initial withstand voltage index associated with the target goodness-of-fit value is used as the insulation withstand voltage index corresponding to the initial epoxy material sample. The step of evaluating the goodness of fit of all the withstand voltage data based on each of the predicted insulation life data to obtain the goodness of fit value corresponding to each of the withstand voltage data includes: The actual insulation life in each of the withstand voltage data is averaged to obtain the first average value corresponding to each withstand voltage data. The actual insulation life in each of the withstand voltage data is compared with the associated first mean value to obtain the first difference value corresponding to each of the withstand voltage data. The predicted insulation life in each of the predicted insulation life data is compared with the associated first mean to obtain the second difference value corresponding to each of the predicted insulation life data. The first difference corresponding to each of the aforementioned pressure resistance data is summed by squares to obtain the first sum of squares corresponding to each of the aforementioned pressure resistance data. The second difference corresponding to each of the predicted insulation life data is summed by squares to obtain the second sum of squares corresponding to each of the predicted insulation life data. The first sum of squares and the second sum of squares corresponding to each of the pressure resistance data are compared to obtain the goodness-of-fit value corresponding to each of the pressure resistance data.

2. The method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave as described in claim 1, characterized in that, The step of performing a pretreatment test on the initial epoxy material sample to obtain the target epoxy material sample includes: A pre-set curing agent and accelerator are added to the initial epoxy material sample to generate a first epoxy material sample; The first epoxy material sample was degassed to obtain the second epoxy material sample. The second epoxy material sample was cured to obtain the target epoxy material sample.

3. The method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave as described in claim 1, characterized in that, The step of performing partial discharge detection on the target epoxy material sample to obtain the partial discharge initiation voltage includes: Partial discharge tests were performed on the target epoxy material sample using a linear boost method to obtain partial discharge data. Fourier spectrum analysis was performed on the partial discharge data to obtain multiple partial discharge spectrum values; Each partial discharge spectrum value is determined to be greater than a preset partial discharge frequency threshold. When the partial discharge spectrum value is greater than the partial discharge frequency threshold, the partial discharge spectrum value is determined as the target spectrum value. The minimum value among the test voltages associated with each of the target spectrum values ​​is selected as the partial discharge initiation voltage.

4. The method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave as described in claim 1, characterized in that, The external operating parameters include frequency parameters, temperature parameters, and voltage parameters.

5. A system for calculating the withstand voltage index of epoxy resin insulation under high-frequency square wave, based on the calculation method for the withstand voltage index of epoxy resin insulation under high-frequency square wave as described in any one of claims 1-4, characterized in that, include: The pretreatment module is used to obtain an initial epoxy material sample and perform detection pretreatment on the initial epoxy material sample to obtain a target epoxy material sample. The partial discharge detection module is used to perform partial discharge detection on the target epoxy material sample to obtain the partial discharge initiation voltage. The withstand voltage testing module is used to perform insulation withstand voltage testing on the target epoxy material according to a variety of preset external operating condition parameters and the partial discharge initiation voltage, so as to obtain withstand voltage data corresponding to various external operating condition parameters. The withstand voltage analysis module is used to perform high-frequency withstand voltage analysis on each of the withstand voltage data to obtain the insulation withstand voltage index corresponding to the initial epoxy material sample.

6. An electronic device, characterized in that, The device includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of the method for calculating the withstand voltage index of epoxy resin insulation under high-frequency square waves as described in any one of claims 1-4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed, it implements the method for calculating the epoxy resin insulation withstand voltage index under high-frequency square wave as described in any one of claims 1-4.

8. A computer program product, characterized in that, The computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, wherein when the program instructions are executed by a computer, the computer performs the method for calculating the epoxy resin insulation withstand voltage index under high-frequency square wave as described in any one of claims 1-4.

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