Method and system for calculating insulation voltage resistance index of epoxy resin under high-frequency square wave

Abstract

The invention discloses a method and a system for calculating the insulation voltage-withstanding index of epoxy resin under high-frequency square waves, and relates to the technical field of insulation voltage-withstanding index calculation, an initial epoxy material sample is obtained, the initial epoxy material sample is subjected to detection pretreatment, a target epoxy material sample is obtained, the target epoxy material sample is subjected to partial discharge detection, and the insulation voltage-withstanding index of epoxy resin under high-frequency square waves is obtained. The method comprises the following steps: obtaining a partial discharge initial voltage, carrying out insulation and voltage resistance detection on a target epoxy material by adopting the partial discharge initial voltage according to a plurality of preset external working condition parameters to obtain voltage resistance data corresponding to the various external working condition parameters, and carrying out high-frequency voltage resistance analysis on the voltage resistance data to obtain an insulation and voltage resistance index corresponding to an initial epoxy material sample. The technical problem that the voltage-withstanding index of the epoxy material can be obtained in a fitting mode by obtaining the insulation failure time under different constant electric fields through a constant stress method, but the influence of high-frequency square waves on the epoxy material is not fully considered, so that the voltage-withstanding index calculation result of the epoxy material under the high-frequency square waves is not accurate is solved.

Description

Technical Field

[0001] The invention relates to the technical field of insulation withstand voltage index calculation, and in particular to a method and system for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves. Background Art

[0002] Epoxy resin is one of the most important insulating materials. It is a material with a 3D network structure and permanent covalent cross-linking bonds. This material has high mechanical strength, dimensional stability, and resistance to high temperature and chemical corrosion. It has a wide range of applications in the field of power electronics. However, with the continuous improvement of the voltage level and power of power electronic equipment, high-frequency power electronic devices need to withstand transient bipolar square waves before and after the DC-DC converter. In addition, due to the presence of stray parameters such as leakage inductance and distributed capacitance of high-frequency transformers, epoxy materials of high-frequency power electronic equipment are subjected to high-repetition-frequency electrical stress shocks for a long time, and the probability of breakdown and surface flashover increases significantly. Therefore, studying the withstand voltage index of epoxy materials under high-frequency square waves is of great significance to the optimization design of epoxy material structures of high-frequency power electronic devices.

[0003] At present, the constant stress method is used to obtain the insulation failure time under different constant electric fields, and the withstand voltage index of epoxy materials can be fitted. 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] The present invention provides a method and system for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves, which solves the technical problem that the constant stress method is used to obtain the insulation failure time under different constant electric fields to fit the withstand voltage index of the epoxy material, but the influence of the high-frequency square wave on the epoxy material is not fully considered, resulting in inaccurate calculation results of the withstand voltage index of the epoxy material under high-frequency square waves.

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

[0006] Obtaining an initial epoxy material sample, and performing detection pretreatment on the initial epoxy material sample to obtain a target epoxy material sample;

[0007] Performing partial discharge detection on the target epoxy material sample to obtain a partial discharge inception voltage;

[0008] According to a plurality of preset external working condition parameters, the target epoxy material is subjected to insulation withstand voltage testing using the partial discharge starting voltage to obtain withstand voltage data corresponding to the various external working condition parameters;

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

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

[0011] Adding a preset curing agent and accelerator to the initial epoxy material sample to generate a first epoxy material sample;

[0012] Degassing the first epoxy material sample to obtain a second epoxy material sample;

[0013] The second epoxy material sample is cured to obtain a target epoxy material sample.

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

[0015] Conducting a partial discharge test on the target epoxy material sample by a linear voltage step-up method to obtain partial discharge data;

[0016] Performing Fourier spectrum analysis on the partial discharge data to obtain a plurality of partial discharge spectrum values;

[0017] Determining whether each of the partial discharge spectrum values ​​is greater than a preset partial discharge frequency threshold;

[0018] When the partial discharge spectrum value is greater than the partial discharge frequency threshold, determining the partial discharge spectrum value as a target spectrum value;

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

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

[0021] Inputting each of the withstand voltage data into a preset withstand voltage index function to obtain an initial withstand voltage index corresponding to each of the withstand voltage data;

[0022] Inputting each of the withstand voltage data and the initial withstand voltage index corresponding to each of the withstand voltage data into a preset inverse power function to obtain predicted insulation life data corresponding to each of the withstand voltage data;

[0023] Performing a goodness of fit evaluation on all the withstand voltage data according to each of the predicted insulation life data to obtain a goodness of fit value corresponding to each of the withstand voltage data;

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

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

[0026] respectively performing mean processing on the actual insulation life in each of the withstand voltage data to obtain a first mean value corresponding to each of the withstand voltage data;

[0027] Performing difference processing on the actual insulation life in each of the withstand voltage data and the associated first mean value respectively, to obtain the first difference value corresponding to each of the withstand voltage data;

[0028] Performing difference processing on the predicted insulation life in each of the predicted insulation life data and the associated first mean value respectively, to obtain a second difference value corresponding to each of the predicted insulation life data;

[0029] Performing square sum processing on the first difference values ​​corresponding to the withstand voltage data respectively to obtain the first square sum value corresponding to the withstand voltage data;

[0030] Performing square sum processing on the second difference values ​​corresponding to the predicted insulation life data respectively to obtain the second square sum value corresponding to the predicted insulation life data;

[0031] The first square sum value and the second square sum value corresponding to each of the withstand voltage data are respectively subjected to ratio processing to obtain a goodness of fit value corresponding to each of the withstand voltage data.

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

[0033] A second aspect of the present invention provides a system for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves, comprising:

[0034] A preprocessing module is used to obtain an initial epoxy material sample and perform detection preprocessing on the initial epoxy material sample to obtain a target epoxy material sample;

[0035] A partial discharge detection module, used for performing partial discharge detection on the target epoxy material sample to obtain a partial discharge starting voltage;

[0036] A withstand voltage detection module, used to perform insulation withstand voltage detection on the target epoxy material according to a plurality of preset external working condition parameters using the partial discharge starting voltage, and obtain withstand voltage data corresponding to various external working 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, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves as described in any of the above items.

[0039] A 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, the method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves as described in any one of the above items is implemented.

[0040] A fifth aspect of the present invention provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer executes the method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves as described in any one of the above items.

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

[0042] By using a partial discharge starting voltage to perform insulation withstand voltage detection on the target epoxy material according to a plurality of preset external operating parameters, the withstand voltage data corresponding to the various external operating parameters can be obtained, so that the insulation withstand voltage index of the epoxy resin under a high-frequency square wave can be obtained by fitting through each withstand voltage data. This overcomes the technical problem that the withstand voltage index of the epoxy material can be obtained by fitting by using the constant stress method by obtaining the insulation failure time under different constant electric fields, but the influence of the high-frequency square wave on the epoxy material is not fully considered, resulting in inaccurate calculation results of the withstand voltage index of the epoxy material under a high-frequency square wave. Compared with the traditional withstand voltage index calculation method, the present invention performs insulation withstand voltage detection on the target epoxy material according to a plurality of preset external operating parameters and the partial discharge starting voltage, and obtains a plurality of withstand voltage data, which can intuitively reflect the influence of the high-frequency square wave on the epoxy material, and improves the accuracy of the withstand voltage index calculation results of the epoxy material under a high-frequency square wave. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0044] Figure 1 A flowchart of a method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves provided in Example 1 of the present invention;

[0045] Figure 2 A flowchart of a method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves provided in the second embodiment of the present invention;

[0046] Figure 3 A schematic diagram of the structure of a partial discharge and insulation life test platform provided in the second embodiment of the present invention;

[0047] Figure 4 A data fitting diagram of the effect of voltage on epoxy resin provided in Example 2 of the present invention;

[0048] Figure 5 A data fitting diagram of the effect of frequency on epoxy resin provided in Example 2 of the present invention;

[0049] Figure 6 A structural block diagram of a system for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves provided in Embodiment 3 of the present invention;

[0050] Figure 7 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. Column-plate electrode; 6. Insulation resistance; 7. High-voltage probe; 8. Bipolar square wave voltage source. DETAILED DESCRIPTION

[0053] The embodiment of the present invention provides a method and system for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves, which is used to solve the technical problem that the constant stress method is used to obtain the insulation failure time under different constant electric fields, and the withstand voltage index of the epoxy material can be fitted, but the influence of the high-frequency square wave on the epoxy material is not fully considered, resulting in inaccurate calculation results of the withstand voltage index of the epoxy material under high-frequency square waves.

[0054] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below 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.

[0055] See also Figure 1 , Figure 1 A flowchart of the steps of a method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves provided in Example 1 of the present invention.

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

[0057] Step 101, obtaining an initial epoxy material sample, and performing detection pretreatment on the initial epoxy material sample to obtain a 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 0.1mm epoxy resin sample.

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

[0061] Step 102, performing partial discharge detection on the target epoxy material sample to obtain a partial discharge inception voltage;

[0062] The partial discharge inception voltage refers to the partial discharge inception voltage of the target epoxy material sample.

[0063] In the embodiment of the present invention, a linear voltage boost method is adopted to perform partial discharge detection on a target epoxy material through a preset partial discharge test platform to obtain a partial discharge inception voltage corresponding to the target epoxy material.

[0064] In another embodiment, a PDIV measurement method is used to perform partial discharge detection on a target epoxy material to obtain a partial discharge inception voltage corresponding to the target epoxy material.

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

[0066] Step 103, according to a plurality of preset external working condition parameters, the insulation withstand voltage test is performed on the target epoxy material using the partial discharge starting voltage to obtain withstand voltage data corresponding to the various external working condition parameters;

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

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

[0069] In an embodiment of the present invention, a high-frequency square wave voltage slightly greater than the partial discharge starting 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 parameters are recorded through a computer program.

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

[0071] In an embodiment of the present invention, each withstand voltage data is input into a preset withstand voltage index function to obtain an initial withstand voltage index corresponding to each withstand voltage 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 predicted insulation life data corresponding to each withstand voltage data. Each withstand voltage data and the predicted insulation life data corresponding to each withstand voltage data are input into a preset fitting regression function to obtain a goodness of fit value. The maximum value is selected from all goodness of fit values ​​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.

[0072] It should be noted that the withstand voltage index function is specifically:

[0073]

[0074] in, is the insulation life, is the external working condition parameter, is the first tolerance coefficient, b is the second tolerance coefficient (initial withstand voltage index d=-b).

[0075] The inverse power function is specifically:

[0076]

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

[0078] The specific fitting regression function is:

[0079]

[0080] in, is the predicted value of the sample target variable, that is, the predicted insulation life calculated by the inverse power function, is the true value of the sample target variable, that is, the insulation life obtained by measurement, is the sample target variable mean, is the goodness of fit value.

[0081] In an embodiment of the present invention, the insulation withstand voltage test of the target epoxy material is performed according to a plurality of preset external working condition parameters and a partial discharge starting voltage, and the withstand voltage data corresponding to the various external working condition parameters are obtained, so that the insulation withstand voltage index of the epoxy resin under a high-frequency square wave can be obtained by fitting through each withstand voltage data. The constant stress method is used to obtain the withstand voltage index of the epoxy material by fitting by obtaining the insulation failure time under different constant electric fields, but the influence of the high-frequency square wave on the epoxy material is not fully considered, resulting in the technical problem that the calculation result of the withstand voltage index of the epoxy material under a high-frequency square wave is not accurate. Compared with the traditional withstand voltage index calculation method, the present invention performs the insulation withstand voltage test of the target epoxy material according to a plurality of preset external working condition parameters and a partial discharge starting voltage, and obtains a plurality of withstand voltage data, which can intuitively reflect the influence of the high-frequency square wave on the epoxy material, and improves the accuracy of the withstand voltage index calculation result of the epoxy material under a high-frequency square wave.

[0082] See also Figure 2 , Figure 2 A flowchart of the steps of a method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves provided in Example 2 of the present invention.

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

[0084] Step 201, obtaining an initial epoxy material sample, and performing detection pretreatment on the initial epoxy material sample to obtain a target epoxy material sample;

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

[0086] S11, adding a preset curing agent and accelerator to the initial epoxy material sample to generate a first epoxy material sample;

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

[0088] It should be noted that the control process of the centrifugal mixer is specifically as follows: the speed of the stirring and dispersing process is 2000 r / min, which lasts for 15 minutes, and the speed of the degassing process is 2200 r / min, which lasts for 15 minutes.

[0089] S12, degassing the first epoxy material sample to obtain a second epoxy material sample;

[0090] In an embodiment of the present invention, a first epoxy material sample is poured into a mold embedded with a 0.1 mm thick stainless steel clip, and then the mold is placed in a vacuum blast electric heating drying oven, evacuated at room temperature, and degassed for 30 minutes to remove bubbles in the sample, thereby obtaining a second epoxy material sample.

[0091] S13, curing the second epoxy material sample to obtain a target epoxy material sample.

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

[0093] It should be noted that the control process of the oven is specifically as follows: curing at 80°C for 2 h, then heating to 140°C for 10 min, and curing at 140°C for 12 h.

[0094] Step 202, performing partial discharge detection on the target epoxy material sample to obtain a partial discharge inception voltage;

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

[0096] S21, using a linear boost method to perform a partial discharge test on a target epoxy material sample to obtain partial discharge data;

[0097] In the embodiment of the present invention, based on the linear voltage boost method, a partial discharge test is performed on a 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 column plate electrode 5, a UHF sensor 4, a high pass filter 3, a PC terminal 1, a 1 GHz bandwidth digital oscilloscope 2 and an insulation resistor 6. The UHF sensor 4 can obtain a real-time partial discharge signal, and the frequency range of the signal measured by the UHF sensor 4 is 300 MHz-1500 MHz.

[0099] S22, performing Fourier spectrum analysis on the partial discharge data to obtain a plurality of partial discharge spectrum values;

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

[0101] S23, respectively determining whether each partial discharge spectrum value is greater than a preset partial discharge frequency threshold;

[0102] S24, when the local discharge spectrum value is greater than the local discharge frequency threshold, the local 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, and its value is 400MHz.

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

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

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

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

[0108] Step 203, according to the preset multiple external working condition parameters, the insulation withstand voltage test is performed on the target epoxy material using the partial discharge starting voltage to obtain the withstand voltage data corresponding to the various external working condition parameters;

[0109] In an embodiment of the present invention, based on a plurality of preset external operating parameters, after adjusting the high-frequency square wave voltage of the partial discharge test platform to be slightly higher than the partial discharge starting voltage, the insulation withstand voltage test is performed on the target epoxy material through the partial discharge test platform to obtain the withstand voltage data corresponding to the various external operating parameters.

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

[0111] Step 204: input each withstand voltage data into a preset withstand voltage index function to obtain an initial withstand voltage index corresponding to each withstand voltage data;

[0112] In the embodiment of the present invention, the initial withstand voltage index corresponding to each withstand voltage data is calculated respectively by using a preset withstand voltage index function.

[0113] Step 205, inputting each withstand voltage data and the initial withstand voltage index corresponding to each withstand voltage data into a preset inverse power function to obtain predicted insulation life data corresponding to each withstand voltage data;

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

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

[0116] Step 206: perform goodness of fit evaluation on all withstand voltage data according to each predicted insulation life data, and obtain a goodness of fit value corresponding to each withstand voltage data;

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

[0118] S31, respectively performing mean processing on the actual insulation life in each withstand voltage data to obtain a first mean value corresponding to each withstand voltage data;

[0119] In the embodiment of the present invention, the average values ​​of the actual insulation life in each withstand voltage data are calculated respectively to obtain the first average values ​​corresponding to each withstand voltage data.

[0120] S32, performing difference processing on the actual insulation life in each withstand voltage data and the associated first mean value respectively, to obtain a first difference value corresponding to each withstand voltage data;

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

[0122] S33, performing difference processing on the predicted insulation life in each predicted insulation life data and the associated first mean value, respectively, to obtain a second difference value corresponding to each predicted insulation life data;

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

[0124] S34, performing square sum processing on the first difference values ​​corresponding to each withstand voltage data to obtain a first square sum value corresponding to each withstand voltage data;

[0125] In the embodiment of the present invention, the sum of squares of the first difference values ​​corresponding to each withstand voltage data is calculated respectively to obtain the first sum of squares value corresponding to each withstand voltage data.

[0126] S35, performing square sum processing on the second difference values ​​corresponding to each predicted insulation life data respectively to obtain the second square sum value corresponding to each predicted insulation life data;

[0127] In the embodiment of the present invention, the sum of squares of the second difference values ​​corresponding to each predicted insulation life data is calculated respectively to obtain the second sum of squares value corresponding to each predicted insulation life data.

[0128] S36 , performing ratio processing on the first square sum value and the second square sum value corresponding to each withstand voltage data, respectively, to obtain a goodness of fit value corresponding to each withstand voltage data.

[0129] In the embodiment of the present invention, the ratio between the first square sum value and the second square sum value corresponding to each withstand voltage data is calculated respectively to obtain the goodness of fit value corresponding to each withstand voltage data.

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

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

[0132] It should be noted that the larger the goodness of fit value, the better the regression fitting effect. It is generally believed that the model goodness of fit exceeding 0.8 is relatively high.

[0133] It is worth mentioning that the insulation life test is performed using steps 201 to 206 to test the insulation life under different voltages, different voltage frequencies, and different temperatures, and to perform life fitting and insulation withstand voltage index calculation. Figure 4-Figure 5 As shown, there is a data fitting diagram of the effect of voltage on epoxy resin and a data fitting diagram of the effect of frequency on epoxy resin.

[0134] Usually the voltage type in the high-frequency transformer 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 at different frequencies of 1kHz, 5kHz, 10kHz, 15kHz, and 20kHz, and the insulation life at different voltages of 1.5kV, 2kV, 2.5kV, 3kV, and 4kV are measured, and then the life fitting is performed.

[0135] According to the above method, we can get:

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

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

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

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

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

[0141] In an embodiment of the present invention, the insulation withstand voltage test of the target epoxy material is performed according to a plurality of preset external working condition parameters and a partial discharge starting voltage, and the withstand voltage data corresponding to the various external working condition parameters are obtained, so that the insulation withstand voltage index of the epoxy resin under a high-frequency square wave can be obtained by fitting through each withstand voltage data. The constant stress method is used to obtain the withstand voltage index of the epoxy material by fitting by obtaining the insulation failure time under different constant electric fields, but the influence of the high-frequency square wave on the epoxy material is not fully considered, resulting in the technical problem that the calculation result of the withstand voltage index of the epoxy material under a high-frequency square wave is not accurate. Compared with the traditional withstand voltage index calculation method, the present invention performs the insulation withstand voltage test of the target epoxy material according to a plurality of preset external working condition parameters and a partial discharge starting voltage, and obtains a plurality of withstand voltage data, which can intuitively reflect the influence of the high-frequency square wave on the epoxy material, and improves the accuracy of the withstand voltage index calculation result of the epoxy material under a high-frequency square wave.

[0142] See also Figure 6 , Figure 6 This is a structural block diagram of a system for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves provided in Example 3 of the present invention.

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

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

[0145] The partial discharge detection module 302 is used to perform partial discharge detection on the target epoxy material sample to obtain the partial discharge starting voltage;

[0146] The withstand voltage detection module 303 is used to perform insulation withstand voltage detection on the target epoxy material according to a plurality of preset external working condition parameters using the partial discharge starting voltage to obtain withstand voltage data corresponding to various external working condition parameters;

[0147] The withstand voltage analysis module 304 is used to 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.

[0148] Furthermore, the preprocessing module 301 includes:

[0149] A pretreatment submodule, used for adding a preset curing agent and an accelerator into the initial epoxy material sample to generate a first epoxy material sample;

[0150] A degassing submodule, used for degassing the first epoxy material sample to obtain a second epoxy material sample;

[0151] The curing submodule is used to perform a curing process on the second epoxy material sample to obtain a target epoxy material sample.

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

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

[0154] A first analysis submodule is used to perform Fourier spectrum analysis on the partial discharge data to obtain a plurality of partial discharge spectrum values;

[0155] The second analysis submodule is used to determine whether each partial discharge spectrum value is greater than a 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 of the test voltage associated with each target spectrum value is selected as the partial discharge starting voltage.

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

[0159] The third analysis submodule is used to input each withstand voltage data into a preset withstand voltage index function to obtain an initial withstand voltage index corresponding to each withstand voltage data;

[0160] A 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 predicted insulation life data corresponding to each withstand voltage data;

[0161] A fifth analysis submodule is used to perform a goodness of fit evaluation on all withstand voltage data according to each predicted insulation life data, and obtain a 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 value, and use the initial withstand voltage index associated with the target goodness value as the insulation withstand voltage index corresponding to the initial epoxy material sample.

[0163] Furthermore, the fifth analysis submodule includes:

[0164] A mean value unit is used to perform mean processing on the actual insulation life in each withstand voltage data to obtain a first mean value corresponding to each withstand voltage data;

[0165] A difference unit, used for performing difference processing on the actual insulation life in each withstand voltage data and the associated first mean value, respectively, to obtain a first difference value corresponding to each withstand voltage data;

[0166] A first analysis unit is used to perform difference processing on the predicted insulation life in each predicted insulation life data and the associated first mean value, so as to obtain a second difference value corresponding to each predicted insulation life data;

[0167] A second analysis unit is used to perform square sum processing on the first difference values ​​corresponding to each withstand voltage data to obtain a first square sum value corresponding to each withstand voltage data;

[0168] A third analysis unit is used to perform square sum processing on the second difference values ​​corresponding to each predicted insulation life data to obtain a 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 square sum value and the second square sum value corresponding to each withstand voltage data to obtain a goodness of fit value corresponding to each withstand voltage data.

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

[0171] See also 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, wherein the memory 402 stores a computer program; when the computer program is executed by the processor 402, the processor 402 executes a method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves as in any of the above embodiments.

[0173] The memory 401 may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk or a ROM. The memory 401 has a storage space 403 for a program code 413 for executing any method step in the above method. For example, the storage space 403 for the program code may include individual program codes 413 for implementing the various steps in the above method, respectively. These program codes may be read from or written to one or more computer program products. These computer program products include program code carriers such as a hard disk, a compact disk (CD), a memory card or a floppy disk. The program code may be compressed, for example, in an appropriate form. When these codes are run by a computing and processing device, the computing and processing device is caused to execute the various steps in the above-described method.

[0174] Embodiment 5 of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves as in any of the above embodiments is implemented.

[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, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes a method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves as in any of the above embodiments.

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

[0177] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

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

[0179] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0180] If the integrated unit is implemented in the form of 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. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0181] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves, characterized in that: include: Obtaining an initial epoxy material sample, and performing detection pretreatment on the initial epoxy material sample to obtain a target epoxy material sample; Performing partial discharge detection on the target epoxy material sample to obtain a partial discharge inception voltage; According to a plurality of preset external working condition parameters, the target epoxy material is subjected to insulation withstand voltage testing using the partial discharge starting voltage to obtain withstand voltage data corresponding to the various external working condition parameters; A high-frequency withstand voltage analysis is performed on each of the withstand voltage data to obtain an insulation withstand voltage index corresponding to the initial epoxy material sample.

2. The method for calculating the insulation withstand voltage index of epoxy resin under high frequency square wave according to claim 1, characterized in that: The step of performing detection pretreatment on the initial epoxy material sample to obtain the target epoxy material sample includes: Adding a preset curing agent and accelerator to the initial epoxy material sample to generate a first epoxy material sample; Degassing the first epoxy material sample to obtain a second epoxy material sample; The second epoxy material sample is cured to obtain a target epoxy material sample.

3. The method for calculating the insulation withstand voltage index of epoxy resin under high frequency square wave according to claim 1, characterized in that: The step of performing partial discharge detection on the target epoxy material sample to obtain the partial discharge starting voltage comprises: Conducting a partial discharge test on the target epoxy material sample by a linear voltage step-up method to obtain partial discharge data; Performing Fourier spectrum analysis on the partial discharge data to obtain a plurality of partial discharge spectrum values; Determining whether each of the partial discharge spectrum values ​​is greater than a preset partial discharge frequency threshold; When the partial discharge spectrum value is greater than the partial discharge frequency threshold, determining the partial discharge spectrum value as a target spectrum value; The minimum value among the test voltages associated with the target spectrum values ​​is selected as the partial discharge starting voltage.

4. The method for calculating the insulation withstand voltage index of epoxy resin under high frequency square wave according to claim 1, characterized in that: 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: Inputting each of the withstand voltage data into a preset withstand voltage index function to obtain an initial withstand voltage index corresponding to each of the withstand voltage data; Inputting each of the withstand voltage data and the initial withstand voltage index corresponding to each of the withstand voltage data into a preset inverse power function to obtain predicted insulation life data corresponding to each of the withstand voltage data; Performing a goodness of fit evaluation on all the withstand voltage data according to each of the predicted insulation life data to obtain a goodness of fit value corresponding to each of the withstand voltage data; The maximum value of each of the goodness of fit values ​​is selected as the target goodness value, and the initial withstand voltage index associated with the target goodness value is used as the insulation withstand voltage index corresponding to the initial epoxy material sample.

5. The method for calculating the insulation withstand voltage index of epoxy resin under high frequency square wave according to claim 4, characterized in that: The step of performing goodness of fit evaluation on all the withstand voltage data according to each of the predicted insulation life data to obtain a goodness of fit value corresponding to each of the withstand voltage data comprises: respectively performing mean processing on the actual insulation life in each of the withstand voltage data to obtain a first mean value corresponding to each of the withstand voltage data; Performing difference processing on the actual insulation life in each of the withstand voltage data and the associated first mean value respectively, to obtain the first difference value corresponding to each of the withstand voltage data; Performing difference processing on the predicted insulation life in each of the predicted insulation life data and the associated first mean value respectively, to obtain a second difference value corresponding to each of the predicted insulation life data; Performing square sum processing on the first difference values ​​corresponding to the withstand voltage data respectively to obtain the first square sum value corresponding to the withstand voltage data; Performing square sum processing on the second difference values ​​corresponding to the predicted insulation life data respectively to obtain the second square sum value corresponding to the predicted insulation life data; The first square sum value and the second square sum value corresponding to each of the withstand voltage data are respectively subjected to ratio processing to obtain a goodness of fit value corresponding to each of the withstand voltage data.

6. The method for calculating the insulation withstand voltage index of epoxy resin under high frequency square wave according to claim 1, characterized in that: The external operating condition parameters include frequency parameters, temperature parameters and voltage parameters.

7. A calculation system for epoxy resin insulation withstand voltage index under high frequency square wave, characterized in that: include: A preprocessing module is used to obtain an initial epoxy material sample and perform detection preprocessing on the initial epoxy material sample to obtain a target epoxy material sample; A partial discharge detection module, used for performing partial discharge detection on the target epoxy material sample to obtain a partial discharge starting voltage; A withstand voltage detection module, used to perform insulation withstand voltage detection on the target epoxy material according to a plurality of preset external working condition parameters using the partial discharge starting voltage, and obtain withstand voltage data corresponding to various external working 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.

8. An electronic device, characterized in that: It comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves as described in any one of claims 1 to 6 is implemented.

10. A computer program product, characterized in that The computer program product includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer executes the method for calculating the insulation withstand voltage index of epoxy resin under high-frequency square waves as described in any one of claims 1-6.

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