A method for obtaining a satellite high-voltage electronic component life model

Abstract

The application provides a satellite high-voltage electronic component life model calculation method, which can obtain the insulation performance life of a satellite high-voltage electronic component. The specific process of the method is as follows: setting an experimental condition: performing a high-accelerated life test under different electric stresses under constant temperature and vacuum conditions, and determining a test time corresponding to each applied working voltage; preparing a test sample: the sample is made according to the simulated actual insulation structure, and high-temperature drying is performed before the test; a test scheme: including a cold-heat alternating cycle test, an electric accelerated aging test and a non-destructive performance parameter detection; model fitting: based on the performance parameters obtained by the non-destructive performance parameter detection, a relationship curve between the withstand voltage multiple and the life is fitted, a fitting coefficient is obtained, and a satellite high-voltage electronic component life model is obtained based on the fitting coefficient.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of life prediction, and particularly relates to a satellite high-voltage electronic component life model acquisition method. BACKGROUND

[0002] At present, the aging life models of insulating materials mainly include phenomenological models and physical models. The phenomenological model is based on the observation of the life test results, and the life model is obtained by curve fitting according to the test results. The physical model studies the aging mechanism of the material, analyzes the chemical and physical characteristics of the test material, links the model parameters with the thermodynamic quantities and the microstructure characteristics of the material, analyzes the destruction mechanism of the material according to the physical and chemical properties of the material and local discharge, space charge, thermal electron and the like, and then the aging life model of the insulating material is constructed through test verification.

[0003] The phenomenological model can be used to describe the aging phenomena of the insulating material under the action of single stress or multiple stresses, which can be divided into threshold and non-threshold models. The insulating material aging models corresponding to the two kinds of aging phenomena are respectively called curve models and straight line models. On the double logarithmic or semilogarithmic coordinate graph, it presents a straight line, and this model is called a straight line model or a non-threshold model, which can be divided into a single factor model and a multiple factor aging model.

[0004] At present, the life cycle of the insulating material of the electronic product is usually evaluated by constructing a life model, and the inverse power model is a commonly used life model of the insulating material, which is an important basis for parameter setting in the related test of the electronic product. The inverse power model is as follows:

[0005] t=CE -n

[0006] In the formula, t is the failure time or failure frequency (under a given probability) of the sample, C is a constant representing the cumulative electrical damage required for material insulation failure, and n is a voltage resistance index, also known as an electrical life index. The two parameters C and n of the inverse power model of the insulating material are important parameters reflecting the life characteristics of the insulating material, and are affected by factors such as environment and material properties.

[0007] In the existing research, the step stress test is usually used for the insulating life research of the electronic product, and according to the statistics, most of the electronic products select the step stress (life) test parameters according to the engineering experience, the parameter setting is too subjective, and the test results have large differences. SUMMARY

[0008] Therefore, the application provides a satellite high-voltage electronic component life model acquisition method, which can obtain the insulating performance life of the satellite high-voltage electronic component.

[0009] The technical solutions of the application are as follows:

[0010] A satellite high-voltage electronic component life model acquisition method, the specific process is:

[0011] Set the experimental conditions: perform high-accelerated life tests under different electrical stresses under vacuum and constant temperature conditions, and determine the test time corresponding to each applied working voltage;

[0012] Test sample preparation: the sample is made according to the simulation of the actual insulation structure, and high-temperature drying is performed before the test;

[0013] Test scheme: including cold and hot alternating cycle test, electrical accelerated aging test and non-destructive performance parameter detection;

[0014] The cold and hot alternating cycle test: multiple vacuum cold and hot alternating cycle tests are performed, each cycle period T hours, each lasts T / 4 hours at low temperature and high temperature, and the two temperature conversion times are T / 4 hours;

[0015] The electrical accelerated aging test: in the set vacuum environment and temperature, sequentially perform electrical accelerated aging tests of different working voltages, and the electrical accelerated aging time under each working voltage is not less than the corresponding set time;

[0016] The non-destructive performance parameter detection is: measuring the dielectric properties of the test product before and after the electrical aging acceleration test and during the aging process, and when the diagnostic test determines that the test piece fails, the aging test is stopped;

[0017] Model fitting: based on the performance parameters obtained by the non-destructive performance parameter detection, the relationship curve between the withstand voltage multiple and the life is fitted, the fitting coefficient is obtained, and the satellite high-voltage electronic component life model is obtained based on the fitting coefficient.

[0018] Further, the application fits the relationship curve between the withstand voltage multiple and the life, and obtains the fitting coefficient as follows:

[0019]

[0020] Wherein, L is the expected life of the high-voltage electronic component; is the voltage acceleration multiple; n and K are the coefficients to be fitted.

[0021] Further, the application dries the selected test at a temperature of 80 DEG C for not less than 6 hours before performing the test.

[0022] Further, in the setting experiment condition, three voltage levels are selected, i.e. 3.0 times, 2.5 times and 2.1 times of the working voltage are respectively applied to the sample, and the test time of 3.0 times, 2.5 times and 2.1 times of the working voltage is not less than 100h, 600h and 2400h respectively; for the 3.0 times / 100h accelerated aging test, only the measurement of the aging characteristic parameter before aging and after 100h of aging is needed; for the 2.5 times / 600h accelerated aging test, the measurement of the aging characteristic parameter is designed to be performed once every 300h; for the 2.1 times / 2400h accelerated aging test, the measurement of the aging characteristic parameter is designed to be performed once every 1200h; during the parameter test process, when it is determined according to the measurement result that the test piece has failed, the test of the test piece is ended.

[0023] Further, the destructive performance parameter detection in the test scheme of the application is that, for the test piece that has completed the setting time of the accelerated aging test and has not failed, the measurement of the residual breakdown voltage is performed, and the residual breakdown voltage is compared and analyzed with the breakdown voltage of each unaged comparison sample.

[0024] Further, the constant temperature and vacuum condition in the application is that: the constant temperature of the test environment is 70 DEG C; the high-accelerated life test and the diagnostic test are performed in a vacuum environment, and the air pressure of the test box is not more than 5*10 -3 Pa.

[0025] Beneficial effects

[0026] Since the two parameters in the inverse power model need to be proposed in combination with engineering experience, the parameter setting is too subjective, and the sample size of the satellite high-voltage electronic component is small, and there is a lack of relevant test data, which leads to differences in the insulation life evaluation results of the satellite high-voltage electronic component. The application analyzes the insulation protection process of the satellite high-voltage electronic component in combination with the actual application situation of the satellite high-voltage electronic component in orbit, performs the accelerated life test by applying the electric stress, analyzes the insulation protection process of the satellite high-voltage electronic component according to the test result, and obtains the relationship between the withstand voltage multiple (U / Un) of the insulation system of the satellite high-voltage electronic component and the aging time t (h) through the ratio of the applied voltage to the actual working voltage, which can not only judge the insulation performance life of the satellite high-voltage electronic component under the applied voltage, but also provide method support for the subsequent evaluation of the insulation life of the satellite high-voltage electronic component. BRIEF DESCRIPTION OF DRAWINGS

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments 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.

[0028] Figure 1 A flowchart for aging testing and diagnostics;

[0029] Figure 2 The curve shows the relationship between the withstand voltage multiple (U / Un) and the lifetime t. Detailed Implementation

[0030] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0031] It should be noted that, in the absence of conflict, the following embodiments and features can be combined with each other; and, based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0032] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0033] This application employs an analytical method of first conducting experiments and then curve fitting. Taking high-voltage rectifier tubes, high-voltage relays, and high-frequency transformers in the PPU (Power Processing Unit), a crucial component of a space propulsion power supply, as research objects, accelerated electrical aging tests are conducted on the insulation structure design of high-voltage electronic components under vacuum and constant temperature conditions. The insulation failure lifetime and / or insulation state change trends under different voltage stresses are obtained. The electrical aging characteristics of different insulation structures are compared, analyzed, and evaluated, and electrical aging lifetime models for various insulation structures are established, providing a foundation for reliability testing and analysis methods for high-voltage electronic components.

[0034] The following section uses the high-voltage rectifier tube as an example to explain in detail the experimental process of obtaining its life model, and fits the life model of the satellite high-voltage electronic components based on the experimental results.

[0035] (I) Test Conditions

[0036] The high acceleration life test of the embodiments of the present application is a high acceleration life test under different electrical stresses in a vacuum and constant temperature condition.

[0037] In order to shorten the test time, the acceleration means of increasing the test voltage amplitude is adopted. In the test scheme, the applicant refers to the method of verifying the high-voltage insulation design margin and the method of high-voltage circuit component acceptance test described in the high-voltage engineering and design manual, and finally selects three voltage levels after many tests and researches, that is, respectively applying 3.0 times, 2.5 times and 2.1 times of the working voltage to the test sample. After the known voltage, the corresponding test time or average (or median) predicted life is not less than 100h, 600h and 2400h respectively according to the following model (formula 1).

[0038] When the power processing unit assembly bears high-frequency pulse voltage, its life is related to the amplitude and repetition frequency of the voltage. Within a certain temperature range, the life of the material follows the approximate formula (1).

[0039]

[0040] In the formula, t is the electrical life, A and b are constants, T is the temperature, U is the pulse voltage, n(T) is only related to the material and the temperature, and is a constant within a certain voltage range, which is determined by the insulation structure, process and aging factor, and f is the repetition frequency. P

[0041] The electrical, temperature and air pressure conditions in the basic test scheme are as follows.

[0042] 1) Voltage condition:

[0043] The high-frequency square wave working voltage of 3.0 times, 2.5 times and 2.1 times of the test sample is respectively taken, and the frequency is 50 kHz.

[0044] 2) Temperature condition: the constant temperature of the test environment is 70℃.

[0045] 3) Air pressure condition: the high acceleration life test and diagnostic test are carried out in a vacuum environment, and the air pressure of the test box is not more than 5×10 -3 Pa.

[0046] (II) Test sample preparation

[0047] The test sample is made according to the simulation of the actual insulation structure, and the number of test samples with the same insulation structure is 20, of which 15 are used for accelerated electrical aging test, and the remaining 5 are used for initial breakdown or other unaged comparison test. All test samples need to be dried in an 80℃ oven before the test, and the drying time is not less than 6 hours. The test sample structure is shown in Table 5-1.​

[0048] Table 1 Aging test samples

[0049]

[0050] (III) Test scheme

[0051] The test and diagnosis process includes four parts, i.e. cold-heat alternating cycle test, electrical accelerated aging test, non-destructive performance parameter detection, and destructive performance parameter detection, as shown in Figure 1

[0052] 1) Cold-heat alternating cycle test: Before the electrical accelerated aging test, 31 times of vacuum cold-heat alternating cycle test is first performed, and each cycle period is 8h, the temperature is at -35℃ and 90℃ for 2h respectively, and the time for temperature conversion is 4h.

[0053] 2) Electrical accelerated aging test: Under vacuum and 70℃ ambient temperature, electrical accelerated aging tests of 3.0 times, 2.5 times and 2.1 times working voltage are sequentially performed, and the corresponding electrical accelerated aging time is not less than 100h, 600h and 2400h respectively, and diagnosis test of the characteristic parameters related to the insulation state needs to be performed before and after the aging test or during the process. For the 3.0 times / 100h accelerated aging test, only the measurement of the aging characteristic parameters before and after 100h of aging is required; for the 2.5 times / 600h accelerated aging test, the measurement of the aging characteristic parameters is designed to be performed once every 300h; for the 2.1 times / 2400h accelerated aging test, the measurement of the aging characteristic parameters is designed to be performed once every 1200h.

[0054] 3) Non-destructive performance parameter detection: The dielectric properties of the test product should be measured before and after the electrical aging acceleration test and during the process, and the main test items include direct current insulation resistance and absorption ratio, power frequency dielectric loss factor and its increment, capacitance and its change, power frequency partial discharge starting voltage and appearance inspection, etc.

[0055] 4) Destructive performance parameter detection: The residual breakdown voltage of the test sample after the completion of 3.0 times, 2.5 times and 2.1 times electrical accelerated aging is measured, and the residual breakdown voltage is compared and analyzed with the breakdown voltage of each unaged comparative sample. In addition, the appearance morphology before and after the aging of each sample is compared, the microscopic observation of the breakdown point of the sample with obvious breakdown damage point is performed, and the breakdown position and the microscopic morphology change of the breakdown point are analyzed.

[0056] (IV) Test results and analysis

[0057] (1) Analysis of electrical accelerated aging test results

[0058] ​The high acceleration life test was carried out on four kinds of insulation structure samples of high-voltage rectifier tube (imported Dow Corning pouring, imported vacuum insulation, domestic Dow Corning pouring and domestic vacuum insulation), and the test results are as follows:

[0059] 1) After 100h high acceleration life test at 3.0 times working voltage, the possible insulation problems of four kinds of insulation structure samples of high-voltage rectifier tube are: low pressure small air gap exists at the pin of four kinds of high-voltage rectifier tube or low pressure small air gap will be generated at the high-voltage pin in the space vacuum operating environment.

[0060] 2) After 600h high acceleration life test at 2.5 times working voltage, the possible insulation problems of four kinds of insulation structure samples of high-voltage rectifier tube are: no air gap exists at the pin of two kinds of imported high-voltage rectifier tube, low pressure small air gap exists at the pin of two kinds of domestic high-voltage rectifier tube.

[0061] 3) After 2400h high acceleration life test at 2.1 times working voltage, the possible insulation problems of four kinds of insulation structure samples of high-voltage rectifier tube are: low pressure small air gap exists at the pin of two kinds of imported high-voltage rectifier tube or low pressure small air gap will be generated at the high-voltage pin in the space vacuum operating environment; coating delamination may occur in the imported vacuum insulation and domestic Dow Corning pouring high-voltage rectifier tube.

[0062] The evaluation results are shown in Tables 2, 3 and 4:

[0063] Table 2 Insulation state evaluation analysis results after 3.0 times voltage high acceleration test

[0064]

[0065] Table 3 Insulation state evaluation analysis results after 2.5 times voltage high acceleration test

[0066]

[0067] Table 4 Insulation state evaluation analysis results after 2.1 times voltage high acceleration test

[0068]

[0069] Note: ○—not failed, ×—failed.

[0070] (2) Analysis of destructive test results

[0071] At present, it is considered that only the breakdown voltage can reflect the real aging degree of insulation, that is, insulation withstand voltage test needs to be carried out at a higher voltage. In this study, the residual DC breakdown voltage of high-voltage rectifier tube under the accelerated aging voltage level was tested after all the aging tests were completed, so as to determine the aging degree of high-voltage rectifier tube and whether it is failed or not. As shown in Table 5-5, the breakdown voltage and aging failure of high-voltage rectifier tube under three accelerated voltage levels are shown.

[0072] As can be seen from Table 5, the residual DC breakdown voltage of high-voltage rectifier tube remains at a high level after 100h and 600h of aging under 3.0 times and 2.5 times of accelerated voltage, respectively, and no breakdown occurs. After 2400h of aging under 2.1 times of accelerated voltage, the residual DC breakdown voltage of high-voltage rectifier tube with two kinds of vacuum insulation is relatively obviously decreased compared with the non-aged comparative sample, and the residual breakdown voltage of the two is already lower than 50% of the initial breakdown voltage, indicating that the accelerated voltage aging for a long time has caused certain damage to the insulation of the high-voltage rectifier tube. In addition, by comparing the residual breakdown voltage of each device under three voltage levels with the breakdown voltage of the non-aged comparative sample, it is found that the residual breakdown voltage of some samples after aging is even higher than the breakdown voltage of the non-aged comparative sample. Combined with the simulation and test results described above, it is speculated that the main reason for this situation is that the manufacturing process of the high-voltage electronic components for spaceflight cannot maintain complete consistency, and some devices may have obvious uneven coating or sealing bubbles during the coating or sealing process in the manufacturing process.

[0073] Table 5 Residual breakdown voltage (kV) of high-voltage rectifier tube under three accelerated voltage levels

[0074] Assembly 3.0 times 2.5 times 2.1 times Comparative sample High voltage rectifier tube (Dow Corning potting / Import) 5.7 6.4 4.1 7.7 High voltage rectifier tube (Vacuum insulation / Import) >8.4 >9.3 1.4 3.8 High voltage rectifier tube (Dow Corning potting / China-made) 16.6 17 11.4 8.4 High voltage rectifier tube (Vacuum insulation / China-made) 15.3 16.8 4.3 19.4

[0075] Since no obvious damage and breakdown point is observed on each sample after aging, the microstructure of each layer of the insulation structure of each sample is no longer analyzed, including microscopic observation, infrared spectrum analysis, etc.

[0076] (Five) Fitting of the model

[0077] Since the acceleration aging factor of this test is only electric stress, a single-factor electric aging model is considered to be adopted, and formula 5-1 is the electric aging life prediction formula of insulation under the action of high-frequency pulse voltage. When the high-voltage electronic component bears high-frequency pulse voltage, its electric aging life is related to the amplitude and repetition frequency of the voltage, and within a certain temperature range, the material life follows the approximate formula (5-1).

[0078]

[0079] In the formula, t is the electric life; A and b are constants; T is the temperature; U pwhere V is the peak voltage amplitude, n(T) is a material and temperature dependent constant that is determined by the insulation structure, process and aging factors, and f is the repetition frequency.

[0080] By using the method of first test and then curve fitting, the high voltage rectifier tube, high voltage relay and high frequency transformer in PPU, which is an important part of the power supply of spaceflight thruster, are taken as the research objects. The potential failure risk of the insulation structure of these devices under the action of accelerated voltage aging is analyzed by simulation, and the reliability of the life of these devices under actual working conditions is evaluated according to the results of the aging test.

[0081] In the present accelerated aging test, the relationship between the pulse voltage and the life time of the insulation assembly is determined, and the evaluation is carried out at three voltage levels while keeping other conditions unchanged. Therefore, the relationship between the life and the voltage amplitude can be represented by an inverse power function,

[0082] L=kE -n (2)

[0083] In the formula, L is the failure time or failure frequency (at a given probability) of the sample, n is the voltage aging coefficient (VEC), k is a constant, and E is the voltage amplitude.

[0084] The working voltage of the sample under actual working conditions is represented as Un, and the multiple voltage applied in the accelerated aging test is represented as U. The life curve is plotted on the double logarithmic coordinate graph, and the relationship curve between the withstand voltage multiple (U / Un) of the insulation system and the aging time t (h) under the acceleration condition considering only the voltage amplitude is shown by the red straight line in Figure 2 ,

[0085] The expression is formula (3):

[0086]

[0087] In the formula, L is the expected life of the high-voltage electronic assembly, U / U n is the voltage acceleration multiple, n is the voltage aging coefficient (VEC), and k is a constant.

[0088] According to the test results, the relationship between the withstand voltage multiple (U / Un) of the insulation system of the satellite high-voltage electronic assembly and the aging time t (h) is analyzed, the relationship curve is obtained, the insulation life model of the satellite high-voltage electronic assembly is fitted, the electrical aging life model of the insulation structure of the satellite high-voltage electronic assembly is established, and the insulation life of the high-voltage electronic assembly can be evaluated by selecting the safety margin coefficient of the high-voltage electronic assembly.

[0089] Application calculation of the model:

[0090] The high acceleration life test of high voltage rectifier tubes with four insulation structures is carried out under vacuum and 70 ℃ ambient temperature with high voltage of 3.0 times, 2.5 times and 2.1 times, and the relationship curve and model between the withstanding voltage multiple and the life are fitted according to the test results, which provides support for the life evaluation of high voltage electronic components. For example, the safety margin coefficient of high voltage electronic components is usually 1.2-1.5, when it is 1.3, the insulation life evaluation value of 1.3Un can be obtained as 185895 h, i.e. 21 years, according to the above curve ( Figure 2 ) and model (formula 3).

[0091] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for calculating a lifetime model of a satellite high-voltage electronic assembly, characterized in that, The specific process is: Setting experimental conditions: performing high-accelerated life test under different electric stresses under vacuum and constant temperature conditions, and determining the test time corresponding to each applied working voltage; Test sample preparation: the sample is made according to the simulation of the actual insulation structure, and high-temperature drying is performed before the test; Test scheme: including cold and hot alternating cycle test, electric accelerated aging test and non-destructive performance parameter detection; The cold and hot alternating cycle test: performing multiple vacuum cold and hot alternating cycle tests, each cycle period T hours, each lasting T / 4 hours at low and high temperatures, and the two temperature conversion times are T / 4 hours; The electric accelerated aging test: in the set vacuum environment and temperature, sequentially performing electric accelerated aging tests of different working voltages, and the electric accelerated aging time under each working voltage is not less than the corresponding set time; The non-destructive performance parameter detection is: measuring the dielectric properties of the test product before and after the electric aging acceleration test and during the aging process, and when the diagnostic test determines that the test piece fails, the aging test is stopped; Model fitting: based on the performance parameters obtained by non-destructive performance parameter detection, fitting the relationship curve between the withstand voltage multiple and the life, obtaining the fitting coefficient, and obtaining the satellite high-voltage electronic component life model based on the fitting coefficient.

2. The method of claim 1, wherein the method further comprises: The fitting relationship curve between the withstand voltage multiple and the life is obtained, and the fitting coefficient is: Wherein, L is the expected life of the high-voltage electronic assembly; is the voltage acceleration factor; n and K are coefficients to be fitted.

3. The method of claim 1, wherein the method further comprises: Before performing the test scheme, the temperature for drying the selected test is 80 DEG C, and the time is not less than 6 hours.

4. The method of claim 2, wherein the method further comprises: In the setting experimental conditions, three voltage levels are selected, i.e. 3.0 times, 2.5 times and 2.1 times of the working voltage are applied to the sample, and the test time of 3.0 times, 2.5 times and 2.1 times of the working voltage is not less than 100h, 600h and 2400h respectively; for 3.0 times / 100h accelerated aging test, only the measurement of aging characteristic parameters before and after 100h of aging is required; for 2.5 times / 600h accelerated aging test, the measurement of aging characteristic parameters is designed to be performed once every 300h; for 2.1 times / 2400h accelerated aging test, the measurement of aging characteristic parameters is designed to be performed once every 1200h; during the parameter test, when it is determined according to the measurement result that the test piece has failed, the test of the test piece is ended.

5. The method of claim 1, wherein the method further comprises: The test scheme also includes destructive performance parameter detection, and the destructive performance parameter detection is: for the test piece that has completed the set time of accelerated aging test and has not failed, the measurement of the remaining breakdown voltage is performed, and the remaining breakdown voltage is compared and analyzed with the breakdown voltage of each unaged comparative sample.

6. The method of claim 1, wherein the method further comprises: The vacuum and constant temperature conditions are: the constant temperature of the test environment is 70℃; the high acceleration life test and the diagnostic test are carried out in a vacuum environment, and the air pressure of the test box is not more than 5×10 -3 Pa.

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