Method for evaluating residual life of electrical component under influence of stress fluctuation

Abstract

The invention discloses a method for evaluating the residual life of an electrical component under the influence of stress fluctuation, and the method comprises the steps: firstly, obtaining the initial state information of the electrical component, including characteristic parameters and initial values thereof; then, a static artificial accelerated aging corrosion test is carried out, and the change value of the characteristic parameters along with time is obtained; based on the change values, the basic weight of each characteristic parameter is determined. And establishing a function relation between the characteristic parameters and time, and describing the aging process. An Arrhenius model is used to calculate an acceleration factor, and the model is adjusted to adapt to different temperature conditions. And obtaining a characteristic parameter degradation model according to the acceleration factor and the function relation. And when the electrical component is only influenced by the environmental stress fluctuation, further establishing a degradation model considering the influence. Finally, according to the operation state of the electrical component, the residual life is evaluated by using a corresponding model, and a scientific basis is provided for maintenance and management. According to the method, various factors are comprehensively considered, the evaluation accuracy is improved, and the system reliability and safety are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of predicting the remaining life of electrical equipment, and particularly relates to a method for evaluating the remaining life of electrical components under the influence of stress fluctuations. Background Art

[0002] In modern electronic devices, the reliability and life evaluation of electrical components are of extremely important significance. With the continuous progress of technology, electrical components play a key role in various complex application scenarios, and the stability of their performance and the length of their life are directly related to the reliability and safety of the entire system. Accurately evaluating the remaining life of electrical components can not only optimize the equipment maintenance plan, reduce maintenance costs, but also effectively prevent system failures caused by component failures and ensure the normal operation of the equipment. In addition, under the background of circular economy, the evaluation of the remaining life of electrical and electronic product components has important practical significance for the remanufacturability evaluation of old products, the evaluation of the ecological efficiency of product systems, and the market access and supervision of old products by the government.

[0003] However, the existing methods for evaluating the remaining life of electrical components have many limitations. Specifically, most of the existing evaluation methods focus on life prediction under storage conditions and design margins, often ignoring the interference of numerous internal and external stress fluctuations on the remaining life of electrical components during actual use, which results in a large error in life evaluation and limited guidance for actual production. For example, although the traditional accelerated life test method can obtain the failure rate and life of components under normal use conditions in a short time, the accuracy of its extrapolation results may be affected by the large difference between the applied harsh environment or stress and the actual use conditions. The reliability evaluation method based on performance degradation data can predict the life using different process models according to different failure modes, but when facing the complex failure mechanism of electrical components and the coupling effect of multiple stress factors, a single performance degradation model is difficult to accurately describe the actual degradation process of the components.

[0004] In summary, the current methods for evaluating the remaining life of electrical components still need to be further improved in terms of applicability and the accuracy of prediction results. Summary of the Invention

[0005] The object of the present invention is to solve the above technical problems and provide a method for evaluating the remaining life of electrical components under the influence of stress fluctuations, which can more accurately evaluate the remaining life of electrical components.

[0006] To solve the above problems, the present invention is implemented according to the following technical solutions:

[0007] The present invention provides a method for evaluating the remaining life of electrical components under the influence of stress fluctuations, and the method includes the following steps:

[0008] S100. Obtain the initial state information of the electrical component to be evaluated, where the initial state information includes the characteristic parameters of the electrical component to be evaluated and the initial values of the characteristic parameters;

[0009] S200. Conduct a static artificial accelerated aging and corrosion test on the electrical component to be evaluated, and obtain the change values of the characteristic parameters over time;

[0010] S300. Based on the change values of the characteristic parameters over time, determine the basic weight ω of each characteristic parameter i ;

[0011] S400. Establish a functional relationship between the value of each characteristic parameter obtained during the static artificial accelerated aging and corrosion test and time, and the functional relationship is y i = f i (t), where t represents the duration of the static artificial accelerated aging and corrosion test;

[0012] S500. Calculate the acceleration factor AF according to the Arrhenius model , where F is the reaction rate constant, A is the frequency factor, E a is the activation energy of the electrical component to be evaluated, k is the Boltzmann constant, and T is the absolute temperature;

[0013] S600. Obtain the characteristic parameter degradation model of the electrical component to be evaluated according to the acceleration factor AF and the functional relationship in step S400

[0014] S700. When the electrical component to be evaluated is only affected by environmental stress fluctuations during actual use, establish a characteristic parameter degradation model considering the influence of environmental stress fluctuations [B]=∑ω i B i =∑ω i f i (t,α 1 ,α 2 ,α 3 ,...,α k ), where the α 1 ,α 2 ,α 3 ,...,α k are the environmental stress fluctuation influence factors affecting the electrical component to be evaluated;

[0015] S800. When the electrical component to be evaluated is in a non-operating state, evaluate the remaining life of the electrical component to be evaluated through the characteristic parameter degradation model [A], and the evaluated remaining life is denoted as Y A; When the electrical component to be evaluated is only affected by environmental stress fluctuations during actual operation, the number of years Y of depreciation of the electrical component to be evaluated due to environmental stress fluctuations is calculated through the characteristic parameter degradation model [B] B , then the actual remaining life Y of the electrical component to be evaluated at this time 1 = Y A - Y B .

[0016] Preferably, the specific process of step S300 includes:

[0017] S310. Assume that there are m characteristic parameters, and the observed values of each characteristic parameter at different time points are x ij , where i is the time point, j is the index of the characteristic parameter, and n is the number of observed values of each characteristic parameter;

[0018] S320. Normalize the observed values x ij of each characteristic parameter at different time points, and calculate the normalized value p ij ;

[0019] S330. Calculate the information entropy E ij of each characteristic parameter according to the normalized value p j ;

[0020] S340. Calculate the basic weight ω j of each characteristic parameter according to the information entropy E i .

[0021] Preferably, in step S320, the normalized value

[0022] Preferably, in step S330, the information entropy

[0023] Preferably, in step S340, the basic weight

[0024] Preferably, in step S500, the acceleration factor where T 0 is the absolute temperature in the normal state, and T test is the absolute temperature in the accelerated state.

[0025] Preferably, step S700 further includes: when the electrical component to be evaluated is only affected by working stress fluctuations during actual use, establish a characteristic parameter degradation model [C] considering the influence of working stress fluctuations = ∑ω i C i = ∑ω i f i (t, β 1, β 2 , β 3 ,..., β k ), where the β 1 , β 2 , β 3 ,..., β k is the working stress fluctuation influence factor affecting the electrical component to be evaluated.

[0026] Preferably, when the electrical component to be evaluated is only affected by working stress fluctuations during actual operation, the number of years Y of wear and tear of the electrical component to be evaluated due to environmental stress fluctuations is calculated through the characteristic parameter degradation model [C] C , then the actual remaining life Y of the electrical component to be evaluated at this time 2 = Y A - Y C .

[0027] Preferably, step S700 further includes: when the electrical component to be evaluated is affected by multiple stress fluctuations during actual use, a characteristic parameter degradation model [D] considering the influence of multiple stress fluctuations is established = ∑ω i D i = ∑ω i f i (t, θ 1 , θ 2 , θ 3 ,..., θ k ), where the θ 1 , θ 2 , θ 3 ,..., θ k are the multiple stress fluctuation influence factors affecting the electrical component to be evaluated.

[0028] Preferably, when the electrical component to be evaluated is affected by multiple stress fluctuations during actual operation, the number of years Y of wear and tear of the electrical component to be evaluated due to multiple stress fluctuations is calculated through the characteristic parameter degradation model [D] D , then the actual remaining life Y of the electrical component to be evaluated at this time 3 = Y A - Y D .

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] The present invention provides a method for evaluating the remaining life of electrical components under the influence of stress fluctuations. First, the present invention obtains the initial state information of the electrical components to be evaluated, including characteristic parameters and their initial values, providing the basic data for subsequent evaluation. Then, through a static artificial accelerated aging and corrosion test, the change values of the characteristic parameters over time are obtained, and these data are used to determine the basic weights of each characteristic parameter, thereby reflecting the relative importance of each characteristic parameter in the life evaluation of electrical components. By calculating the information entropy and the basic weights, the present invention can more accurately evaluate the influence of characteristic parameters on the life of electrical components.

[0031] Furthermore, the present invention establishes a functional relationship between the characteristic parameters and time, and calculates the acceleration factor according to the Arrhenius model, thereby obtaining the degradation model of the characteristic parameters of the electrical components. This model not only considers the influence of the temperature acceleration factor, but also establishes a more comprehensive degradation model by considering the environmental stress fluctuation influence factor. When the electrical components are affected by environmental stress fluctuations, working stress fluctuations or multiple stress fluctuations during actual use, the present invention can calculate the actual remaining life of the electrical components through the corresponding degradation model, providing a more accurate and reliable evaluation result.

[0032] In summary, the present invention is applicable not only to the evaluation of the remaining life under simple conditions, but also to the evaluation of the remaining life of electrical components under complex conditions. By assigning reasonable weight ratios to the characteristic parameters, the present invention can more deeply understand the working mechanism of the electrical components and provide relatively accurate prediction results. In addition, the present invention can also comprehensively understand and optimize the performance of electrical components throughout their entire life cycle, support the establishment of a more effective health monitoring system for industrial systems, timely detect abnormal conditions and warn of possible upcoming failures, thereby ensuring the reliability and safety of electrical components. This not only improves the accuracy of the evaluation, but also provides strong technical support for the maintenance and asset management of industrial systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The following further describes in detail the specific embodiments of the present invention with reference to the drawings, wherein:

[0034] Figure 1 is the technical principle diagram of a method for evaluating the remaining life of electrical components under the influence of stress fluctuations according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0036] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. Unless otherwise defined, the technical terms or scientific terms used in this specification should have the ordinary meaning understood by those of ordinary skill in the art to which this application belongs. The "first", "second" and similar terms used in this specification and the claims do not denote any order, quantity or importance, but are only used to distinguish different technical features.

[0037] The following is an illustration of the preferred embodiments of the present invention. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present invention and are not used to limit the present invention.

[0038] A method for evaluating the remaining life of an electrical component applicable under the influence of stress fluctuations according to the present invention includes the following steps:

[0039] S100. Obtain the initial state information of the electrical component to be evaluated, where the initial state information includes the characteristic parameters of the electrical component to be evaluated and the initial values of the characteristic parameters;

[0040] It can be understood that these initial state information provide basic data for subsequent evaluations, ensuring that the starting point of the evaluation is accurate and reliable. In this embodiment, the characteristic parameters refer to various indicators that can reflect the performance and state of the electrical component, such as capacitance value, leakage current, equivalent series resistance, etc. The initial values of the characteristic parameters are the measured values of these parameters in the brand-new or initial state of the electrical component, providing a benchmark for subsequent changes.

[0041] S200. Conduct a static artificial accelerated aging and corrosion test on the electrical component to be evaluated to obtain the change of the characteristic parameters over time;

[0042] It should be noted that the static artificial accelerated aging corrosion test means that the electrical component to be evaluated undergoes an artificial accelerated aging corrosion test while being in a non-operating or unpowered load state throughout the process. This can obtain the aging corrosion change law of the electrical equipment within a relatively short test cycle, obtain the cumulative damage amount information of the electrical component under a relatively short time series, and obtain the normal life of the electrical component in the actual environment by comparing the artificial accelerated aging test conditions with the actual environmental conditions. Among them, the normal life refers to the life of the electrical component in a non-operating state without stress fluctuations, that is, close to the storage life of the electrical component. In this embodiment, the change values of the characteristic parameters over time are obtained through the static artificial accelerated aging corrosion test, and these change values are crucial for understanding the performance degradation that the electrical component may experience during actual use, providing experimental data support for establishing a degradation model later.

[0043] S300. Based on the change values of the characteristic parameters over time, determine the basic weight ω of each characteristic parameter i ;

[0044] Specifically, S310. Assume that there are m of these characteristic parameters, and the observed values of each characteristic parameter at different time points are x ij , where i is the time point, j is the index of the characteristic parameter, and n is the number of observed values of each characteristic parameter;

[0045] Furthermore, S320. Normalize the observed values x ij of each characteristic parameter at different time points, and calculate the normalized value p ij . Specifically,

[0046] Furthermore, S330. Calculate the information entropy E of each characteristic parameter according to the normalized value p ij , specifically, j .

[0047]

[0048] Furthermore, S340. Calculate the basic weight ω of each characteristic parameter according to the information entropy E j , specifically, i .

[0049]

[0050] It can be understood that information entropy is an index to measure the uncertainty of data. The smaller its value, the more the change of this characteristic parameter can reflect the degradation of the electrical component. Therefore, a higher weight should be assigned. By calculating the information entropy to quantify the basic weight of each characteristic parameter, it can be ensured that in the comprehensive evaluation, the more important characteristic parameters have a greater impact on the final result.

[0051] S400. Establish a functional relationship between the value of each characteristic parameter obtained during the static artificial accelerated aging corrosion test and time. This functional relationship is y i = f i (t), where t represents the duration of the static artificial accelerated aging corrosion test;

[0052] It can be understood that this functional relationship describes the variation law of the characteristic parameter with time, which is crucial for predicting the expected value of the characteristic parameter at a given time point and then inferring the current state and future performance of the electrical component.

[0053] S500. Calculate the acceleration factor AF according to the Arrhenius model , where F is the reaction rate constant, A is the frequency factor, E a is the activation energy of the electrical component to be evaluated, k is the Boltzmann constant, and T is the absolute temperature;

[0054] It should be noted that the Arrhenius model is an empirical formula describing the relationship between the reaction rate and temperature of a chemical reaction. It is used here to quantify the influence of temperature on the aging rate of electrical components. The acceleration factor AF reflects the difference in the aging rate of electrical components under different temperature conditions. By calculating this factor, the data in the accelerated test can be extrapolated to the expected life under actual use conditions.

[0055] Specifically, where T 0 is the absolute temperature in the normal state, and T test is the absolute temperature in the accelerated state;

[0056] It should be noted that in this embodiment, (1) the relationship between the reaction rate constant F and the temperature T is as follows: In the normal state, when the electrical component to be evaluated is working, the absolute temperature is T 0 , and the reaction rate constant is F 0 , then In the accelerated state, when the electrical component to be evaluated is working, the absolute temperature is T test , and the reaction rate constant is F test , then (2) To find the ratio of the rate constants at these two temperatures, we take the ratio of the two equations: Among them, since the frequency factor A is a constant and can be canceled out, this ratio can be simplified to: (3) The reaction rate constant F is inversely proportional to the life L of the electrical component to be evaluated. Therefore: That is (4) The acceleration factor AF is the ratio of the life of the electrical component to be evaluated under normal working conditions to the life under accelerated test conditions:

[0057] That is

[0058] S600. Obtain the characteristic parameter degradation model of the electrical component to be evaluated according to the acceleration factor AF and the functional relationship in step S400

[0059] S700. When the electrical component to be evaluated is only affected by environmental stress fluctuations during actual use, establish a characteristic parameter degradation model considering the influence of environmental stress fluctuations [B] = ∑ω i B i = ∑ω i f i (t, α 1 , α 2 , α 3 ,..., α k ), where α 1 , α 2 , α 3 ,..., α k are the environmental stress fluctuation influence factors affecting the electrical component to be evaluated;

[0060] Preferably, step S700 further includes: when the electrical component to be evaluated is only affected by working stress fluctuations during actual use, establish a characteristic parameter degradation model considering the influence of working stress fluctuations [C] = ∑ω i C i = ∑ω i f i (t, β 1 , β 2 , β 3 ,..., β k ), where β 1 , β 2 , β 3 ,..., β k are the working stress fluctuation influence factors affecting the electrical component to be evaluated;

[0061] Preferably, step S700 further includes: when the electrical component to be evaluated is affected by multiple stress fluctuations during actual use, establish a characteristic parameter degradation model considering the influence of multiple stress fluctuations [D] = ∑ω i D i = ∑ω i f i (t, θ 1 , θ 2 , θ 3 ,..., θ k ), where θ 1 , θ 2 , θ 3 ,..., θ kis the multiple stress fluctuation influence factor affecting the electrical component to be evaluated;

[0062] S800. When the electrical component to be evaluated is in a non-operating state, the remaining life of the electrical component to be evaluated is evaluated through the characteristic parameter degradation model [A], and the evaluated remaining life is denoted as Y A ; when the electrical component to be evaluated is only affected by environmental stress fluctuations during actual operation, the number of years Y damaged by environmental stress fluctuations of the electrical component to be evaluated is calculated through the characteristic parameter degradation model [B] B , then the actual remaining life Y of the electrical component to be evaluated at this time 1 = Y A - Y B .

[0063] In one embodiment, when the electrical component to be evaluated is only affected by working stress fluctuations during actual operation, the number of years Y damaged by environmental stress fluctuations of the electrical component to be evaluated is calculated through the characteristic parameter degradation model [C] C , then the actual remaining life Y of the electrical component to be evaluated at this time 2 = Y A - Y C ;

[0064] In one embodiment, when the electrical component to be evaluated is affected by multiple stress fluctuations during actual operation, the number of years Y damaged by multiple stress fluctuations of the electrical component to be evaluated is calculated through the characteristic parameter degradation model [D] D , then the actual remaining life Y of the electrical component to be evaluated at this time 3 = Y A - Y D .

[0065] The beneficial effects of the present invention are:

[0066] The present invention provides a method for evaluating the remaining life of an electrical component under the influence of stress fluctuations. First, the present invention provides basic data for subsequent evaluation by obtaining the initial state information of the electrical component to be evaluated, including characteristic parameters and their initial values. Then, through a static artificial accelerated aging and corrosion test, the change values of the characteristic parameters over time are obtained, and these data are used to determine the basic weights of each characteristic parameter, thereby reflecting the relative importance of each characteristic parameter in the life evaluation of the electrical component. By calculating the information entropy and the basic weights, the present invention can more accurately evaluate the influence of the characteristic parameters on the life of the electrical component.

[0067] Furthermore, the present invention establishes a functional relationship between characteristic parameters and time, calculates the acceleration factor according to the Arrhenius model, and thus obtains a degradation model of the characteristic parameters of the electrical component. This model not only considers the influence of the temperature acceleration factor, but also establishes a more comprehensive degradation model by considering the influence factor of environmental stress fluctuation. When the electrical component is affected by environmental stress fluctuation, working stress fluctuation or multiple stress fluctuations during actual use, the present invention can calculate the actual remaining life of the electrical component through the corresponding degradation model, providing a more accurate and reliable evaluation result.

[0068] In summary, the present invention is applicable not only to the remaining life assessment under simple conditions, but also to the remaining life assessment of electrical components under complex conditions. By assigning reasonable weight ratios to the characteristic parameters, the present invention can more deeply understand the working mechanism of the electrical components and provide relatively accurate prediction results. In addition, the present invention can also comprehensively understand and optimize the performance of the electrical components throughout their entire life cycle, support the establishment of a more effective health monitoring system for industrial systems, timely detect abnormal conditions and warn of possible impending failures, thereby ensuring the reliability and safety of the electrical components. This not only improves the accuracy of the assessment, but also provides strong technical support for the maintenance and asset management of industrial systems.

[0069] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Therefore, any modifications, equivalent changes and decorations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for evaluating the remaining life of electrical components under the influence of stress fluctuations, characterized in that: The method comprises the following steps: S100, obtaining initial state information of the electrical component to be evaluated, wherein the initial state information includes characteristic parameters of the electrical component to be evaluated and initial values ​​of the characteristic parameters; S200, conducting a static artificial accelerated aging corrosion test on the electrical component to be evaluated to obtain a change value of the characteristic parameter over time; S300: Determine a basic weight ω of each characteristic parameter based on the change value of the characteristic parameter over time. i ; S400, establishing a functional relationship between the value of each characteristic parameter obtained during the static artificial accelerated aging corrosion test and time, wherein the functional relationship is y i =f i (t), wherein t represents the duration of the static artificial accelerated aging corrosion test; S500, according to the Arrhenius model The acceleration factor AF is calculated, where F is the reaction rate constant, A is the frequency factor, and E is a is the activation energy of the electrical component to be evaluated, k is the Boltzmann constant, and T is the absolute temperature; S600: Obtain the characteristic parameter degradation model of the electrical component to be evaluated according to the acceleration factor AF and the functional relationship in step S400. S700, when the electrical component to be evaluated is only affected by environmental stress fluctuations in actual use, a characteristic parameter degradation model [B]=∑ω is established that takes into account the influence of environmental stress fluctuations i B i =∑ω i f i (t,α1,α2,α3,...,α k ), wherein the α1, α2, α3, ..., α k The environmental stress fluctuation influencing factor affecting the electrical component to be evaluated; S800: When the electrical component to be evaluated is in a non-operating state, the remaining life of the electrical component to be evaluated is evaluated by using a characteristic parameter degradation model [A], and the estimated remaining life is recorded as Y A When the electrical component to be evaluated is only affected by environmental stress fluctuations in actual work, the age Y of the electrical component to be evaluated due to environmental stress fluctuations is calculated by the characteristic parameter degradation model [B] B , then the actual remaining life of the electrical component to be evaluated is Y1=Y A -Y B .

2. A method for evaluating the remaining life of an electrical component under the influence of stress fluctuations according to claim 1, characterized in that: The specific process of step S300 includes: S310, assuming that there are m characteristic parameters, and the observed value of each characteristic parameter at different time points is x ij , where i is a time point, j is an index of a characteristic parameter, and n is the number of observations of each characteristic parameter; S320, the observed value x of each characteristic parameter at different time points ij Perform normalization and calculate the normalized value p ij ; S330, according to the normalized value p ij Calculate the information entropy E for each feature parameter j ; S340, according to information entropy E j Calculate the base weight ω of each feature parameter i .

3. The method for evaluating the remaining life of an electrical component under the influence of stress fluctuation according to claim 2, characterized in that: In step S320, the normalized value 4. The method for evaluating the remaining life of an electrical component under the influence of stress fluctuation according to claim 2, characterized in that: In step S330, information entropy 5. The method for evaluating the remaining life of an electrical component under the influence of stress fluctuation according to claim 2, characterized in that: In step S340, the basic weight 6. The method for evaluating the remaining life of an electrical component under the influence of stress fluctuation according to claim 1, characterized in that: In step S500, the acceleration factor Wherein, T0 is the absolute temperature under normal conditions, T test is the absolute temperature under accelerated conditions.

7. The method for evaluating the remaining life of an electrical component under the influence of stress fluctuation according to claim 1, characterized in that: Step S700 also includes: When the electrical component to be evaluated is only affected by working stress fluctuations in actual use, a characteristic parameter degradation model [C] = ∑ω is established considering the influence of working stress fluctuations. i C i =∑ω i f i (t,β1,β2,β3,...,β k ), where the β1, β2, β3,...,β k It is the working stress fluctuation influencing factor that affects the electrical component to be evaluated.

8. The method for evaluating the remaining life of an electrical component under the influence of stress fluctuation according to claim 7, characterized in that: When the electrical component to be evaluated is only affected by working stress fluctuations in actual work, the age Y of the electrical component to be evaluated that is damaged by environmental stress fluctuations is calculated by the characteristic parameter degradation model [C] C , then the actual remaining life of the electrical component to be evaluated is Y2 = Y A -Y C .

9. The method for evaluating the remaining life of an electrical component under the influence of stress fluctuation according to claim 1, characterized in that: Step S700 also includes: When the electrical component to be evaluated is affected by multiple stress fluctuations in actual use, a characteristic parameter degradation model [D] = ∑ω is established considering the influence of multiple stress fluctuations. i D i =∑ω i f i (t,θ1,θ2,θ3,...,θ k ), where the θ1, θ2, θ3,...,θ k It is the multiple stress fluctuation influencing factors that affect the electrical component to be evaluated.

10. A method for evaluating the remaining life of an electrical component under the influence of stress fluctuations according to claim 9, characterized in that: When the electrical component to be evaluated is affected by multiple stress fluctuations in actual work, the age Y of the electrical component to be evaluated that is damaged by multiple stress fluctuations is calculated by the characteristic parameter degradation model [D]. D , then the actual remaining life of the electrical component to be evaluated is Y3 = Y A -Y D .

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