CN-122017382-A - Method and system for evaluating service life of inductor

CN122017382ACN 122017382 ACN122017382 ACN 122017382ACN-122017382-A

Abstract

The invention provides a service life assessment method and a service life assessment system for an inductor, which relate to the technical field of measuring electric variables, and the invention utilizes a differential measurement mode to capture and compensate common mode errors of a measurement system introduced by environmental stress in real time by introducing a self-calibration test fixture of an integrated datum reference path, so that the problem of measurement errors introduced by aging of the test system is solved, thereby effectively separating fixture degradation from real performance attenuation of the inductor to be measured, and ensuring high fidelity of an acquired electric performance first data set; by calculating the physical electrical residual vector between the high-precision measured data and the predicted electrical performance data set, a diagnosis indication signal truly reflecting an unmodeled failure mechanism can be generated, and then the closed-loop feedback optimizing module is driven to execute accurate self-adaptive adjustment operation, so that the whole evaluation method is finally free from system error interference, and the residual service life prediction result with high scientificity and engineering application reliability is output.

Inventors

CAI SHANGLIN
CAI JINGZHANG
WANG QIGEN
ZHANG SHUJUAN

Assignees

岑科科技(深圳)集团有限公司

Dates

Publication Date: 20260512
Application Date: 20251212

Claims (10)

1. The method and the system for evaluating the service life of the inductor are characterized by comprising the following specific steps: synchronously acquiring the inductor to be tested under the stress environment while applying preset electric excitation: A first data set for representing the actual electrical performance of the inductor to be tested and a second data set for representing the internal physical state of the inductor to be tested; generating a predicted electrical performance data set of the inductance to be measured by using the second data set based on a preset multi-physical field coupling model for mapping the internal physical state to the electrical performance; calculating residual errors between the first data set and the predicted electrical performance data set to quantify deviation between actual electrical performance and predicted electrical performance of the inductor to be tested; Identifying the current dominant failure mechanism of the inductor to be tested based on the characteristics of the residual error, and generating a diagnosis indication signal representing the dominant failure mechanism; and step five, responding to the diagnosis indication signal, and executing self-adaptive adjustment operation, wherein the self-adaptive adjustment operation comprises the following steps: And adjusting the type of stress applied to the inductor to be tested, and updating a prediction model for predicting the residual service life of the inductor to be tested.
2. The method for evaluating the service life of an inductor according to claim 1, wherein the first step comprises the steps of: Applying preset electric excitation to the inductance to be tested in a stress environment, and simultaneously carrying out differential measurement through a self-calibration test fixture integrating a reference channel parallel to the inductance to be tested so as to calibrate in real time and obtain the first data set for representing the actual electrical performance of the inductance to be tested; Synchronously acquiring physical characteristic parameters for reflecting the health degree of the internal structure of the inductor to be detected by adopting a non-contact physical field imaging mode as the second data set; the non-contact physical field imaging mode comprises capturing transient thermal response of an inductor to be tested when responding to power pulse excitation by adopting a high-speed thermal infrared imager and drawing a near-field magnetic field space distribution diagram by adopting a three-dimensional magnetic field probe array.
3. The method for evaluating the service life of an inductor according to claim 2, wherein the second step comprises the steps of: using physical characteristic parameters in the second data set as input of a pre-established parameterized reduced multi-physical field coupling model, wherein the multi-physical field coupling model maps the physical characteristic parameters to corresponding electrical performance parameters, so as to generate a predicted electrical performance data set of the inductance to be measured; The multi-physical field coupling model is obtained by carrying out high-fidelity finite element simulation on the inductance to be tested in an off-line stage, scanning different physical damage degrees and working condition parameter combinations in the simulation, recording corresponding electrical performance responses, and finally fitting an analytic function which is obtained by a model reduction technology trained by a neural network and is used for carrying out real-time calculation.
4. The method for evaluating the service life of an inductor according to claim 3, wherein the second step further comprises: The internal physical state parameters input by the multi-physical field coupling model comprise interface thermal resistance extracted from transient thermal response and magnetic field distribution entropy extracted from near-field magnetic distribution, the predicted electrical performance data set output by the multi-physical field coupling model comprises a predicted inductance value, and the specific calculation flow is decomposed as follows: Taking the inductance nominal value as a reference, and then subtracting the inductance attenuation caused by thermal degradation and magnetic degradation in sequence to obtain a corrected prediction result, namely a predicted inductance value.
5. The method for evaluating the service life of an inductor according to claim 4, wherein the third step comprises the steps of: Calculating a multi-dimensional physical electric residual vector for synchronously quantifying the prediction accuracy of the multi-physical field coupling model in a plurality of electric performance dimensions, wherein each component of the physical electric residual vector is respectively defined as the difference between the actual electric performance parameter in the first data set and the theoretical predicted performance in the predicted electric performance data set; the step of calculating the physical electrical residual vector further comprises recording and storing a historical track, in particular a historical track of the physical electrical residual vector evolving along with time, so as to provide a data base for identifying the time evolution trend of the failure mechanism in the subsequent step.
6. The method for evaluating the service life of an inductor according to claim 5, wherein the fourth step comprises the steps of: the method comprises the steps of mapping physical electric residual vectors into a preset two-dimensional failure characteristic space formed by mutually orthogonal failure mode base vectors, determining the contribution degree of different failure modes to current performance deviation by calculating projection components of the physical electric residual vectors on each failure mode base vector, and generating a diagnosis indication signal capable of quantifying the current dominant failure mechanism according to the contribution degree.
7. The method for evaluating the service life of an inductor according to claim 6, wherein the fourth step further comprises: The failure mode base vectors are determined in advance through carrying out an accelerated aging test and failure physical analysis on the inductance with the same model as the inductance to be tested, wherein one base vector points to the fatigue of a welding spot or the oxidation failure mode direction of a terminal, which is mainly characterized by the increase of equivalent series resistance, and the other base vector points to the aging or structural cracking failure mode direction of a magnetic core material, which is mainly characterized by the decrease of inductance; The diagnosis indication signal is an failure mode deviation index, and the calculation flow of the failure mode deviation index specifically comprises the following steps: Comparing the actual inductance value of the inductance to be measured, which is measured in real time in the first data set through the self-calibration test fixture, with the theoretical inductance value predicted by the multi-physical field coupling model in the second data set, and defining the difference between the actual inductance value and the theoretical inductance value as an inductance residual; Dividing the absolute value of the inductance residual by a preset inductance failure threshold to obtain a normalized inductance residual, dividing the absolute value of the resistance residual contribution by a preset resistance failure threshold to obtain a normalized resistance residual, defining the normalized resistance residual as the resistance residual contribution to represent the severity of a welding spot fatigue failure mode, defining the normalized inductance residual as the inductance residual contribution to represent the severity of a magnetic core degradation failure mode, and determining the absolute value of the resistance residual contribution to represent the severity of the welding spot fatigue failure mode; and dividing the difference value obtained by subtracting the inductance residual contribution from the resistance residual contribution by the sum of the resistance residual contribution and the inductance residual contribution to obtain the failure mode deflection index.
8. The method for evaluating the service life of an inductor according to claim 7, wherein the fifth step comprises the steps of: performing an adaptive adjustment operation in response to the diagnostic indication signal by mapping a value of the diagnostic indication signal to a decision matrix of a preset association failure mechanism and test strategy; The decision matrix is preset with optimal stress combinations corresponding to different numerical intervals of the diagnosis indication signals, wherein the optimal stress combinations comprise the amplitude and the frequency of the temperature cycle are increased when the diagnosis indication signals indicate that the welding spots are mainly tired, and the magnitude of the direct current bias current is increased when the indication magnetic core is mainly aged.
9. The method for evaluating the service life of an inductor according to claim 8, wherein the fifth step further comprises: The decision matrix is to selectively perform at least one of: 1. Outputting a stress adjustment instruction to dynamically change the type or strength of stress applied to the inductor to be tested, so as to accelerate aging aiming at the failure mechanism which is currently dominant; 2. From a model library comprising a plurality of failure mode-specific degradation models, a degradation model matching the dominant failure mechanism characterized by the diagnostic indication signal is selected to update a prediction model for predicting its remaining useful life.
10. An inductor life assessment system, characterized in that the system is configured to perform an inductor life assessment method according to any one of claims 1-9, comprising: The multi-mode data synchronization module is used for synchronously acquiring the inductance to be tested under the stress environment while applying preset electric excitation: A first data set for representing the actual electrical performance of the inductor to be tested and a second data set for representing the internal physical state of the inductor to be tested; The physical model deduction module is used for generating a predicted electrical performance data set of the inductance to be measured by utilizing the second data set based on a preset multi-physical field coupling model for mapping the internal physical state to the electrical performance; the residual quantization analysis module is used for calculating residual errors between the first data set and the predicted electrical performance data set so as to quantize deviation between actual electrical performance and predicted electrical performance of the inductor to be detected; the failure mechanism diagnosis module is used for identifying the current dominant failure mechanism of the inductor to be tested based on the characteristics of the residual error and generating a diagnosis indication signal for representing the dominant failure mechanism; The closed loop feedback optimizing module is used for responding to the diagnosis indication signal and executing self-adaptive adjustment operation, and the self-adaptive adjustment operation comprises the following steps: And adjusting the type of stress applied to the inductor to be tested, and updating a prediction model for predicting the residual service life of the inductor to be tested.

Description

Method and system for evaluating service life of inductor Technical Field The invention relates to the technical field of measuring electric variables, in particular to an inductor service life assessment method and system. Background The technology of evaluating the service life of an inductor is originated from the increasing demand for the reliability of electronic components, and in the early days, the inductor is often regarded as a high-reliability passive device, the evaluation is mainly focused on initial electrical performance parameters, and the service life problem is not fully emphasized. Along with the development of power electronics technology to high frequency, high power density and miniaturization, a thermal acceleration life test based on an Arrhenius model, finite element simulation analysis and a multi-physical field coupling model are established to research a degradation mechanism of a key material under multiple stresses of electricity, heat and force, so that reliable running time of an inductor under a specific working condition is accurately predicted, and a key scientific basis is provided for design and preventive maintenance of a high-reliability system. In the prior art, the publication number is CN120028605A, the name is a high-frequency inductance evaluation device and an inductance evaluation method, by setting a minimum test circuit for the high-frequency inductance to be tested, and evaluating the S parameter of the obtained minimum test circuit in a high frequency band through the vector network analyzer, the high-frequency inductance meeting the radio frequency link requirement can be obtained, the capability of rapidly screening and evaluating the high-frequency inductance is realized, the batch test of products on a production line is avoided in real work, the performance of the high-frequency inductance is indirectly judged through the performance index and the direct rate of the products, and the performance of the inductance under the high-frequency condition can be rapidly and accurately evaluated by the high-frequency inductance evaluation device to be tested, so that the flexibility and the applicability of the test are improved. However, the technical scheme has the following technical defects: The core of the inductor life assessment is to simulate the long-term degradation process of the inductor under severe working conditions such as high temperature, high current and the like, and the technical scheme is essentially a performance measurement system under a normal-temperature small-signal environment; Secondly, the above solution does not compensate for the measurement errors caused by the ageing of the test fixture itself, which is closely related to the previous drawbacks. Since the evaluation is based on the S-parameter of the whole "minimum test circuit" containing the inductance, performance degradation of the test circuit board, connectors and other components themselves can occur once it is subjected to burn-in testing in a high temperature, iso-stressed environment. Therefore, the finally measured S parameter change is the result of the combined action of the inductance degradation and the test fixture degradation, errors of the inductance degradation and the test fixture degradation cannot be separated, the actual performance attenuation of the inductance cannot be accurately quantified, and the scientificity and the credibility of the evaluation result are lost. Disclosure of Invention The invention aims to provide a method and a system for evaluating service life of an inductor, which are used for solving the problems in the background technology. In order to achieve the above purpose, the present invention provides the following technical solutions: The service life evaluation method of the inductor comprises the following specific steps: synchronously acquiring the inductor to be tested under the stress environment while applying preset electric excitation: A first data set for representing the actual electrical performance of the inductor to be tested and a second data set for representing the internal physical state of the inductor to be tested; generating a predicted electrical performance data set of the inductance to be measured by using the second data set based on a preset multi-physical field coupling model for mapping the internal physical state to the electrical performance; calculating residual errors between the first data set and the predicted electrical performance data set to quantify deviation between actual electrical performance and predicted electrical performance of the inductor to be tested; Identifying the current dominant failure mechanism of the inductor to be tested based on the characteristics of the residual error, and generating a diagnosis indication signal representing the dominant failure mechanism; and step five, responding to the diagnosis indication signal, and executing self-adaptive adjustment operation, wher