Degradation Analysis And Reliability Study Of Power Supply System Under Irradiation Environment

Electronic products are the key bonds of automating and intelligentizing equipment.Power supply is the direct source of power for ensuring the operation of electronic products,once the degradation fails,it will cause the whole machine to collapse and cause huge economic losses.At present,extensive research has been carried out on the analysis of degradation failure modes of power supply at home and abroad,but degradation failure analysis and reliability assessment are scarce in some special environments,especially in nuclear radiation environments.Therefore,this paper focuses on the degradation analysis and reliability evaluation of multi-output power supply under the nuclear radiation environment,and is committed to construct a complete reliability evaluation system,including system hardware development,test plan design,test exploration and theoretical analysis.Based on the previous three sets of tests about the self-designed power system in the nuclear radiation environment,it was found that the active devices in the power supply are very sensitive to nuclear radiation stress,which is the main reason for the failure of active devices.However,due to the constraints of the test cycle and economic cost factors,the entire evaluation system will face some problems such as the power supply components to be uncompletely failed,the number of test objects,and the number of degraded data samples.In view of the above problems,the main research contents of this paper are as follows:(1)Design of nuclear radiation test scheme for power supplyThe design of the test plan is the basic work of the power supply test and reliability evaluation.Based on the limited test conditions and cost,this paper proposes a set of effective test scheme,which mainly includes two sub-solutions: system degradation test and system failure criterion test.This scheme will follow the principle from component to subsystem and subsystem to system,make full use of limited test objects,obtain more test data to provide an accurate assessment of reliability.(2)Power component degradation trend predictionVoltage changes are an important criterion for evaluating the degree of degradation of electronic components.Considering the power supply system components in diagnostic tests failed to completely degradation failure problem,through access to part of the irradiation dose of degradation data,using support vector regression method,to forecast the trend of degradation of gradual failure components in the system,analysis and any irradiation dose of output voltage value,effectively made up for the defects of insufficient degradation data in reliability assessment.(3)Power component degradation analysis and reliability assessmentFor the problem of small samples of degraded data,this paper intends to analyze and evaluate the power components by combining Simulink simulation and Bootstrap resampling.By comparing with the Bootstrap sampling method,the validity and robustness of the proposed method are highlighted.In the process of degradation analysis,for the component of sudden failure,this paper will obtain the degradation trajectory of the component through mathematical modeling,for the gradual failure component,the degradation trajectory of the component will be obtained by least squares method.In the reliability evaluation process,the Monte Carlo method is used to obtain the reliability of the component,and the probability density curve is obtained by the kernel density estimation method.(4)Power supply reliability assessmentThe reliability block diagram is used to evaluate the system reliability of the power supply,to obtain the anti-radiation ability of the power supply,to reveal the weak links in the power system design,and to propose the design optimization plan and recommendations for the power supply.