| Residual current operated circuit breaker are high-reliability and long-life protection appliances that protect the life and property of power users in low-voltage power distribution systems.The traditional life test cycle is long and the test cost is high.It is not possible to obtain sufficient failure data in a short period to conduct a reliability analysis of the Residual current operated circuit breaker.If high stress can be applied to the Residual current operated circuit breaker and its performance degradation process is accelerated,the test will be greatly shortened.Only using accelerated degradation data to build a degradation model can complete the reliability prediction of Residual current operated circuit breakers.Therefore,it is of great significance to study the performance degradation test of earth Residual current operated circuit breakers and analyze the performance degradation law between different stresses.In this paper,an electronic Residual current operated circuit breaker is taken as the research object.(1)Designed a constant accelerated degradation test with temperature as the accelerated stress,determined the test parameters such as the characteristic degradation amount,failure threshold,and test period.The Arrhenius model was used as the acceleration model to conduct the accelerated degradation test on the Residual current operated circuit breaker to obtain the remaining actions Data of accelerated degradation of current;(2)Based on the accelerated performance degradation data,the performance degradation trajectory of the Residual current operated circuit breaker is established,and the overall residual operating current of each accelerated stress Residual current operated circuit breaker shows a downward trend,and the degradation increment of the residual operating current in each cycle is random Sex(3)Accumulate the degradation of the residual operating current in each cycle,and perform a normal distribution test on the segmented degradation to verify that it conforms to the Wiener process.A performance degradation model based on the Wiener process is established to use the residual action of the Residual current operated circuit breaker.When the current degradation reaches the failure threshold for the first time as a failure criterion,according to the time distribution of the first-time linear Wiener process reaching the failure threshold for the inverse Gaussian distribution,the probability density function and reliability function of the remaining life are derived,and then the maximum likelihood estimation method is used The parameters are estimated,and the residual life prediction model of the Residual current operated circuit breaker is established to predict the residual life of the Residual current operated circuit breaker under each accelerated stress;(4)The gray model is used as a supplement and proof of the Wiener process prediction.The accuracy of the gray model is verified by the residual test,the correlation test,and the posterior difference test,and the pseudo-failure life of the Residual current operated circuit breaker is predicted.The process is combined with each other to make a comprehensive prediction to obtain the pseudo-failure life under each acceleration stress.Through the Arrhenius acceleration model,the least square method is used to estimate the life of the Residual current operated circuit breaker under normal conditions. |
