Prediction Method Of Electrical Life Analysis For AC Contactor

AC contactor is one kind of controlling low-voltage electric appliances which is widely used,mainly used for frequently making and breaking AC main circuit and large capacity controlling circuits in a long distance.Its scope of application is also related to all aspects of national economy,for example,agriculture,industry,and people's living.Therefore,accurate prediction of reliability and residual electrical life of AC contactor is of great importance in improving reliability and safety of electrical controlling system.In this paper,the CJX2-32 type AC contactor is chosen to be the object,and the residual electrical life prediction of AC contactor has been studied.Firstly,this paper studies the method of Wiener process,arc erosion is taken as a decisive factor to describe degradation of electrical performance.The degradation data of normal distribution is constructed by segmenting accumulation of arc erosion.The performance degradation model of AC contactor is established based on the Wiener process.Secondly,the electrical life for AC contactor is the minimum time when the degradation data beyond warning threshold in the process of the performance degradation,thereby the probability density function and reliability function of residual electrical life for AC contactor is obtained,and point estimation value and interval estimation value of residual electrical life for AC contactor are obtained.Thirdly,AC contactor electrical life simulation test is conducted using Monte-Carlo method,the performance degradation model of AC contactor is established based on the simulation test data.The simulation test shows that the electrical performance degradation model is effective.Finally,AC contactor electrical life test is conducted and degradation data is obtained.The performance degradation model of AC contactor are established based on the Wiener process and BP neural network,and the process of residual electrical life prediction is demonstrated.The result shows that the prediction methods can be used to predict the residual electrical life of AC contactor,and the error is acceptable in practical application.