Design Of Electrical Life Test Device For Control And Protection Switch And Research On Life Prediction Method

As an indispensable part of low-voltage electronic control systems,control and protection switch(CPS)can not only distribute electric energy,but also protect the electrical distribution network and industrial equipment from adverse effects such as short-circuit,overload,and undervoltage,electrical life directly affects the safety and stability of the entire system.Therefore,the prediction of the electrical life of the CPS has important academic significance.In this paper,the electrical life prediction methods for CPS are studied.According to IEC standards,GB standards and electrical life test standards,an electrical life test platform for control and protection switch is built,and 30 switches are powered by the platform.In the life test,the voltage between the contacts and the current flowing through the contacts were collected.In order to eliminate the error interference and make the data more accurate and reliable,this paper uses wavelet transform to preprocess the test data.Through the MATLAB software programming,the contact resistance value is calculated and the first 1000 contact resistances are selected as the electrical life prediction parameters.In this paper,making a statistical analysis of the selected contact resistance values,and the histograms of probability density of contact resistance and histogram of cumulative probability distribution were drawn.Three typical probability distribution functions of ? distribution,Weibull distribution and normal distribution are selected.The Kolmogorov-Smirnov test(KS test)is applied to the distribution types of contact resistance.The results show that the distribution conforms to the Weibull distribution.Electrical life prediction method based on mean and variance of Weibull distribution.Univariate linear regression was used to establish the relationship between mean,variance and electrical life.The significance test showed that there was a significant linear relationship between the mean,variance and electrical life.Therefore,the model can be well applied to the prediction of the electrical life of the control and protection switch to improve the safety performance of the electronic control system.