Research On XLPE Life Assessment Method And Test Equipment Considering Electrical Stress

People’s demand for electricity has been increasing in recent year with their rising living standards.Cable,as the main tool for electrical energy delivery,has been applied in more and more occasions.Most insulated cable are made from XLPE.XLPE cable is likely to be affected by electrical stress and mechanical stress during usage period,which may result in aging of insulation.This somehow will have an impact on the normal use as well as service life of XLPE.Therefore,it is meaningful to conduct a study on the aging and service life of XLPE.XLPE cable will be affected by many factors during its usage period.Those factors will result in aging of insulation and,even worse,damage of the cable.Thus,it is significant to figure out the factors of XLPE’s aging of insultation and service life.This research firstly had an introduction to XLPE’s aging of insulation.Then the stress factors such as electrical stress,thermal stress,and mechanical stress that affect the aging life of XLPE insulation materials are analyzed.Life index should be accessed in advance in order to analyze the service life of XLPE in the effect of Electrical stress.As a result,electric life model,Weibull distribution model and life index has been analyzed in this study.More attention was paid to law of inverse power law and the E-t Curve of XLPE material.Based on Weibull distribution function,Weibull distribution under accelerated life experiment has been analyzed,which contributed to the relation among Weibull shape parameters,scale parameter and life index under different variables.Then it analyzes the research background and engineering application value of the life index,and conducts a theoretical analysis and evaluation method research.Finally,it makes a study on how to obtain the life of the XLPE material through the life index.Finally this research analyzed the feasibility of an experimental device which is designed to test constant stress accelerated life.Test sample and test voltage were selected during short-time breakdown test,then the experimental device is used to acquire different statistics of breakdown from multigroup XLPE sample.Those statistics were assessed by constant voltage method and Weibull distribution in order to acquire life index,so that the service life of XLPE material can be calculated under any intensity.