Study On Development Characteristics Of Typical Defects Partical Discharge Of Epr Cable Terminals At Low Temperature

With the development of traction power supply and power transmission technology,electric traction locomotives in northwest China have gradually replaced internal-combustion locomotives,and ethylene-propylene rubber cable as an important component of electric locomotives has also been widely used.Ethylene-propylene rubber cable is an important way to supply power for on-board high voltage equipment.As an important component of electric locomotive,ethylene-propylene rubber cable is an important guarantee for the normal operation of electric locomotive.In order to avoid and effectively prevent the cable terminal defects in the low temperature environment,ensure the safe operation of electric locomotive in the low temperature environment,and improve the insulation characteristics of ethylene-propylene rubber cable terminal,this paper carried out research on the partial discharge development characteristics of ethylene-propylene rubber cable terminal with typical defects in the low temperature environment.This paper set up a typical defects under low temperature environment ethylene-propylene rubber cable terminal partial discharge test system.First of all,the platform of the test analyses the interference of environment and take effective ways to prevent effectively reduce background interference.Second,correction was carried out on the test platform of partial discharge,again,on the basic structure of ethylene propylene rubber cable terminal anatomy.Finally,the test system shown on the two-dimensional spectra and extract the partial discharge amount and the characteristics of partial discharge.The development process of partial discharge of three typical defects of ethylene-propylene rubber cable terminal spines,impurities and scratches at room temperature and low temperature was studied.First,will start typical defects of insulation degradation until the insulation breakdown process of S1,S2,S3 three stages,different stages of the spectra of partial discharge,average discharge,discharge times.Secondly,to extract the different defects under different environmental conditions in each stage of the growth rate of the average discharge,partial discharge phase interval,and the average discharge positive and negative half cycle of skewness Sk,Ku steep degree and the positive and negative half cycle profile distribution of correlation coefficient cc statistical parameters.Finally,the analysis and comparison show that under normal temperature and low temperature environment,the discharge spectrum,average discharge amount,number of discharges and discharge interval of the different typical defects are all the same as the insulation begins to deteriorate until the insulation breakdown becomes larger;the data shows local The trend of the discharge statistical parameters is related to the type of defects and environmental factors.