Experimental Study On DC Surface Flashover Of Insulation Material Under Different Electric Fields

Surface flashover is a phenomenon that occurs on the interface between insulating material and insulating medium and runs through the poles.At present,materials commonly used in high voltage insulation are mainly silicone rubber and epoxy resin.In the practical operation of high voltage equipment,due to different electric field conditions,the phenomenon and mechanism of surface flashover are different.And the influence of surface flashover on the surface physical and chemical properties of the insulating material is not the same.In different electric fields,by comparing the surface flashover voltage and the influence of flashover on surface property of material,it is helpful to identify the electrical characteristics of the surface discharge of different electric fields and the damage caused by flashover.This study has great significance to the modification of insulating material and improvement of insulation performance of equipment.Based on the project of Natural Science Foundation of Hebei Province ‘Study on materials surface properties of epoxy resin pre and post surface flashover by DC in SF6/N2 under high pressure,' the experimental research on the DC surface flashover of insulation material under different electric fields is carried out,specific work is as follows:(1)Designing three different shapes electrodes,through the collocation of the electrodes to simulate different kinds of electric fields,and Ansoft software is used to simulate the electric fields of different types.This paper describes the experimental platform of DC surface flashover of insulation material,and the installation and adjustment of the electrode on the platform.In this paper,the flashover experiment is carried out with the help of the platform,and the arc characteristic of DC surface flashover under different electric field is observed with the aid of the platform.(2)The DC surface flashover experiments of silicone rubber and epoxy resin under different fields will be carried out.By changing the electrode shape,discharge distance,pressure and other parameters to observe the electrical characteristics of surface flashover.and compare the surface flashover voltage under different electric fields.The statistical method of Weibull distribution is proposed.the flashover voltage of the discharge parameters is analyzed by using the statistical method based on Weibull distribution,then distinguish the ability to resist flashover voltage.under an electric field.(3)Using scanning electron microscopy(SEM),atomic force microscopy(AFM)and Fourier transform infrared spectroscopy(FTIR)to observe the morphology and chemical properties of silicone rubber and epoxy resin before and after discharge,and then the influence of surface flashover on the surface physical properties of two kinds of insulating materials are analyzed.