Study On The Factors Affecting The Surface Insulation Characteristics Of Basin Insulators

Basin insulators are important insulation components of GIS equipment,but frequent flashover accidents have become one of the main causes of insulation failure in GIS systems.At present,the trigger mechanism and factors for the flashover failure of the basin insulator are not clear,which limits the further improvement of the reliability of the GIS insulation system.Aiming at the flashover problem of basin insulators,based on the potting and molding process of basin insulators,three typical defect samples were prepared.Based on the simulation method of electrostatic field simulation,three typical defects were used to simulate epoxy for basin insulators.The effect of electric field distribution on the surface of composite samples was tested by ultrasonic method.The partial discharge initial voltage on the surface of the sample was tested by three kinds of typical defects.The effects of three typical defects on the power frequency insulation characteristics of the sample surface were studied.On this basis,the effect of alumina filler on the electric field distortion of the surface of the basin insulator was studied.The power frequency of the insulation containing different alumina fillers was studied experimentally.Flashover voltage and withstand voltage time.The results show that the curing shrinkage,surface bubbles and metal particles can significantly reduce the partial discharge starting voltage of the epoxy composite insulator and reduce its surface insulation ability;the alumina filler will cause the surface of the basin insulator to appear on the micrometer scale.The electric field is distorted.The larger the electric field distortion of the surface of the basin insulator on the micrometer scale,the lower the flashover voltage of the power plane with the spherical-like alumina-filled insulator is lower than the non-spherical shape.Alumina-filled insulation,the difference between the two is less than 5%,but the power-frequency withstand time of the spherical-like alumina-filled insulation is significantly lower than that of the non-spherical alumina-filled insulation.The research results hope to provide reference for structural optimization design and formulation optimization of basin insulators.