Effect of Metal Particle Position in Surface Charge Accumulation on DC GIS Insulator

This paper concentrates on the issue of surface charge accumulation on the basin-type insulator surface affected by metal particles in DC gas-insulated switchgear (GIS). The resting positions of the particles inevitably introduced on the insulator were determined. Down-sized insulators were selected as test samples, and after being charged by ±15 kV DC voltage for 1 hour, the charge distributions on both concave and convex surfaces were obtained. The obtained results suggested that the charge injection was strengthened by the particles attached to the electrodes and the surface charge spot was induced by the metal particle attached to the center conductor.