Study on the Development of Surface Flashover Induced by the Motion of Micro-metal Particle on the Surface of AC GIS Spacers Under Operation Condition

Abstract

In recent years, GIS insulation faults occur frequently. In order to reduce GIS failures and ensure power grid safety, it is urgent to find out the causes of flashover of GIS spacers along surfaces. In previous studies, the cause of surface flashover of GIS spacers is mainly suspected to be metal particles on spacer surface. However, the discharge mechanism and discharge development process of the surface flashover induced by micro-metal particles under operating conditions were not found. Therefore, an experimental platform for observation of micro-metal particle motion and high-sensitivity pulse current partial discharge on GIS spacer surface was established. Taking 5mm micro-metal particles as the object, the phenomenon of surface flashover induced by micro-metal particles under operating conditions was found. And the development process of its partial discharge was observed. The flashover mechanism was studied with electric field simulation, mechanical analysis and experiment, and the cause of a micro-metal particle induced flashover on the surface of GIS spacer was revealed.