Influence of Metallic Particle Contamination on Flashover Characteristics of Supporting Insulators in SF6

The supporting insulator is one of the most important parts in SF6 gas insulated switchgear (GIS). Flashover of supporting insulators would cause serious harm to the electrical system. Nowadays, with the rapid development of GIS, flashover characteristics of supporting insulators in GIS have attracted wide attention of lots of researchers. According to the previous research, it is found that metallic particles on the surface of supporting insulators have significant effect on flashover characteristics. However, the influence is not studied clearly, and agreements on the mechanism of flashover have not been reached, neither. This paper clarifies the influence of the position of defect and gas pressure on flashover characteristics. Possible explanations for those phenomena are given. A…