Surface Flashover of Spacers in Compressed Gas Insulated Systems

The spacer surface in a compressed gas insulated apparatus constitutes the weakest electrical location in the system. Discharges originating at the spacer-gas-electrode interface and the electric field distortion at the spacer surface may cause surface flashover. The presence of water vapor, conducting particles, and other contaminants may alter the flashover characteristics of the spacer. This paper reviews the various types of spacers used in gas-filled systems. The flashover performance of spacers under contaminated conditions is also evaluated. Further areas of work on the flashover of spacers are proposed in order to obtain a better understanding of the mechanism of flashover and towards the design of an efficient and reliable compressed gas insulated system.