Particle Initiated Breakdown Inside Gas Insulated Switchgear

SF6 has been widely used as insulation media for gas insulated switchgear (GIS) and gas insulated transmission line (GIL), due to its excellent insulation and arc quenching properties. Although the SF6 gas has superior dielectric properties, SF6 gas made an issue of environmental influence due to its high global warming potential (GWP=23900). Thus the development of an alternative gas or gas mixtures having much lower GWP is strongly required. So in this book, mixtures composed of a strongly electronegative gas of high dielectric strength such as SF6 and an ordinary gas (N2, CO2 or air) are used. The presence of contaminating particles lowered the dielectric strength of the gas mixtures sharply. This work considered various positions and types of particle contamination in the gas mixture which is very limited in the published researches. The determination of the breakdown voltage in the gas requires the knowledge of the potential and field distribution on and around the charged particle surface. So in this book, the electric potential and field distribution are studied with a various shapes of contaminating particles for its favorable accuracy, when applied to high voltage problems