Compressed gas insulated sub-stations (GIS) consist basically a conductor supported on insulators inside an enclosure which is filled with Sulphur-hexafluoride gas (SF6). Gas insulated sub-stations are high voltage substations, compact in nature, requires less maintenance when compared to air-insulated sub-stations. The compactness of GIS is due to use of SF6 gas, which has higher dielectric strength. Electrical insulation performance of compressed gas insulated sub-station (GIS) is adversely affected by metallic particle contaminants. Free conducting metallic particles, depending upon their location, shape and size, may lead to serious deterioration of the dielectric strength of the GIS system and also one of the major factors which causing breakdown of the system and leading to unexpected break in power.
GIS, CIGRE, Electrode systme
