Special problems in gas insulated substations (GIS) and their effects on indian power system

The increase in demand for electricity and the growing energy density in the metropolitan areas have made it necessary to extend the high voltage network right up to the consumer. Gas insulated substations provide a best solution to the above problem and have been functioning for more than 30 years around the world. SF6 gas used in GIS has excellent dielectric properties, current interruption properties and also high heat transfer capacity. Considering the increasing population and increasing power demand across the globe, a complete study of the various problems in the GIS systems has to be completed so as to ensure an un-interrupted electric power supply to the customers and increasing the GIS applications. This paper brings to light the various special problems involved in GIS like Particle infusion in GIS, Insulating spacers and their reliability, SF6 gas decomposition in GIS, VFTs. The paper also discusses the significance of these problems, analysis based upon a graphical approach and the effect of these problems on the Indian power system.