Latest Trend of Application of Dry Air Insulation

Abstract

Dry air is one of the most popular insulation medium as SF₆ substitutes, and gas insulated switchgears which applied dry air have been manufactured since 2000 in Japan. Since dry air has only one-third insulation strength compared with SF₆ gas, dry air insulated switchgears need some improved techniques to downsize the equipment. This paper introduces a recent advance of dry air insulation techniques and their application to switchgears.