Insulation design of 25.8kV class gas insulated switchgear in Dry Air

Research on Eco-friendly gas used in gas insulated switchgear (GIS) has been studied in earnest since the Paris Climate Change Accord in 2015. Existing SF6 gas has excellent dielectric strength, but has a high global warming potential (GWP). On the other hand, dry air is easy to use in low voltage GIS because it has a lower global warming potential and low dielectric strength than SF6 gas.In this paper, the results of insulation test and electric field analysis of 25.8kV class gas insulated switchgear in Dry Air. The test was conducted with the test method of IEC 62271-1 "Dielectric tests". As a result of lightning impulse tests, insulation breakdown occurred in various shapes. Ansys Maxwell 3D electric field analysis was performed based on the test results.