500 kV GIS substation becomes operational in Hunan, China June 23, 2022 | Asia-Pacific News The State Grid Hunan Electric Power Company, a part of State Grid Corporation of China (SGCC), has put a 500 kV gas-insulated switchgear (GIS) substation into operation in Hunan. This content is available to only paying subscribers. Username or E-mail Password Remember Me Forgot Password