Evaluation of Current Switching Performance with Synthetic-Air Disconnector and Earthing Switch

Gas-insulated switchgear (GIS) employing sulfur hexafluoride (SF₆) gas has contributed significantly to the design of compact substations and high operational reliability in Japan, owing to its excellent dielectric and current interruption characteristics. However, because SF₆ gas has an extremely high global warming potential (GWP), emission regulations have been progressively tightened, particularly in Europe and the United States. As a result, the transition to SF₆-free technologies is accelerating in Japan as well, supported by the roadmap issued by the Japan Electrical Manufacturers' Association (JEMA) and collaborative activities involving electric utilities and manufacturers. Discussions regarding the early deployment of SF₆alternative technologies are also intensifying in…