Development of an interrupting chamber for 1000 kV high-speed grounding switches

High-speed grounding switches (HSGS) for 1000 kV (UHV) transmission lines are required to interrupt a delayed zero current with a long arcing time. This requirement was met by allowing pressure rise in the opening operation to last efficiently for a long time through optimizing the exhaust volume and the residual volume of a puffer-type interrupting chamber and utilizing the effect of pressure rises due to arcing.