Basic investigation of a high-speed vacuum circuit breaker and its vacuum arc characteristics

A high-speed vacuum circuit breaker that can interrupt a fault current quickly by superimposing a high-frequency inverse current on the fault current to force current to zero is investigated. A requirement on the vacuum arc characteristics and its interruption capabilities for the circuit breaker are also studied. The requirements of the high-speed vacuum circuit breaker are estimated by an analysis of the excess torque calculation of a gas turbine generator under various fault conditions. Basic experiments on the vacuum arc characteristics and its interruption capabilities are conducted to clarify whether such vacuum arc might be applied to the high-speed vacuum circuit breakers.