A Novel High-Efficient and Miniaturized Operating Method for Ultra-Fast Vacuum Switch

As one of the most important component in mechanical and hybrid dc breaker (MCB and HCB), operating time of ultrafast vacuum switch (VS) determines the breaking speed of MCB and HCB. However, limited by the high capacitive storage energy requirement of Thomason-coil actuator (TCA), the low-efficiency and large-volume of operating mechanism are main restrictions for wide application of ultrafast VS. This article proposes a high-efficient and miniaturized operating method for ultrafast VS by recycling the residual energy in capacitor banks for sequential open- and close-operations (O-C). Mathematical model of ultrafast VS during the sequential O-C operation process is established, and the prototype with rated parameters of 3.6 kV/2.5 kA/1ms is developed for experimental verification. The research shows that by using the proposed method, the total required capacitive storage capacity for sequential O-C operation is decreased by 50%, from 2038 to 1019 J, resulting in the doubled operating efficiency. In addition, the cost and volume of the operating mechanism for ultrafast VS are decreased significantly.