A fast making vacuum circuit breaker research and its applications

The key to perform synthetic making test at full rated voltage for high voltage switches is the making device of current source, which should have the capability to withstand the static and transient voltage and can conduct short-circuit current without excessive erosion, moreover it ought to be hair-trigger and control accurately. A new kind of fast making switch is presented in this research, which based on parallel-connected triggered vacuum switch (TVS) and fast vacuum circuit breaker (FVCB) to form the basic optic-controlled unit, several basic units arrange in series can be increase the hold-off voltages. The chief aim of this research is to investigate the feature of FVCB to determine experimentally whether the provided FVCB was suitable for high voltage circuit breakers synthetic making test. In order to research and optimize the actuator of FVCB, lots of simulation and experiment have been carried out. As a result, the closing time of FVCB is less than 8 ms. The closing command of TVS and FVCB are sent synchronously, TVS acts in several microsecond and carries the high making current first. FVCB plays as the parallel protecting device. Once FVCB closed completely the making current will shift to this branch.