Self breakdown properties and optimum of insulator envelope for MV gas switches

Two insulator bracing type MV gas switches are developed. One switch's HV electrode is cantilever and the insulator envelope is integrated. The other's HV electrode is out of insulator envelope and the brace cylinder is sectioned. Through self breakdown experiments and electrostatic field simulations, the optimum design of insulator envelopes is discussed and the reason for puncturing on the envelope of cantilever switch is given. The self breakdown properties of switches are discussed as well.