It can be predicated that the study results are useful to the design of overvoltage protective device in electric power system and the development of canceling arc light earthed overvoltage device and small electric current chosen equipment 本文的研究结果对电力系统过电压保护装置的设计及消除弧光接地过电压和小电流选线装置的开发具有实际指导意义。