Surge arrester is a kind of overvoltage protector, which is mainly used to protect various electrical equipment (transformers, switches, capacitors, wave arresters, transformers, generators, motors, power cables, etc.) in power systems, railway electrification systems, and communication systems. ) is protected from atmospheric overvoltage, operating overvoltage and power frequency transient overvoltage, etc., and is the basis for the insulation coordination of power systems