Some faults caused by lightning strike on the HV circuit breakers in East China Grid are analyzed
and the results show that the faults depend on not only the structure of circuit breakers
but also the insulation coordination of substation
which exerts more influence on the faults than the former.A method is hence proposed to prevent the fault by setting a surge arrester at inlet(or outlet) side of circuit breaker
or setting a surge arrester with gap at line terminal tower if there isn’t a position for setting the arrester within substation.