The lightning over-voltages on circuit breaker(CB)
disconnecting switch(DS)
bus bar
bushings and transformers were calculated by software ATP-EMTP when lightning waves intrude into 220 kV Baoneng Gas Insulated Substation.The lightning over-voltages of different running modes and lightning strike points were compared
and the effect of MOA on over voltages was analyzed.The result shows that the lightning over voltages are below the BIL of transformers and other equipments.The simpler the connection is
the more serious the over voltages of this mode are.The existing MOA can provide reliable protection for all equipments.