This paper combines incoming lines with a 500 kV GIS substation to investigate the lightning over-voltage of 500 kV GIS substation via ATP-EMTP simulation program with respect to the influences of impulse voltage-second characteristics of insulator strings

impulse corona of incoming lines

impulse grounding resistance of tower

and position of lightning.The result shows that impulse corona and grounding resistance of the tower which is close to the substation exert great influence on over-voltage

maybe the lightning over-voltage is not the maximum when lightning strike the tower which is close to the terminal door-typed structure

and a group of arresters installed on bus can decrease the over-voltage effectively when the over-voltage of the equipment is very serious.This research takes both safety and economy into account to provide a reference for the lightning over-voltage protection of GIS substations.