Research on Lightning Over-voltage Protection for 500kV GIS Substation

This paper combines incoming lines with 500kv GIS substation, considering the influence of the impulse voltage-second characteristics of insulator strings, the impulse corona of incoming lines, the impulse grounding resistance of tower and the position of lightning. ATP-EMTP simulation program is applied to analyze the lightning over-voltage of 500kv GIS substation. The result shows that impulse corona and the resistance of tower which is close to the substation have great influence on over-voltage, when lightning strike the tower which is close to terminal door-typed structure, the lightning over-voltage may be not the most serious, and when the over-voltage of the equipment is very serious, a group of arrester is installed which can decrease the over-voltage effectively. This research thinking takes safety and economy into account, which can provide new reference for the engineering.