Study on a protection scheme for a 500kV GIS substation against direct lightning strokes

The preliminary designed protection scheme for a 500 kV GIS substation against direct lightning strokes was adopting combined protection by installing two parallel shield wires and two lightning masts. To confirm the feasibility of the proposed scheme, polygon method and rolling sphere method were used. Results obtained by these two methods showed that the combined protection scheme for the 500 kV substation against direct lightning strokes was feasible.