Research of Influencing Factors in the Simulation on 500kV GIS Substation

There are some special characteristics on over-voltage protection due to GIS substation itself. And for 500kV ultra high voltage network, some problems such as lightning over-voltage protection and the arrangement of arresters are needed to be solved. Taking a 500kV GIS pumped-storage power station as sample, this paper uses graphic electromagnetic transient calculation program ATPDraw, synthesizes the substation and incoming lines, build proper models for simulation, and considers various factors, such as lightning location, bus bar working mode, arresters' type and collocation, cables' length, entry capacitance and grounding resistance of towers, to analyze the influence of lightning incoming surge on GIS substation generally. The maximum amplitude of over-voltage happens when back flashover is in near zone. The larger operation network is, the lower over-voltage level on main transformer is. Arresters works well and it is important to allocate the arresters on the entry of overhead lines. In project design, arresters should be allocated near the front part of cables. Entry capacitance of main transformer has little effect to the whole over-voltage level. The simulation results could provide some reference information for the design of ultra high voltage GIS substation.