Lightning transient characteristics of a 500-kV substation grounding grid

Lightning transient characteristics of the grounding grid is the fundamental performance for lightning protection of the substation. The stability and safety of the 500-kV substation is of great importance to the safe operation of the power system. The characteristic of grounding grid is quite different from that at the power-frequency condition when subject to lightning impulse current. Using CDEGS software, a 500-kV substation grounding grid and its framework model are developed for the transient analysis of ground potential rise (GPR), touch voltage and the step voltage when lightning rods are struck by lightning impulse current. According to IEEE standard 80-2000, this paper puts forward some improvement opinions about the grounding grid of the 500-kV substation.