Calculation analysis of geomagnetically induced currents with different network topologies

The topology of the power system significantly affects the amplitudes of geomagnetically induced currents (GIC) and their flow in the network. In this paper, we collect the typical resistance values for the 220kV, 500kV, 750kV and 1000kV systems in China. Using these data we calculate the line GIC and substation GIC with different network topology models, also depict the characteristics of the GIC in these models. GIC grows with increasing line length but approaches an asymptotic constant value. However it is shown that a more relevant parameter than the individual line length is the length of the whole system. The results of these studies provide a guide to estimating GIC impacts precisely on future power systems.