Figure 2 shows an example of such a system modeled in PowerWorld Simulator with Bus 1 and its
generator (Bus 3) in Substation A, and Bus 2 with its generator (Bus 4) in Substation B. Assume Buses 1
and 2 are joined by a 765 kV line that has a per phase resistance of 3Ω, the per phase resistance of the
high side (grounded side) coil of each of the two transformers is 0.3Ω, and the grounding resistance for
each of the substations is 0.2 Ω. Let the magnitude of the GMD induced voltage in the 765 kV line be
150 volts, with a positive polarity on the Bus 1 side.with the flow from the grounding into the high side coil of the Substation B transformer, down the 765
kV line into the high voltage coil in Substation A and back into the ground. In the figure the direction
and size of the brown arrows superimposed on the transmission line and transformers are used to
visualize the direction and magnitude of the GIC flow
1
.