Effects of Geophysical Parameters on GIC Illustrated by Benchmark Network Modeling

Geomagnetically induced currents (GICs) are identified as a potential hazard to power grids. Significant progress in understanding the physical processes leading to GIC production and its effects on power grid components have been made in recent years. With the development of a GIC benchmark network, researchers are now equipped with a test model that can be used to separate the effects of different environmental conditions from effects of network configuration on the distribution of GIC in a system. This paper describes the effects of the environmental conditions (i.e., geomagnetic variations and earth conductivity structures) on GIC in the benchmark network. Geomagnetic variations during the October 29-31, 2003, space weather events are used, together with two realistic models of the earth conductivity (i.e., more resistive and more conductive). The results of the modeling of different geophysical scenarios expressed in terms of GIC distributions through the system and as two GIC-related indices show the crucial importance of the geophysical conditions in assessing the GIC risk to power systems.