Impacts of geomagnetic storms on EHV and UHV power grids

This paper describes the threat of geomagnetic storms created by solar activity to EHV and UHV power grids based on the experience of the past. It is clear from the available data that the higher the voltage of the AC power system, the more vulnerable that system is to a particular geomagnetic storm. Given a description of the time and spatial variation of the geomagnetic field (past, present or hypothetical), it is possible to model the response of any specific high-voltage grid with a high level of accuracy. Models have been developed and validated in the past, and samples of that work are presented here. Through careful modeling, it is possible to design protection for highvoltage grids against this unique threat.