High-voltage power grid disturbances during geomagnetic storms

The very strong geomagnetic storm on 13 March 1989 caused extensive disruptions of high-voltage power circuits especially in the Province of Quebec, Canada, but also to a lesser degree in Scandinavia. Similar events have occurred earlier, among others, during the great storms of 13 - 14 July 1982 and 8 - 9 February 1986. Some of the high-voltage power grid disturbances are related to the shock-like disturbances accompanying the compression of the front of the magnetosphere by sudden enhancements in the solar wind plasma flow. Other cases are related to extraordinarily intense substorm events. The relations between magnetic disturbances and high-voltage power grid disturbances during these storms are presented and possible precautions against adverse effects are discussed.