抄録
Over the past 20 years there have been several studies examining the impacts of geomagnetic storms on high voltage power systems on the Earth's surface. These were strongly motivated by the blackout of the power grid in Quebec, Canada in March 1989 due to a severe geomagnetic storm created by a coronal mass ejection on the sun several days earlier. This paper evaluates examples of three major types of geomagnetic disturbances that typically occur (auroral electrojets, sudden storm commencements, and high speed streams due to coronal holes on the Sun). In each case the nature of the geomagnetic time variation is discussed along with its typical conversion to electric fields in the Earth. This allows a determination of the potential impact on a power grid. It is important to understand the relative importance of these different types of disturbances, as they have different latitudes of exposure, which are important for the locations of different power grids throughout the world.