Geomagnetically induced current sensitivity to multiple substation grounding resistances

The impact of geomagnetic disturbances (GMDs) on the high voltage electric grid can result in severe damage by producing geomagnetically induced currents (GICs). Protection against GMD therefore necessitates the accurate estimation of the GICs. GIC estimation can be challenging since they depend in part upon the substation grounding resistances, which are not always well known. To address this issue the paper proposes an algorithm to calculate the sensitivity of the GICs at any substation to these resistances. The method is demonstrated on several power grid models.