Analysis of long‐term GIC measurements in transformers in Austria

During geomagnetic storms, rapid changes in the Earth’s magnetic field induce an electric field in the ground, may drive currents in the power grid. These are called geomagnetically induced currents (GICs) and they can lead to power grid operation problems and even transformer damage. In this study we present learning’s from five years of GIC measurements in Austria, which have been carried out in seven different transformers in the grid. Some power grid transformers show larger susceptibility than other transformers to magnetic field variations accompanied by larger GICs. We also identify some of the sources of noise in the data such as a city subway system, and investigate two geomagnetic storms from September 2017 and May 2021 in more detail.

DOI: 10.1029/2021SW002912

Locations of transformer neutral point current measurements in Austria
Principle of geomagnetic induction