Modelling of Geomagnetically Induced Currents in the Czech Transmission Grid

TL;DR

This study models the maximum geomagnetically induced currents in the Czech power grid during geomagnetic storms using the Lehtinen-Pirjola method, providing estimates of GIC magnitudes under different storm conditions.

Contribution

It applies a detailed GIC modeling approach to the Czech transmission network, offering new insights into potential GIC levels during geomagnetic storms.

Findings

Maximum GICs during Halloween storm-like events are about 15 A.

Extreme storm conditions could produce GICs up to 40 A.

Statistical correlation suggests repeated low-level GIC exposure may impact grid devices.

Abstract

We investigate the maximum expected magnitudes of the geomagnetically induced currents (GICs) in the Czech transmission power network. We compute a model utilising the Lehtinen-Pirjola method, considering the plane-wave model of the geoelectric field, and using the transmission network parameters kindly provided by the operator. We find that the maximum amplitudes expected in the nodes of the Czech transmission grid during the Halloween storm-like event are about 15 A. For the "extreme-storm" conditions with a 1-V/km geoelectric field, the expected maxima do not exceed 40 A. We speculate that the recently proven statistical correlation between the increased geomagnetic activity and anomaly rate in the power grid may be due to the repeated exposure of the devices to the low-amplitude GICs.