Study on geomagnetically induced currents in the Swiss transmission system

5-2-2013 — /europawire.eu/ — Powerful solar storms create geomagnetically induced currents (GIC), and the resulting electromagnetic interaction has the potential to interfere with grid operations. In the worst-case scenario, geomagnetic interactions can trigger large-scale power outages. One famous example is the March 1989 incident in North America when a power system failure was brought about in Hydro-Québec’s system. Around six million people were left without electricity for nine hours.

The Earth is an electro-conductive sphere that reacts to oscillations in the magnetic field, particularly in northern regions. It is therefore impossible to rule out similar interactions occurring in Continental Europe. This study was designed to calculate the potential impact of geomagnetically induced currents on the Swiss transmission grid.

GIC has minimal impact in Switzerland

It is essential to understand, assess and, where necessary, minimise the impact of GIC on power grids for improving overall system security. The study outlines the physical processes involved in GIC and their effects on the grid. It also explores potential countermeasures drawn from industrial experience.

The study concludes that the risk to Switzerland is very low. Quantitative simulations reveal a comparatively low level of induced voltages in Switzerland. There is no critical impact on zero-balanced reactive power and voltage level. Nevertheless, the study does identify several possible precautionary measures. These are currently under review in specialist units.

Swissgrid supports academic research into relevant energy issues

The study «Geomagnetically Induced Currents in the Swiss Transmission Network» was carried out by the Research Centre for Energy Networks at ETH Zurich (ETH-FEN) on behalf of Swissgrid and the Swiss Federal Office of Energy. The research centre was supported by a specialist in cosmic radiation, Professor Flückiger from the University of Bern.

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