Space Weather Impact on the Scandinavian Interconnected Power Transmission System

Abstract

Geomagnetic storms (GMS) can seriously affect high voltage power transmission grids. More specifically, GMS can inject geomagnetically induced currents (GICs) into the power network, thus causing instabilities and eventually leading to grid collapse. Since GMS are expected to cause more pronounced disturbances at high latitudes, this report addresses the effects of GMS on the Scandinavian interconnected power transmission grid, including Finland, Sweden and Norway. By applying 100-year-benchmark scenarios, we analyzed potential space-weather triggered voltage instabilities in the power grid considering mono-phase transformers, which are known to be more vulnerable to GIC injection, and three phase transformers, which are less vulnerable. Our simulations indicate that the three-phase configuration of the network is significantly more robust than the mono-phase one. For a system with only three-phase transformers, the likelihood of grid collapse is very low, and collapse only occurs for the worst-case scenario with extremely high geoelectric field intensities. Our results indicate that lines that experience higher reactive power losses during normal operation are more likely to increase losses during a GMS event. According to our study, the portion of the Scandinavian interconnected power transmission grid most vulnerable to extreme space weather is the part where the highest reactive losses in transmission lines and in voltage magnitudes are observed. This corresponds to the southern parts of Sweden and Norway. In the near future, this study will be extended to assess the risk of extreme space weather for larger portions of the EU power grid. Space weather impact on the Scandinavian interconnected power transmission system Roberta Piccinelli and Elisabeth Krausmann