3D Time Domain Simulation of Geomagnetically Induced Currents in Swedish Power Transmission Lines

Solar activity significantly influences the Earth's magnetosphere and ionosphere, causing current systems and space weather effects. The interaction between rapidly changing magnetic field and the Earth’s conductivity induces an electric field at the surface producing Geomagnetically Induced Currents (GICs) within critical human infrastructure, posing a risk of damage to power lines.

GICs strongly depend on the ground conductivity. Sweden has large spatial variations and complexity in the underlying ground conductivity structure across the country. In order to better understand GICs and for the identification of the worst-case scenarios for Swedish power transmission lines, 3D simulations are essential.

We present results from our GIC simulations, computed using our own 3D FDTD framework employing a Swedish ground conductivity model in high resolution. Compared to previous simulations of the Swedish power grid, ours is High Performance (runs on parallel GPUs), more flexible, and we can simulate the GICs in the time domain, instead of only the frequency domain as has been done before in simplistic approaches. This enables us to study GICs caused by much more realistic ionospheric source currents.