Geomagnetically-induced currents and harmonics

The same currents, high in the upper atmosphere, that result in the northern lights, also results in the so-called geomagnetically-induced currents (GICs) through long power lines.

The same currents, high in the upper atmosphere, that result in the northern lights, also results in the so-called geomagnetically-induced currents (GICs)through long power lines. Those current can result in saturation of power transformers and, with severe events, even in transformer disconnection, transformer damage and large-scale power blackouts. One of the indirect effects of GICs are increased levels of harmonics in the transmission grid, where especially low-order even harmonics can be used as an indirect indicator for the presence of GICs. In this project, we will use long-term measurements to further study the relation between geomagnetic disturbances (an indicator for the currents in the upper atmosphere that cause northern lights and GICs) and increased levels of even harmonics in the Swedish transmission grid.

Funding: Rönnbäret Foundation

Participants: Sarah Rönnberg, Roger Alves de Oliveira