Few have probably failed to read about the solar storm that hit the earth late Friday night 10 April and continued over the weekend. For most people, it was an opportunity to see the northern lights far to the south and on a significant scale. We could from Swedish Television take part of the news that the Swedish power grid (Svenska Kraftnät) was preparing for the event. Operations Manager Pontus de Mare said that “we are reducing capacities in the national grid and transferring less electricity between electricity areas to create extra margin for possible disturbances”.
Fortunately, there were no serious effects on the grids, but the event itself was significant and clearly detectable in the measuring data, as reported to us by customers from both Sweden and our Nordic neighbours.
The solar wind induces direct current in the electricity grid, which produces saturation effects in inductive components. The saturation in turn causes distortion, which creates harmonics that are measurable. The image shows how the harmonic content of even harmonics, THDeven, increases sharply.
For those interested, you can also study more deeply and see which individual harmonics were most affected. Individual harmonics have upper limits, and the fact was that in several places in the network, the levels exceeded the established limits according to EN 50160. For example, the 4:th tone rose to above the maximum limit of 1%.
What did it look like at your location? Contact us and we will be happy to help you look into this.
