One day after the publishing of the Grid Frequency Report of February, there were some interesting things going on on Sunday. Two different oscillation phenomenon were detected, one in the lower band (0.24 Hz) and one in the middle band (3.15 Hz).
0.24 Hz Oscillation
There was a detection of a low-frequency mode at 11:00 (CET) which had it’s highest amplitude between 11:15 and 11:30 (CET). Spain was the possible originator, the oscillation was detected at every measurement location.
When we compare the PSD of Frequency and Voltage, we see, that there is no strong correlation between them. The interresting question is, what happened with the voltage? It stopped oscillating at all in the typical 0.1 – 0.2 Hz area.
3.15 Hz Oscillation
A second dominant oscillation was seen in northern Germany. This specific oscillation was previously detected in autumn, but not seen since this in that intensity.
Due to its characteristics, it strongly correlates with PV-generation and lower load. But the power generation was very similar to the previous day, where the oscillation was not detected. It would be very interesting, what and where the origin of this oscillation is. It is maybe located in a neighbour country with high PV-generation (e.g. Netherlands).
