At the break of 24 July the UCTE grids frequency dips to 49,82 Hz
At the transition from 23 to 24 July 2020, a massive frequency dip occurred. Similar to the event of 10 January 2019, a frequency value of 49.82 Hertz was recorded at all Gridradar stations across Europe.At a frequency of 49.80 Hertz, transmission system operators start load shedding to counteract a blackout. Interestingly, however, this time the entire system seems to be running down in equal measure. None of the Gridradar stations recorded significant outliers.
Different reactions of the phase angle
On the other hand, there are smaller differences when looking at the phase angle differences. The phase angle difference between two measuring stations over time allows conclusions to be drawn about the change in power flows between the measuring stations. This shows, for example, that there was a slightly increased power flow from Austria to Germany. Especially locations of larger generation plants (except near Brauweiler) also show larger jumps in the phase angle around the time of the lowest frequency value. This indicates an active countermeasure.
However, the aFRR call-off values available on 24 July, both in Germany and in the entire continental European interconnected system, do not show any exceptionally large changes compared to other days, especially not in the quarter hour from 00:00. However, a high mFRR retrieval takes place in the following quarter hour from 00:15 in Germany - at a time when the enormous drop in frequency could probably already be recovered by trading activities.
This event is one of a large number of or almost daily frequency deviations from the target frequency above 100 mHz that have been observed since March. As soon as more detailed information on the current event is available, we will add it here.