Grid Frequency Measurements of the Nordic Power System during 2018.

The grid frequency is measured in Zealand, Denmark (DK-2), as a part of the Nordic power system (ENTSOE RG-N).

336.4 days are measured with the DEIF MTR-3

11.7 days are measured with the Schneider PM800

16,9 days are not measured.

The MTR-3 and PM800 both has an accuracy of 10 mHz

There is one collumn with the UNIX timestamp and one collumn with the frequency measurement.
The dataset has a samplerate of 1 s, and missing samples are replaced with NaN so there are 24*3600*365=31,536,000 rows in the set.