Welcome to the report of the PQopen measurement network for 2026-09.
News of PQopen Network
Thanks to Beckhoff Automation, measurement data from DK/Kolding is now available!
Summary
Evaluated is the 1s-mean value of the mains frequency measured in CH/Solothurn.
| Statistics | Value and occurrence |
|---|---|
| MIN | 49.8801 Hz (2026-09-05 09:30:55 CEST) |
| 1% Percentile | 49.9433 Hz |
| MEAN | 50.0004 Hz |
| 99% Percentile | 50.0539 Hz |
| MAX | 50.1477 Hz (2026-09-26 17:01:00 CEST) |
Daily Mean

Rate of Change of Frequency (ROCOF)

Frequency Spread

Other Abnormalities
Deviations of frequency below and above the ±100 mHz band, with the change to the previous month in brackets:
| < 49.9 Hz | > 50.1 Hz | |
|---|---|---|
| Count of threshold crossings | 24 (+14) | 24 (-4) |
| Number of seconds below/above | 221 (+90) | 449 (-35) |
Events
List of all detected events
| Timestamp (UTC) | Timestamp (CET) | Text | Category |
|---|---|---|---|
| 2026-09-29 05:21:27 | 2026-09-29 07:21:27 | Turkey | Generation Outage |
| 2026-09-25 14:51:07 | 2026-09-25 16:51:07 | FR: PALUEL 1 (1330 MW) | Generation Outage |
| 2026-09-23 19:25:40 | 2026-09-23 21:25:40 | Eastern Germany | Generation Outage |
| 2026-09-19 16:16:34 | 2026-09-19 18:16:34 | DE/DK Oscillation Peak | Oscillation |
| 2026-09-18 02:07:43 | 2026-09-18 04:07:43 | Spain | Generation Outage |
| 2026-09-16 07:47:13 | 2026-09-16 09:47:13 | Unknown Loss of load / loss of Transmission | Loss of load |
| 2026-09-15 13:20:12 | 2026-09-15 15:20:12 | NORDIC: Unkown Outage of about 1000MW | Generation Outage |
| 2026-09-13 01:14:52 | 2026-09-13 03:14:52 | DE/Essen Area | Generation Outage |
| 2026-09-08 08:46:54 | 2026-09-08 10:46:54 | NL/Middelburg: untypical voltage swell, possible tap changer controller failure | Voltage Swell |
| 2026-09-05 18:36:55 | 2026-09-05 20:36:55 | DK: Second Oscillation Peak | Oscillation |
| 2026-09-05 16:32:42 | 2026-09-05 18:32:42 | DK: Oscillation Peak | Oscillation |
| 2026-09-05 04:27:20 | 2026-09-05 06:27:20 | DK & Northern Germany | Frequency Swing |
| 2026-09-04 23:59:21 | 2026-09-05 01:59:21 | Northern Germany 2x | Voltage Dip |
| 2026-09-04 13:44:43 | 2026-09-04 15:44:43 | Spain | Voltage Dip |
| 2026-09-03 07:42:49 | 2026-09-03 09:42:49 | NL: Maasvlakte 3 (1070 MW) | Generation Outage |
| 2026-09-01 17:59:10 | 2026-09-01 19:59:10 | German grid near Cologne was attacked: power outages of several generations: https://www.krone.at/4278964 | Generation Outage |
| 2026-09-01 05:31:25 | 2026-09-01 07:31:25 | Unknown Event in DE/Berlin area | Frequency Swing |
Event Metrics
Automatically derived from the event plots: frequency nadir/zenith (10-cycle moving average), peak ROCOF (500 ms window per ENTSO-E convention), settling time (time until every location stays within ±10 mHz of 50 Hz) and the location with the highest peak ROCOF.
| Timestamp (UTC) | Event | Min in Hz | Max in Hz | Peak ROCOF in mHz/s | Settling in s | Peak location |
|---|---|---|---|---|---|---|
| 2026-09-29 05:21:27 | Turkey | 49.9640 | 50.0123 | 84.5 | 7.9 | AT/Graz |
| 2026-09-25 14:51:07 | FR: PALUEL 1 (1330 MW) | 49.9687 | 50.0475 | 136.9 | 7.9 | ES/Pamplona |
| 2026-09-23 19:25:40 | Eastern Germany | 49.9730 | 50.0151 | 121.2 | 7.9 | ES/Pamplona |
| 2026-09-19 16:16:34 | DE/DK Oscillation Peak | 50.0004 | 50.0486 | 181.6 | 7.9 | DE/Stade |
| 2026-09-18 02:07:43 | Spain | 49.9609 | 49.9918 | 82.8 | 7.9 | DE/Berlin |
| 2026-09-16 07:47:13 | Unknown Loss of load / loss of Transmission | 49.9733 | 50.0447 | 93.2 | 7.9 | NL/Eindhoven |
| 2026-09-15 13:20:12 | NORDIC: Unkown Outage of about 1000MW | 49.9158 | 49.9982 | 63.6 | 7.9 | SE/Malmoe |
| 2026-09-13 01:14:52 | DE/Essen Area | 49.9578 | 50.0101 | 65.5 | 7.9 | CH/Solothurn |
| 2026-09-08 08:46:54 | NL/Middelburg: untypical voltage swell, possible tap changer controller failure | 49.9822 | 50.0024 | 43.8 | 4.9 | ES/Pamplona |
| 2026-09-05 18:36:55 | DK: Second Oscillation Peak | 50.0043 | 50.0416 | 137.4 | 7.9 | DK/Kolding |
| 2026-09-05 16:32:42 | DK: Oscillation Peak | 50.0169 | 50.0652 | 177.8 | 7.9 | DK/Kolding |
| 2026-09-05 04:27:20 | DK & Northern Germany | 49.9748 | 50.0733 | 218.0 | 3.6 | DK/Kolding |
| 2026-09-04 23:59:21 | Northern Germany 2x | 49.8496 | 50.0974 | 1012.5 | 7.9 | DE/Stade |
| 2026-09-04 13:44:43 | Spain | 49.9471 | 50.0032 | 354.6 | 7.9 | ES/Pamplona |
| 2026-09-03 07:42:49 | NL: Maasvlakte 3 (1070 MW) | 50.0076 | 50.0506 | 60.4 | 7.9 | NL/Eindhoven |
| 2026-09-01 17:59:10 | German grid near Cologne was attacked | 49.9177 | 50.0261 | 995.4 | 7.9 | DE/Essen |
| 2026-09-01 05:31:25 | Unknown Event in DE/Berlin area | 49.9369 | 50.0043 | 459.0 | 7.9 | DE/Berlin |
Below, there are several graphs, each representing a detailed time series plot of cycle-by-cycle frequency as well as 10-cycle moving average, phase angle difference and voltage magnitude.
Central Europe Area









2026-09-08 08:46:54 (UTC): NL/Middelburg: untypical voltage swell, possible tap changer controller failure







Nordic Area

Yours,
Michael
