Look how quickly the National Grid System managed to get the frequency back on track after a very challenging event last Friday.
One of our long term test loggers captured last weeks frequency event, which led to the loss of supply to nearly one million customers across the UK.
The first collapse is due to the loss of the 740 MWe Little Barford Power Station. The speed at which the frequency fell is probably indicative of a low inertia.
After 45 seconds the frequency has started to recover but then falls again possibly due to G59 [Prevention of Islanding] protection as other independent generation trips (Hornsea Offshore Wind Farm).
One minute and 15 seconds after the start of the event, at a frequency of 48.8 Hz, Low Frequency Tripping protection causes load to be disconnected and the grid starts recovering.