A first (and perhaps only – as this took longer than initially planned) walk through some of the interesting points of what happened yesterday (Sat 16th Nov 2019) when South Australia islanded from the rest of the NEM with the trip of the Heywood interconnector.
The multi-region islanding event on Saturday 25th August was a very rare event – perhaps the only one’s that occurred in the history of the NEM. It has generated plenty of questions – and driven our analysis further. We share some more observations here, and keenly await the draft AEMO report.
Following on from Saturday’s islanding event, we use our current interest in AEMO’s 4-second SCADA data to prove a little more…
Both the QNI and the Heywood interconnectors tripped around the same time on Saturday 25th August 2018 (not apparent at this time which one was first, and why), leading to both QLD and SA regions being separately islanded from the rest of the mainland NEM. This also contributed to over 1,000MW of load shedding in NSW and VIC, and presumably some frequency excursions in QLD and SA.