Automatic Under Frequency Load Shedding (AUFLS)

Both QLD and SA islanded from the rest of the NEM on Saturday 25th August 2018

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.

Power System Frequency – What is it doing? – Why does it matter?

The East Coast power system of Australia has the worst frequency regulation in the developed world. This puts the system at risk whenever an event occurs which requires the generators to respond quickly – they can’t respond quickly if they have to wait for the system frequency to go outside its control system dead band.