Early observations from examining the AEMO’s four-second SCADA data from Tuesday afternoon

As I haven’t seen anything posted elsewhere, here’s a view of some selected fields from AEMO’s four-second SCADA (causer pays) data set that sheds a bit more light on the sequence of events last Tuesday.

Dundonnell windfarm tripped off rapidly and this was presumably driven by the initial fault as the 500kV lines near Anakie were flattened. System frequency then rose a little, possibly due to some customer loads around Melbourne tripping off in response to the voltage dip (my own airconditioning for one).

Interestingly, the Loy Yang A units don’t seem to go offline immediately and instead appear to progressively run down over about a minute, with unit 2 charting a different course from its cousins (maybe a coincidence, but it’s a different turbine-generator make from the other three LYA units).

All the usual caveats about this SCADA data not necessarily being completely accurate, and we certainly have to await AEMO’s reporting based on much fuller data to understand the underlying reasons for these events.


This has also been published on Linkedin, where there other comments.


About our Guest Author

Allan O'Neil Allan O’Neil has worked in Australia’s wholesale energy markets since their creation in the mid-1990’s, in trading, risk management, forecasting and analytical roles with major NEM electricity and gas retail and generation companies.

He is now an independent energy markets consultant, working with clients on projects across a spectrum of wholesale, retail, electricity and gas issues.

You can view Allan’s LinkedIn profile here.

Allan will be occasionally reviewing market events here on WattClarity

Allan has also begun providing an on-site educational service covering how spot prices are set in the NEM, and other important aspects of the physical electricity market – further details here.

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