Not seeing any obvious blip in system frequency (at the time BW02 came offline on Sat 4th Oct 2025) we also looked at the similar outage on Sun 5th Oct 2025.
I was keen to see if there was any noticeable blip in System Frequency resulting from the BW02 unit coming offline on Saturday 4th October 2025 for the brief (two-shift) outage.
Back in July 2025 we saw the AEMO had released this ‘Technical Review of the NEM Frequency Control Landscape’ … but are only noting this here now.
We count the number of days each month when there was at least one 4-second measurement outside the NOFB.
How common is it that mainland frequency deviates outside the NOFB (normal operating frequency band)?
We follow on from A 292MW drop in "Market Demand" in Tasmania, on Saturday 16th August 2025 enlisting this "Part 2" to understand the sequence of events using 4-second data.
We assess whether the trip at Yallourn 2 on 26 August 2025 was large enough to drive a frequency disturbance.
It appears it was unit availability used to set the target for dispatch that went awry, rather than unit output.
Among other aspects, a large dip in solar UIGF aligns with the frequency deviation observed on 19th August 2025.
On Tuesday the 19th of August between 11:45 and 12:20 there was a significant frequency deviation on the mainland.
System frequency shows improved resilience to sudden coal generation events since 2020.
A count of coal generator events indicates large unit trips are less frequent.
In reviewing system frequency on the 16th of June, 2025, we observed a drop that reached below the NOFB.
The measurements indicated frequency ducked just below the NOFB briefly, reaching 49.843 Hz.
At 16:01 on April 10, 2025, a system frequency dip was observed from the Global-Roam frequency logger.
High speed frequency measurements provide a deeper understanding of how the system responded to the unplanned 500kV line outage.
Various authors have shared articles about frequency, frequency control and Regulation FCAS in recent times (including 6 from Linton). Here's three things that jumped out to me in these pieces of analysis.
The faster-moving nature of the FM, with the introduction of FPP, removes predictability in the indicator for frequency performance.
The implementation of the Primary frequency response incentive arrangements rule is driving change in how system frequency is controlled and paid-for. The changes stem from how the NEM will incentivise primary frequency response. 6...
The NEM operates at a frequency of 50 hertz (Hz) which means the alternating current should cycle 50 times a second between positive and negative voltage.