Renewable Power Australia – Report: Wind Power Caused The South Australia Blackout

Posted on Thu 10/20/2016 by

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Bolt New 01By Andrew Bolt ~

South Australian Premier Jay Weatherill – along with green energy interests and many journalists – claimed South Australia’s fault had nothing to do with the state’s wind generators. They were telling untruths. A new report into the disaster concludes the blackout was caused by wind farms suddenly going off line, while gas generators didn’t.

South Australian Premier Jay Weatherill, October 6:

What we do know now is despite all of the fearmongering about wind power is that wind power continued to operate throughout the event.

Clements Gap wind plant in South Australia

Clements Gap wind plant in South Australia

Absolutely false.

The Australian Energy Market Operator has now published an update that puts the blame on wind farms.

Thermal power worked fine during the storm, but wind farms failed. Some simply couldn’t work in the high winds, but the real problem was that many were set to stop working after several lightning strikes or line failures. Nine farms  went off line and the triggered such  a sudden and huge  power demand that it tripped the line bring coal-fired power from Victoria and sent the whole state into a blackout:

From the report summary:

In this updated report, it is now known that five system faults occurred within a period of 88 seconds on 28 September 2016, leading to six voltage disturbances.

Data now shows that nine of the 13 wind farms online at the time of the event did not ride through the six voltage disturbances, resulting in a loss of 445 MW of generation. Preliminary discussions with wind farm operators suggest this inability to ride through all disturbances was due to ‘voltage ride-through’ settings set to disconnect or reduce turbine output when between three to six disturbances are detected within a defined time period.

Thermal generators remained connected up until the SA system disconnected from the remainder of the National Electricity Market (NEM). The Heywood Interconnector remained connected up until the sudden increase in electricity flow resulting from the loss of generation caused the automatic protection mechanism to disconnect the lines…

AEMO is continuing to consult with wind farm operators and wind turbine manufacturers to better understand the impact on the power system of their ride through settings. Several wind farms have already implemented revised settings allowing them to ride through a higher number of disturbances.

More detail:

Investigations now show that there was a total sustained reduction of 445 MW of wind generation across nine wind farms, plus further transient reductions of 39 MW in each ride-through event. Thetransient reduction in output was spread across all wind farms online at the time, including those that did not suffer a sustained reduction in output….

The sudden loss of 445 MW of generation increased flows on the Heywood Interconnector [bringing electricity from Victoria]. The Heywood  Interconnector’s automatic protection mechanism operated and disconnected to avoid damage to the interconnector and other transmission network infrastructure in both SA and Victoria…

The instantaneous loss of 900 MW of supply across the Heywood Interconnector could not be met by the generators remaining online within SA. The sudden and large deficit of supply caused the system frequency to collapse more quickly than the Under-Frequency Load Shedding (UFLS) scheme was able to act, resulting in the SA region Black System.

The report notes wind farms tend not to work in the kind of high winds experienced that day:

On the morning of 28 September 2016, the following issues were considered and assessed by AEMO operational staff… It was noted that  the wind conditions could reduce wind farm output where wind conditions exceeded 90km/h (a normal feature of wind farm operation termed ‘overspeed’ trip)….

But this had a relatively minor role:

Approximately 20 MW of wind power was disconnected due to excessive wind during the event.

Lines blew over or were hit by lightning, among other things,  and wind farms were not set to keep going after these disturbances to the system:

Nine wind farms exhibited unexpected power reduction during the six voltage disturbances on the transmission system. AEMO has been working with each wind farm operator to determine the cause s of this reduction, and that engagement is continuing.

From information made available by wind farm operators and turbine manufacturers, AEMO has concluded:

– All SA wind turbines have a control system that takes action if the number of ride-through events in a specific period exceeds a pre-set limit.

– If the pre-set limit was exceeded in the event, each wind turbine either disconnected from the network, stopped operating (remained connected with zero output) or reduced its output.

– The pre-set limit varied from wind farm to wind farm, and some were set low enough for the six voltage disturbances in the event to exceed their limit.

– This control system caused nine wind farms to reduce output when the number of
ride-through events caused by voltage disturbances exceeded the pre-set limits.

But the state’s own gas generators worked perfectly (as did the power from coal-fired generators in Victoria) until the wind-farms tripped the system:

Fault ride-through strategies for synchronous machines are fundamentally different to those for wind turbines and non-synchronous power electronic based devices.

A synchronous machine responds to disturbances by virtue of its physical characteristics (size, mass, rotational inertia) and by the action of its automatic voltage regulator. This  provides fault ride-through capability and network voltage support…

All five synchronous generating units (three at Torrens Island and two at Ladbroke Grove) remained connected until 16:18:16, when the SA transmission system was disconnected from the rest of the NEM. They showed no power reduction prior to this time.

Those five units are all gas-fired. Wind power was the problem.

Andrew Bolt writes for the Herald Sun, Daily Telegraph, and The Advertiser and runs Australia’s most-read political blog. On week nights he hosts The Bolt Report on Sky News at 7pm and his Macquarie Radio show at 8pm with Steve Price.

Read more excellent articles from Andrew Bolt’s Blog . http://blogs.news.com.au/heraldsun/andrewbolt/

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