Software settings issue behind SA blackout: AEMO

A manufacturer-configured failsafe mechanism was the cause of last-month’s statewide blackout in South Australia, an investigation by the Australian Energy Market Operator (AEMO) has found.

The AEMO report found that the severe storms triggered five separate system faults within a period of 88 seconds, causing six voltage disturbances.

These disturbances led to the automated disconnection or reduction in power output of nine of the state’s wind farms, taking 445 MW of power out of the grid and starting a cascade effect that severed South Australia from the rest of the grid.

Settings on the control systems of each of these farms were set to trigger these actions if between three and six voltage shocks were detected in a short period, the investigation found. These settings are set by the manufacturer and can be raised.

AEMO announced plans to conduct investigations at a national level to ensure voltage ride-through settings are appropriately set in generators across the country.

AEMO also dismissed suggestions that the intermittent nature of wind energy played any role in the blackout.

“This updated report from AEMO confirms that the intermittent nature of wind energy had nothing to do with the September blackout in South Australia,” SA Energy Minister Tom Koutsantonis said.

“There are a number of political opportunists that now owe South Australians an apology for using this event to pursue their anti-renewables agenda. The catastrophic weather we experienced in South Australia caused a number of serious system faults to our electricity grid, including destroying three out of four of the major transmission lines connecting the north of the state to Adelaide.”

But RenewEconomy notes that AEMO’s report has stirred up controversy from wind farm operators, with some complaining that AEMO is pinning the fault on wind energy itself rather than taking responsibility for a failure to adequately prepare its own systems for such an eventuality.

Image courtesy of denisbin under CC