AUFLS

We have completed our enquiry into the 12 November 2013 AUFLS activation. The activation resulted from an HVDC commissioning test of Pole 3 and caused 401 MW of lost load. While Transpower, as the grid owner, was found to be the causer of the event; this enquiry focuses on the role of the system operator in approving the HVDC test plans.

The enquiry acknowledges the preparation and planning that the system operator undertook for testing and commissioning Pole 3. The 12 November 2013 AUFLS activation was extremely unfortunate, considering the diligence that the system operator had applied to planning for the tests. The enquiry found that the system operator could improve the way it approves test plans. These improvements would mean that the system operator could identify and more rigorously challenge conclusions made by asset owners (and the assumptions they are based on) when the system operator approves test and commissioning plans.