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Non-credible contingency event - Vic region - 16/06/16
Non-credible contingency event - Vic region - 16/06/16
At 1106 hrs the following plant tripped.
Loy Yang No. 1 and No. 3 500 kV Bus
Hazelwood - Loy Yang No. 2 500 kV Line
Loy Yang No. 1 500/220 kV Transformer
Loy Yang A1 generating unit
AEMO did not instruct load shedding.
AEMO has not been advised of any disconnection of bulk electrical load.
The cause of this non credible contingency event has been identified and AEMO is satisfied that another occurrence of this event is unlikely under the current circumstances.
AEMO will not reclassify this event as a credible contingency event.
Manager NEM Real Time Operations
Cancellation - Reclassification of the loss of Wagga 132kV B bus, the No2 and the No3 330/132kV transformers in NSW region.
Cancellation - Reclassification of the loss of Wagga 132 kV B bus, the No 2 and the No 3 330/132 kV transformers in NSW region - 14/06/2016.
Refer to Electricity Market Notice 53874 and 53888
Based on advice from the asset owner the circumstances that existed in relation to the tripping of the Wagga substation 132 kV B bus, the No2 and the No3 330/132 kV transformers have now been addressed
Therefore AEMO no longer considers the simultaneous trip of the Wagga substation 132 kV B bus, the No2 and the No3 330/132 kV transformers to be a credible contingency event from 1055 hrs 14/06/2016 .
Manager NEM Real Time Operations
Update - Reclassification of a Non-Credible Contingency Event in TAS Region
Update - Reclassification of a Non-Credible Contingency Event in TAS Region:
Trip of any Tasmanian Transmission Line and Basslink Interconnector for Basslink flow in the direction of Victoria to Tasmania
Refer to MN 47360 issued 19/12/2014 and MN 47855 issued 23/01/2015.
Advice provided to AEMO indicates that Basslink is unlikely to trip for 220 kV transmission faults close to George Town. As the George Town to Tamar Valley power station 220 kV lines are very short it is unlikely that Basslink will trip for a fault on these lines.
Based on this advice AEMO has reclassified the loss of any transmission line in Tasmania and Basslink Interconnector to be a credible contingency event for Basslink flow in the direction of Victoria to Tasmania only, except for faults on either of the two George Town to Pacific Aluminium 220 kV transmission lines or the George Town to Tamar Valley power station 220 kV transmission line, from 1151 hrs 13/06/2016 until further notice.
Manager NEM Real Time Operations
Reclassification of the loss of Wagga 132kV B bus, No2 and No3 transformer as a credible event 11 June 2016
Refer AEMO ELECTRICITY MARKET NOTICE 53874
At 0950 hrs on 11/06/16, the Wagga substation 132kV B bus, the No2 and the No3 330/132kV transformers tripped.
The cause of this non credible contingency event is not known at this stage.
AEMO is not satisfied that this non credible event is unlikely to re-occur.
AEMO therefore classifies this event as being a credible contingency event.
The No3 330/132kV transformer and the bus were placed on load from 1430hrs, the No2 330/132kV transformer remains de-energised.
Manager NEM Real Time Operations
Non-credible contingency event - NSW region - 11 June 2016
Non-credible contingency event - NSW region - 11 June 2016
At 0950 hrs the Wagga substation 132kV B bus, the No2 and the No3 330/132kV transformers tripped.
AEMO did not observe any reduction in electrical demand
AEMO did not instruct load shedding.
AEMO has not been advised of any disconnection of bulk electrical load.
The cause of this non credible contingency event is not known at this stage.
Manager NEM Real Time Operations
Update - Non-Credible Contingency Event - Vic Region - 8 June 2016
Update - Non-credible contingency event - Victoria region - 8 June 2016
Update to MN 53704
At 0219 hrs the Yallourn No. 2 220 kV bus was returned to service.
The cause of this non-credible contingency event has been identified and AEMO is satisfied that another occurrence of this event is unlikely under the current circumstances.
AEMO will not reclassify this event as a credible contingency event.
Manager NEM Real Time Operations
Non-Credible Contingency Event - Vic Region - 8 June 2016
Non-credible contingency event - Victoria region - 8 June 2016
At 0129 hrs the Yallourn No. 2 220 kV bus tripped.
AEMO did not instruct load shedding.
AEMO has not been advised of any disconnection of bulk electrical load.
The cause of this non credible contingency event is not known at this stage.
Manager NEM Real Time Operations
Non-Credible Contingency Event - Vic Region - Tues 7th Jun 2016
Non-Credible Contingency Event - Vic Region - Tues 7th Jun 2016
At 1610 hrs the Richmond No 2 and No 4 220 kV Buses tripped in the Victoria region.
(Coincident with a planned outage Rowville - Richmond No 1 220 kV Line )
AEMO has not been advised of any disconnection of bulk electrical load.
The cause of this non credible contingency event is known
Manager NEM Real Time Operations
Cancellation of the Reclassification of a Non-Credible Contingency Event: Bouldercombe - Rockhampton 7108 and Bouldercombe - Egans Hill 7221 132 kV Lines in Queensland due to Lightning.
Cancellation of the Reclassification of a Non-Credible Contingency Event: Bouldercombe - Rockhampton 7108 and Bouldercombe - Egans Hill 7221 132 kV Lines in Queensland due to Lightning.
Refer to AEMO Electricity Market Notice no. 53614
There is no longer any Lightning activity in the vicinity of the Bouldercombe - Rockhampton 7108 and Bouldercombe - Egans Hill 7221 132 kV Lines.
AEMO has cancelled the reclassification of the simultaneous trip of those circuits as a credible contingency event at 0235 hrs.
Manager NEM Real Time Operations