Market Notices

AEMO ELECTRICITY MARKET NOTICE

Reclassification of a Non-Credible Contingency Event as a Credible Contingency Event due to Lightning. AEMO considers the simultaneous trip of the following circuits to now be more likely and reasonably possible. Accordingly AEMO has reclassified it as a credible contingency event.

Region: VIC1

Lines: Eildon PS - Mt Beauty No.1 220 kV and Eildon PS - Mt Beauty No.2 220 kV

Duration: 29/03/2019 12:21 until further notice

Constraint set(s) invoked:
NONE

Auto-generated on behalf of Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE

Update - Possible intervention to manage power system security in South Australia (SA) Region 29/03/2019

Refer AEMO Electricity Market Notice 67924

The synchronous generating units expected to be synchronised in SA from 0030 hrs 30/03/2019 to 1000 hrs 30/03/2019 in Pre-dispatch published at 1100 hrs 29/03/2019 are inadequate to maintain sufficient system strength in SA and hence a secure operating state.

AEMO currently estimates that, in the absence of sufficient market response by 1330 hrs 29/03/2019, AEMO may need to intervene by issuing a direction requiring one or more SA synchronous generating unit(s) to operate or remain synchronised to maintain power system security in SA.

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE

Reclassification of a Non-Credible Contingency Event as a Credible Contingency Event due to Lightning. AEMO considers the simultaneous trip of the following circuits to now be more likely and reasonably possible. Accordingly AEMO has reclassified it as a credible contingency event.

Region: VIC1

Lines: Dederang - Glenrowan No.1 220 kV and Dederang - Glenrowan No.3 220 kV

Duration: 29/03/2019 10:58 until further notice

Constraint set(s) invoked:
V-DDGN_N-2 Constraint set contains the following interconnector(s) on the left hand side:
V-S-MNSP1
V-SA
VIC1-NSW1


Auto-generated on behalf of Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE.

Non-credible contingency event - SA region - 29/03/2019

At 0815 hrs the Ardrossan West - Dalrymple 132 kV Line tripped at Dalrymple end only, Dalrymple No1 and No2 Transformers tripped and Dalrymple -Wattle Point 132 kV Line 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 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

AEMO ELECTRICITY MARKET NOTICE

Cancellation of reclassification of a Non-Credible Contingency Event as a Credible Contingency Event due to Lightning. AEMO considers the simultaneous trip of the following circuits is no longer reasonably possible. There is no longer any lightning activity in the vicinity of the following lines. Accordingly its classification has reverted to a non-credible contingency event.

Region: QLD1

Lines: Ross - Chalumbin No.857 275 kV and Ross - Chalumbin No.858 275 kV

Cancellation time: 29/03/2019 07:54

Constraint set(s) revoked:
NONE

Refer AEMO Electricity Market Notice 67920

Auto-generated on behalf of Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE

Cancellation of reclassification of a Non-Credible Contingency Event as a Credible Contingency Event due to Lightning. AEMO considers the simultaneous trip of the following circuits is no longer reasonably possible. There is no longer any lightning activity in the vicinity of the following lines. Accordingly its classification has reverted to a non-credible contingency event.

Region: QLD1

Lines: Chalumbin - Turkinje No.7165 132 kV and Chalumbin - Turkinje No.7166 132 kV

Cancellation time: 29/03/2019 05:54

Constraint set(s) revoked:
NONE

Refer AEMO Electricity Market Notice 67921

Auto-generated on behalf of Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE.

Cancellation of the reclassification of a Non-Credible contingency event as a Credible contingency event. AEMO considers the simultaneous trip of the following circuits is no longer reasonably possible. 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. Accordingly its classification has reverted to a non-credible contingency event.

Region: Qld

Lines: Tully - Cardwell No. 7389 132kV line and the Yabulu South - Ingham South No. 7133 132kV line at the Ingham South end

Cancellation time: 0230 hrs 29/03/2019

Constraint set(s) revoked:
Nil

Refer AEMO Electricity Market Notices 67925 and 67926.

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE.

Reclassification of a Non-Credible Contingency Event as a Credible Contingency Event. AEMO considers the simultaneous trip of the following circuits to now be more likely and reasonably possible. Accordingly AEMO has reclassified it as a credible contingency event.

Region: Qld

Lines: Tully - Cardwell No. 7389 132kV line and the Yabulu South - Ingham South No. 7133 132kV line at the Ingham South end only

Duration: 2100 hrs until further notice

Constraint set(s) invoked:
Nil

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE.

Non-credible contingency event - Qld region - 28/03/2019

At 1939 hrs the Tully Cardwell No. 7389 132 kV line tripped and reclosed and the Yabulu South - Ingham South No. 7133 132 kV line tripped at the Ingham South end only.

AEMO did not instruct load shedding.

AEMO has been advised of the disconnection of 14MW of bulk electrical load.

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 has therefore reclassified this event as a credible contingency event until further notice.

Manager NEM Real Time Operations