AEMO ELECTRICITY MARKET NOTICE.

AEMO has identified that a non-credible contingency event impacting the power system is more likely to occur and is considered reasonably possible because of the existence of widespread abnormal conditions namely severe weather in the SA region.

AEMO has therefore reclassified the occurrence of a non-credible contingency event involving multiple plant due to these abnormal conditions as credible.

AEMO has taken the following action(s) to maintain power system security at 0850 hrs 25/07/2025.

Constraint set(s) invoked:
I-VS_250

Duration: 0850 hrs until further notice

Need for further measures is being monitored and further measures may be implemented in line with the Power System Security Guidelines (SO_OP_3715).

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE.

Reclassification of a non-credible contingency event as a credible contingency event due to severe weather warning.
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: SA
Lines: Para-Templers West and Magill-Torrens Island A 275kV lines
Duration: 0115 hrs 25/07/2025 until further notice
Constraint set(s) invoked: Nil

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE.

Reclassification of a non-credible contingency event as a credible contingency event due to severe weather warning.
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: SA
Lines: Brinkworth-Davenport, Brinkworth-Templers West and Para-Templers West 275kV lines
Duration: 0115 hrs 25/07/2025 until further notice
Constraint set(s) invoked: Nil

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: VIC1

Lines: Yallourn - Rowville 7 220 kV and Yallourn - Rowville 8 220 kV

Cancellation time: 23/07/2025 23:29

Constraint set(s) revoked:
V-ROYP78_R_N-2 Constraint set contains the following interconnector(s) on the left hand side:
NONE


Refer AEMO Electricity Market Notice 128293

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: Guybal Munjan - Chalumbin 857 275kV line and Guybal Munjan - Chalumbin 858 275kV line

Cancellation time: 23/07/2025 22:29

Constraint set(s) revoked:
Q-RSCH_N-2 Constraint set contains the following interconnector(s) on the left hand side:
NONE


Refer AEMO Electricity Market Notice 128292

Auto-generated on behalf of 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: Yallourn - Rowville 7 220 kV and Yallourn - Rowville 8 220 kV

Duration: 23/07/2025 22:27 until further notice

Constraint set(s) invoked:
V-ROYP78_R_N-2 Constraint set contains the following interconnector(s) on the left hand side:
NONE


Auto-generated on behalf of 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: QLD1

Lines: Guybal Munjan - Chalumbin 857 275kV line and Guybal Munjan - Chalumbin 858 275kV line

Duration: 23/07/2025 19:27 until further notice

Constraint set(s) invoked:
Q-RSCH_N-2 Constraint set contains the following interconnector(s) on the left hand side:
NONE


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: Guybal Munjan - Chalumbin 857 275kV line and Guybal Munjan - Chalumbin 858 275kV line

Cancellation time: 23/07/2025 17:04

Constraint set(s) revoked:
Q-RSCH_N-2 Constraint set contains the following interconnector(s) on the left hand side:
NONE


Refer AEMO Electricity Market Notice 128288

Auto-generated on behalf of 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: QLD1

Lines: Guybal Munjan - Chalumbin 857 275kV line and Guybal Munjan - Chalumbin 858 275kV line

Duration: 23/07/2025 16:02 until further notice

Constraint set(s) invoked:
Q-RSCH_N-2 Constraint set contains the following interconnector(s) on the left hand side:
NONE


Auto-generated on behalf of Manager NEM Real Time Operations