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Updated NSW system normal voltage stability limit
Refer to market notice 105936?
The Murraylink Very Fast Runback (VFRB) scheme was modified to increase the capacity of the network due to the increase in generation in the area. The scheme was changed so Murraylink VFRB could be activated / de-activated depending on the time of day on the monitored 220kV lines in north-west Victoria.?
Transgrid has advised AEMO on a revision to the X5 voltage collapse limit with this change to VFRB. This will now be managed by two limits.?
The following constraint equation changes will be implemented at 0900 hrs on Thursday 16th March 2023:
N^^N_NIL_X5_BEKG (replaces N^^N_NIL_3)
N^^N_NIL_X5_BESH (new)?
For full details on the factors on constraint equations and all the constraint equation changes - these have now been loaded into AEMO's pre-production systems.?
Ben Blake
AEMO Operations
Update to system strength requirements in North Queensland
Refer to market notice 102074
AEMO and Powerlink are continuing to investigate system strength requirements in North Queensland.
Due to commissioning of Kaban wind farm in Far North Queensland, the system normal equations have been revised to include following combinations.
-If Stanwell >=2, Stanwell + Calllide >=3, Gladstone >= 1, Stanwell + Callide + Gladstone >= 7, Kareeya >=0, Haughton Syncon status = ON/OFF, North Queensland load >=250 MW,
Ross+FNQ load >=100 MW, limit Kaban Windfarm to 100% (with Haughton Syncon ON), 0% (with Haughton Syncon Syncon OFF) and no limit to other NQLD Plants.
A revision to the constraint equations will be implemented at 1400 hrs on Wednesday 1st March 2023.
The new combinations have now published in a limits advice document on AEMO's website. For more information refer to the new limits advice: https://www.aemo.com.au/energy-systems/electricity/national-electricity-market-nem/system-operations/congestion-information-resource/limits-advice
This advice contains all the combinations for Queensland for system normal cases. Additional information has been included in the limit advice to clarify the requirement to disconnect all inverters/turbines under certain system conditions.
The constraint equation in the Q-NIL set of the form below will be modified:
Q_NIL_STRGTH_XXXX
Q_NIL_STRGTH_XXXX_I
AEMO Operations
Changes to Murraylink Very Fast Runback and constraints in Victoria
The Murraylink Very Fast Runback (VFRB) scheme is being modified to increase the capacity of the network due to the increase in generation in the area. The scheme will be changed so Murraylink VFRB can be activated / de-activated depending on the time of day on the monitored 220kV lines in north-west Victoria.
The changes to the scheme will be activated and constraint equaiton modified at 1200hrs Monday 20th February 2023. The following system normal constraint equations will be modified:
V^^V_NIL_KGTS
V^^V_NIL_KGTS_2
V>>SML_NIL_7A
V>>SML_NIL_7B
V>>SML_NIL_7C
V>>V_NIL_13
V>>V_NIL_14
V>>V_NIL_20
V>>V_NIL_21
V>>V_NIL_22
V>>V_NIL_23
V>>V_NIL_24
V>>V_NIL_25
V>>V_NIL_26
V>>V_NIL_26_1
V>>V_NIL_26A
V>>V_NIL_26A_1
For full details on the factors on constraint equations and all the constrint equation changes - these have now been loaded into AEMO's pre-production systems.
Ben Blake
AEMO Operations
Non-credible contingency event - Qld Region - 13/02/2023
Non-credible contingency event - Qld Region - 13/02/2023
At 1402 hrs 13/02/2023 the H77 Columboola - H76 Wandoan South No. 8891 and No. 8892 275 kV Lines tripped, also affecting supply west of H79 Yuleba North and H80 Eurombah.
AEMO did not instruct load shedding.
Approximately 390 MW of Load interrupted and 114 MW of Generation interrupted.
The cause of this non credible contingency event is not known at this stage.
Manager NEM Real Time Operations
Non-credible contingency event - Qld Region - 03/02/2023
Non-credible contingency event - Qld Region - 03/02/2023
At 1722 hrs 03/02/2023 the Kareeya Power Station Unit 1, Unit 2 and Unit 4 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
Update - Non-credible contingency event - Vic region - 11/12/2022
Update - Non-credible contingency event - Vic region - 11/12/2022
Refer AEMO ELECTRICITY MARKET NOTICE 104353
At 1157 hrs the Kerang - Wemen - Red Cliffs 220 kV Line and the Kiamal Solar Farm STX transformer (Kiamal synchronous condenser) tripped.
AEMO did not instruct load shedding.
AEMO has been advised of disconnection of bulk electrical load (27 MW)
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 - 11/12/2022
Non-credible contingency event - Vic region - 11/12/2022
At 1157 hrs the Kerang - Wemen - Red Cliffs 220 kV Line and the Kiamal Solar Farm STX transformer (Kiamal synchronous condenser) tripped.
AEMO did not instruct load shedding.
AEMO is still waiting to be 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 - Vulnerable lines in Qld region
Update - Lightning vulnerable lines in Qld region
Refer to AEMO Electricity Market Notice 103958 and 103959
At 1913 hrs Chalumbin - Turkinje No.7165 132 kV and Chalumbin - Turkinje No.7166 132 kV Lines tripped and auto-reclosed.
The cause of the trip was identified as due to lightning.
In accordance with SO_OP_3715, AEMO now considers the Chalumbin - Turkinje No.7165 132 kV and Chalumbin - Turkinje No.7166 132 kV lines to be vulnerable with a category of probable due to lightning.
Manager NEM Real Time Operations
Non-credible contingency event - Qld region - 25/11/2022
Non-credible contingency event - Qld region - 25/11/2022
At 1913 hrs the Chalumbin - Turkinje 7165 and 7166 132 kV Lines tripped and auto-reclosed.
AEMO did not instruct load shedding.
Approximately 75 MW of load was interrupted during the auto-reclose time.
The cause of this non credible contingency event is not known at this stage.
Manager NEM Real Time Operations