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Panned outage of Heywood - Mortlake PS 500 kV line in the Victoria region on 21 September 2019
The Heywood - Mortlake PS 500 kV line in the Victoria (VIC) region is planned to be out of service from 0630 hrs to 1800 hrs on 21 September 2019.
A credible contingency event during this planned outage could cause synchronous separation of the South Australia (SA) region from the rest of the NEM. If separation occurs, load may be interrupted due to the operation of the Automatic Under Frequency Load Shedding (AUFLS) scheme in SA.
The credible separation contingency is managed as follows:
- When power transfer is from SA to VIC, contingency lower FCAS will be sourced from SA.
- When power transfer is from VIC to SA, due to the 47-52 Hz island separation frequency band advised by the SA jurisdiction, contingency raise FCAS is not sourced in SA and the AUFLS scheme may respond to low frequency events.
-Power transfer will be restricted sufficiently low on VIC - SA interconnector (Heywood interconnector) to manage system security following the loss of the next contingency.
Forecast capacity reserves in the SA region are currently sufficient to meet electricity demand during the planned outage.
The following constraint sets have been invoked for this outage:
V-X_HY_MO_ML
S-X_BC_CP
I-VS_050
Please note that there is a Moorabool - Mortlake Power Station line outage on 21 September 2019.
Refer to market notice MN69290 and AEMOs Network Outage Schedule (NOS) for further details.
Manish Bhaskar
AEMO Operations
Update: Non-credible contingency event more likely to occur due to existence of abnormal conditions - VIC and SA regions.
AEMO ELECTRICITY MARKET NOTICE.
Refer to AEMO ELECTRICITY MARKET NOTICE 70045
AEMO has identified that a non-credible contingency event is more likely to occur in the South west and Central districts of Victoria and much of the South Australia region because of the existence of abnormal conditions namely severe weather.
As at the time of this notice the criteria for reclassification of any further non-credible contingency events have not been met, however there is a possibility of severe weather impacting multiple transmission elements in its vicinity.
Conditions can change rapidly and potentially impacted plant may change. Further notices will only be published to advise of any reclassification, or when the abnormal conditions have ceased to impact the likelihood of a non-credible event occurring.
The following constraint sets are invoked from 0830 hrs 19/09/2019:
Constraint Set: I-SV_250 to remain invoked until 2000hrs 19/09/2019
Constraint Set: I-VS_250 to remain invoked until 2000hrs 19/09/2019.
The constraint sets contains the following interconnector on the left hand side.
V-SA
Manager NEM Real Time Operations
Non-credible contingency event more likely to occur due to existence of abnormal conditions - Vic and SA region.
Non-credible contingency event more likely to occur due to existence of abnormal conditions - Vic and SA region.
AEMO ELECTRICITY MARKET NOTICE.
AEMO has identified that a non-credible contingency event is more likely to occur in the South west and Central districts of Victoria and much of the South Australia region because of the existence of abnormal conditions namely severe weather.
As at the time of this notice the criteria for reclassification of any further non-credible contingency events have not been met, however there is a possibility of severe weather impacting multiple transmission elements in its vicinity.
Conditions can change rapidly and potentially impacted plant may change. Further notices will only be published to advise of any reclassification, or when the abnormal conditions have ceased to impact the likelihood of a non-credible event occurring.
Manager NEM Real Time Operations
Daily planned outage of Moorabool - Tarrone 500 kV line in the Victoria region from 29 October to 03 November 2019
The Moorabool - Tarrone 500 kV line in the Victoria (VIC) region is planned to be out of service from 0700 hrs to 1700 hrs on the following dates:
-29/10/2019
-30/10/2019
-31/10/2019
-01/11/2019
-02/11/2019
-03/11/2019
A credible contingency event during this planned outage could cause synchronous separation of the South Australia (SA) region from the rest of the NEM. If separation occurs, load may be interrupted due to the operation of the Automatic Under Frequency Load Shedding (AUFLS) scheme in SA.
The credible separation contingency is managed as follows:
- When power transfer is from SA to Victoria, contingency lower FCAS will be sourced from SA.
- When power transfer is from Victoria to SA, due to the 47-52Hz island separation frequency band advised by the SA jurisdiction, contingency raise FCAS is not sourced in SA and the AUFLS scheme may respond to low frequency events.
- Power transfer will be restricted on Victoria - South Australia interconnector (Heywood interconnector) to manage system security following the loss of the next contingency.
Forecast capacity reserves in the SA region are currently sufficient to meet electricity demand during the planned outage.
The following constraint sets have been invoked for this outage:
I-VS_050
S-X_BC_CP
V-MLTR
Refer AEMO Network Outage Schedule (NOS) for further details.
Mya San
AEMO Operations
Daily planned outages of Heywood - Tarrone 500 kV line in the Victoria region on 26 and 30 September 2019
The Heywood - Tarrone 500 kV line in the Victoria (VIC) region is planned to be out of service as follow:
-26/09/2019 from 0630 to 1800 hrs
-30/09/2019 from 0630 to 1800 hrs
A credible contingency event during this planned outages could cause synchronous separation of the South Australia (SA) region from the rest of the NEM. If separation occurs, load may be interrupted due to the operation of the Automatic Under Frequency Load Shedding (AUFLS) scheme in SA.
The credible separation contingency is managed as follows:
- When power transfer is from SA to Victoria, contingency lower FCAS will be sourced from SA.
- When power transfer is from Victoria to SA, due to the 47-52Hz island separation frequency band advised by the SA jurisdiction, contingency raise FCAS is not sourced in SA and the AUFLS scheme may respond to low frequency events.
- Power transfer will be restricted on Victoria - South Australia interconnector (Heywood interconnector) to manage system security following the loss of the next contingency.
Forecast capacity reserves in the SA region are currently sufficient to meet electricity demand during the planned outage.
The following constraint sets have been invoked for outage of Heywood - Tarrone 500 kV line.
I-VS_050
S-X_BC_CP
V-HYTR
Refer AEMO Network Outage Schedule (NOS) for further details.
Mya San
AEMO Operations
Maintain the power system in a secure operating state in the Victoria and NSW regions
On 13/09/2019 at 1200 hrs AEMO has invoked the following constraint set to maintain the power system in a secure operating state in the Victoria and NSW regions.
Constraint Set: I-NIL_NW_SW_RISK from 1200 hrs 13/09/2019.
Further notices will only be published to advise of any additional limitations.
Manager NEM Real Time Operations
Cancellation : Contingency event more likely to occur due to existence of abnormal conditions - Victoria region.
AEMO ELECTRICITY MARKET NOTICE.
Abnormal conditions advised in AEMO Electricity Market Notice 69923 have ceased to impact the likelihood of a contingency event occurring as at 1110 hrs 09/12/2019.
Constraint set revoked:
I-NIL_NW_SW_RISK
Manager NEM Real Time Operations
Contingency event more likely to occur due to abnormal conditions - Victoria region.
AEMO has identified that abnormal conditions exist in the Victoria region, namely severe weather which increases the risk of a contingency event occurring in the Victoria weather forecast districts Mallee and North Country.
Given the increased risk, AEMO has applied the following constraint to manage the impact of any such contingency event:
I-NIL_NW_SW_RISK from 1030hrs 12/09/2019.
Further notices will only be published to advise of any additional limitations, or when the abnormal conditions have ceased to impact the likelihood of a contingency event occurring.
Manager NEM Real Time Operations
Reduction in load relief for mainland regions - 12 September 2019
On 12th September at 1100hrs AEMO will reduce the load relief used in the FCAS constraint equations from 1.5% to 1.4% for all mainland regions. This will increase the amount of contingency FCAS enabled by AEMO.
This change is a part of AEMO's review of frequency in the NEM. The mainland load relief will be slowly reduced from the current 1.5%. Details were provided to market participants in an industry teleconference on 16 August 2019. For more information refer to: https://www.aemo.com.au/Electricity/National-Electricity-Market-NEM/Security-and-reliability/Ancillary-services/Load-relief
There will be no change at this stage to the Tasmanian load relief.
The next change is planned for 26th September.
Ben Blake
AEMO Operations