AEMO ELECTRICITY MARKET NOTICE

To ensure ongoing compliance with the requirements of the Frequency Operating Standards AEMO is procuring additional regulating FCAS across the mainland regions by 20 MW. This will take the quantities procured to 200 MW of raise regulating service and 190 MW of lower regulating service.

This change will be active at 1000 hrs 23 April 2019. The following constraint sets have been invoked:
F-MAIN_LREG_0190
F-MAIN_RREG_0200

AEMO will review power system frequency performance every four weeks, and decide whether to further increase or hold the amount of regulation FCAS procured. AEMO's decision will take into account whether frequency has remained in the NOFB for at least 99.5% of the time over the previous four weeks, together with any other relevant factors.

No change is proposed for the Tasmanian regulation requirements.

For more information refer to the AEMO website:
http://www.aemo.com.au/-/media/Files/Electricity/NEM/Security_and_Reliability/Ancillary_Services/Frequency-and-time-error-reports/Regulation-FCAS-factsheet.pdf
http://www.aemo.com.au/-/media/Files/Electricity/NEM/Security_and_Reliability/Ancillary_Services/Frequency-and-time-error-reports/Regulation-FCAS-changes_April-update.pdf

AEMO Operations

The MTPASA result published on 16 April 2019 identifies no Low Reserve Conditions over the next 2 years.

Please note that MTPASA informs the market of potential reliability issues to allow the market to respond in the first instance, potentially avoiding the need for any market intervention or direction from AEMO.

For further information, please refer to:
https://www.aemo.com.au/Electricity/National-Electricity-Market-NEM/Data/Market-Management-System-MMS/Projected-Assessment-of-System-Adequacy

This notice supersedes Market Notice 68078 published on 9 April 2019.

Background
As part of a broader process of implementing the reliability standard, AEMO runs the Medium Term Projected Assessment of System Adequacy (MTPASA) process weekly to forecast expected unserved energy levels over a two year period. If the expected annual unserved energy exceeds the maximum level specified by the Reliability Standard, a Low Reserve Condition is identified.

For more information about how AEMO implements the reliability standard, please view the Reliability Standard Implementation Guidelines (RSIG) available on AEMO's website at
http://www.aemo.com.au/-/media/Files/Stakeholder_Consultation/Consultations/Electricity_Consultations/2016/EAAP/Reliability-Standard-Implementation-Guidelines.pdf

Forecasting
AEMO

AEMO ELECTRICITY MARKET NOTICE


Refer AEMO Electricity Market Notice 68119

The Hazelwood - South Morang No.1 500 kV Line has been returned to service.

The following constraint set was revoked at 0600 hrs 16/04/2019.

V-HWSM

The constraint set contains equations with the following interconnectors on the LHS.

T-V-MNSP1
V-S-MNSP1
V-SA
VIC1-NSW1

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE

The Hazelwood - South Morang No1 500 kV Line has been de-energised to manage voltages in the Victoria region.

The following constraint set was invoked at 0235 hrs.

V-HWSM

The constraint set contains equations with the following interconnectors on the LHS.

T-V-MNSP
V-S-MNSP1
V-SA
VIC1-NSW1

Refer to AEMO Network Outage Scheduler (NOS) for further details

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE.
Update - Non-credible contingency event - South Australia region - 02/04/2019
Refer AEMO ELECTRICITY MARKET NOTICE MN 68006
At 0136 hrs 02/04/2019 the Brinkworth - Templers West 275 kV Line tripped, coincident with this at Angaston the No. 1 generator 33kV CB 4555 and the No. 2 generator 33kV CB 4552 opened.
The cause of this non credible contingency event is not known.
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.
The Brinkworth - Templers West 275 kV Line was returned to service following this event at 1528hrs 15/04/2019

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE

Refer to AEMO Market Notices 67798

The Moorabool -Tarrone 500 kV line in the Vic region is planned to be out of service from 0700 hrs to 1730 hrs daily on 17/04/2019 and 18/04/2019.

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:

F-V-MLTR
I-VS_050
S-X_BC_CP
V-MACARTHUR_ZERO
V-MLTR

Refer AEMO Network Outage Schedule (NOS) for further details.

Danushka Sooriyadasa
AEMO Operations

AEMO ELECTRICITY MARKET NOTICE

The Tungkillo - Tailem Bend 275kV line in South Australia (SA) region is planned to be out of service from 0900 hrs on 16/04/2019 to 1800 hrs on 16/04/2019.

During this outage, SA will remain connected to the rest of the NEM via the Tailem Bend - Cherry Garden 275kV line and the 132kV network.

A credible contingency event on the Tailem Bend - Cherry Garden 275 kV line during this planned outage will sever the 275kV connections between the NEM and SA. If SA remains connected to the NEM via the 132kV network, this will pose a system security issue.

If this occurs, AEMO will take all necessary steps as outlined in Section 6.1 of SO-OP-3715 Power System Security Guideline to separate the 132kV network and therefore manage an orderly separation of SA from the NEM.

Michael Yang
AEMO Operations

AEMO ELECTRICITY MARKET NOTICE

Cancellation - Inter-regional transfer limit variation: Hazelwood - South Morang No.1 500 kV Line (Vic) - Voltage Control

Refer AEMO Electricity Market Notice 68114

The Hazelwood - South Morang No.2 500 kV Line has been returned to service.

The following constraint set was revoked at 0555 hrs 15/04/2019.
V-HWSM

The constraint set contains equations with the following interconnectors on the LHS.

T-V-MNSP1
V-S-MNSP1
V-SA
VIC1-NSW1

Manager NEM Real Time Operations

AEMO ELECTRICITY MARKET NOTICE

The Hazelwood - South Morang No1 500 kV Line has been de-energised to manage voltages in the Victoria region.

The following constraint set was invoked at 0245 hrs 15/04/2019

V-HWSM

The constraint set contains equations with the following interconnectors on the LHS.

T-V-MNSP
V-S-MNSP1
V-SA
VIC1-NSW1

Refer to AEMO Network Outage Scheduler (NOS) for further details

Manager NEM Real Time Operations