Filter by:
Filter by category
Filter by Date
From
To
83081CONSTRAINTS01/03/2021 03:49:15 PM
Update - Reclassification of a Non-Credible Contingency Event in Tasmania Region
AEMO ELECTRICITY MARKET NOTICE
Update - Reclassification of a Non-Credible Contingency Event in TAS Region:
Trip of any Tasmanian Transmission Line and Basslink Interconnector
Refer to AEMO Electricity market notices 47360, 47855 and 53957.
In Dec 2014 AEMO reclassified the loss of any transmission line in Tasmania and Basslink Interconnector to be a credible contingency event, for Basslink flow in the direction of Victoria to Tasmania only. This was subsequently updated to exclude faults on either of the two George Town to Pacific Aluminium 220 kV transmission lines or the George Town to Tamar Valley power station 220 kV transmission line in Jan 2015 and Jun 2016 respectively.
Following a power system event in Tasmania on 29/11/2020, and based on updated information from Market Participants, AEMO has further modified this reclassification.
AEMO will now reclassify the loss of any transmission line in Tasmania and Basslink Interconnector to be a credible contingency event, for Basslink flow in the direction of Victoria to Tasmania only.
As a consequence of this reclassification, AEMO will modify the frequency control ancillary service (FCAS) requirements for Tasmania to all require Contingency FCAS services to be sourced from within Tasmania, for Basslink flow in the direction of Victoria to Tasmania.
The following constraint equations will be updated for the above change at 1300hrs Wednesday 3rd March 2020:
F_T++NIL_ML_L5
F_T++NIL_ML_L6
F_T++NIL_ML_L60
F_T++NIL_TL_L5_DS
F_T++NIL_TL_L6_DS
F_T++NIL_TL_L60_DS
F_T+NIL_ML_L5
F_T+NIL_ML_L6
F_T+NIL_ML_L60
F_T+NIL_TL_L5_DS
F_T+NIL_TL_L6_DS
F_T+NIL_TL_L60_DS
Ben Blake
AEMO Operations
Update - Reclassification of a Non-Credible Contingency Event in TAS Region:
Trip of any Tasmanian Transmission Line and Basslink Interconnector
Refer to AEMO Electricity market notices 47360, 47855 and 53957.
In Dec 2014 AEMO reclassified the loss of any transmission line in Tasmania and Basslink Interconnector to be a credible contingency event, for Basslink flow in the direction of Victoria to Tasmania only. This was subsequently updated to exclude faults on either of the two George Town to Pacific Aluminium 220 kV transmission lines or the George Town to Tamar Valley power station 220 kV transmission line in Jan 2015 and Jun 2016 respectively.
Following a power system event in Tasmania on 29/11/2020, and based on updated information from Market Participants, AEMO has further modified this reclassification.
AEMO will now reclassify the loss of any transmission line in Tasmania and Basslink Interconnector to be a credible contingency event, for Basslink flow in the direction of Victoria to Tasmania only.
As a consequence of this reclassification, AEMO will modify the frequency control ancillary service (FCAS) requirements for Tasmania to all require Contingency FCAS services to be sourced from within Tasmania, for Basslink flow in the direction of Victoria to Tasmania.
The following constraint equations will be updated for the above change at 1300hrs Wednesday 3rd March 2020:
F_T++NIL_ML_L5
F_T++NIL_ML_L6
F_T++NIL_ML_L60
F_T++NIL_TL_L5_DS
F_T++NIL_TL_L6_DS
F_T++NIL_TL_L60_DS
F_T+NIL_ML_L5
F_T+NIL_ML_L6
F_T+NIL_ML_L60
F_T+NIL_TL_L5_DS
F_T+NIL_TL_L6_DS
F_T+NIL_TL_L60_DS
Ben Blake
AEMO Operations
82983CONSTRAINTS23/02/2021 02:33:12 PM
Updates to system normal voltage collapse constraint equations in south-west NSW
AEMO ELECTRICITY MARKET NOTICE
Refer to market notices 75618 and 80103
TransGrid has advised AEMO of an update to the voltage collapse limit in south-west NSW for loss of Darlington Point to Wagga (63) 330 kV line. The limit will now include a term for Darlington Point solar farm inverters.
Additionally, AEMO has reviewed the operating margins for the two voltage collapse constraint equations in south-west NSW. The operating margin for N^^N_NIL_2 will be reduced from 45 to 30 and N^^N_NIL_3 reduced from 30 to 10.
The following constraint equations will be updated with the above changes at 1000 hrs Wednesday 24th February 2021.
N^^N_NIL_2
N^^N_NIL_3
For further details on these constraint equation please contact ben.blake@aemo.com.au
Ben Blake
AEMO Operations
Refer to market notices 75618 and 80103
TransGrid has advised AEMO of an update to the voltage collapse limit in south-west NSW for loss of Darlington Point to Wagga (63) 330 kV line. The limit will now include a term for Darlington Point solar farm inverters.
Additionally, AEMO has reviewed the operating margins for the two voltage collapse constraint equations in south-west NSW. The operating margin for N^^N_NIL_2 will be reduced from 45 to 30 and N^^N_NIL_3 reduced from 30 to 10.
The following constraint equations will be updated with the above changes at 1000 hrs Wednesday 24th February 2021.
N^^N_NIL_2
N^^N_NIL_3
For further details on these constraint equation please contact ben.blake@aemo.com.au
Ben Blake
AEMO Operations
82947CONSTRAINTS22/02/2021 11:10:12 AM
Update to Vic to SA transient and voltage collapse limits
AEMO ELECTRICITY MARKET NOTICE
Electranet has reviewed the system normal transient and voltage stability Heywood limits from Victoria to South Australia. The revised limits take into account improved distributed rooftop PV trip calcuations for the limits equations.
The revised limits equations will be implemented to the following equations at 1000 hrs Tuesday 23rd February 2021.
V::S_NIL_TBSE_1
V::S_NIL_TBSE_2
V^^S_NIL_TBSE_1
V^^S_NIL_TBSE_2
V^^S_NIL_MAXG_1
V^^S_NIL_MAXG_2
V^^S_NIL_MAXG_3
V::S_NIL_MAXG_1
V::S_NIL_MAXG_2
V::S_NIL_MAXG_3
For further details on this constraint equation please contact diyoni.hoole@aemo.com.au
Diyoni Hoole
AEMO Operations
Electranet has reviewed the system normal transient and voltage stability Heywood limits from Victoria to South Australia. The revised limits take into account improved distributed rooftop PV trip calcuations for the limits equations.
The revised limits equations will be implemented to the following equations at 1000 hrs Tuesday 23rd February 2021.
V::S_NIL_TBSE_1
V::S_NIL_TBSE_2
V^^S_NIL_TBSE_1
V^^S_NIL_TBSE_2
V^^S_NIL_MAXG_1
V^^S_NIL_MAXG_2
V^^S_NIL_MAXG_3
V::S_NIL_MAXG_1
V::S_NIL_MAXG_2
V::S_NIL_MAXG_3
For further details on this constraint equation please contact diyoni.hoole@aemo.com.au
Diyoni Hoole
AEMO Operations
82819CONSTRAINTS10/02/2021 12:25:04 PM
Update to Vic to NSW voltage collapse limit
AEMO ELECTRICITY MARKET NOTICE
Refer to Market Notice 78621
AEMO has completed a further review of the system normal voltage stability limit for loss of all APD potlines for flows from Victoria to New South Wales. The revised limit is the result of improved reactive modelling in southern NSW which could potentially mean higher transfers into NSW under some generation/load scenarios.
The revised constraint equation includes generators in southern NSW and hydro generation at Mt. Beauty on the left-hand side as well as VIC1-NSW1. Full details on the limits advice are to be published on 11/02/2021 on the AEMO website: https://aemo.com.au/energy-systems/electricity/national-electricity-market-nem/system-operations/congestion-information-resource/limits-advice
The constraint is most likely to bind when there is low Vic demands and high transfers to NSW. When it binds it will restrict Vic to NSW transfers and Hume NSW unit.
This revised limit will be implemented to the following constraint equation at 1000 hrs Thursday 11th February 2021.
V^^N_NIL_1
For further details on this constraint equation please contact terry.liu@aemo.com.au
Terry Liu
AEMO Operations
Refer to Market Notice 78621
AEMO has completed a further review of the system normal voltage stability limit for loss of all APD potlines for flows from Victoria to New South Wales. The revised limit is the result of improved reactive modelling in southern NSW which could potentially mean higher transfers into NSW under some generation/load scenarios.
The revised constraint equation includes generators in southern NSW and hydro generation at Mt. Beauty on the left-hand side as well as VIC1-NSW1. Full details on the limits advice are to be published on 11/02/2021 on the AEMO website: https://aemo.com.au/energy-systems/electricity/national-electricity-market-nem/system-operations/congestion-information-resource/limits-advice
The constraint is most likely to bind when there is low Vic demands and high transfers to NSW. When it binds it will restrict Vic to NSW transfers and Hume NSW unit.
This revised limit will be implemented to the following constraint equation at 1000 hrs Thursday 11th February 2021.
V^^N_NIL_1
For further details on this constraint equation please contact terry.liu@aemo.com.au
Terry Liu
AEMO Operations
82115CONSTRAINTS13/01/2021 08:37:07 AM
Update to Voltage Stability limits for Murraylink transfers from South Australia to Victoria
AEMO ELECTRICITY MARKET NOTICE
ElectraNet has advised AEMO of revised voltage stability limits for Murraylink transfers from South Australia to Victoria.
Refer to Market Notice 82079.
The existing limit of 160 MW on Murraylink will be replaced with two voltage stability limits. Only one of the limits would apply depending on whether or not the Monash capacitor banks are available and in-service for switching.
The following constraint sets and equations will be implemented at 1000 hrs Wednesday 13th January 2021:
- constraint set S-NIL containing constraint equation SVML^NIL_MH-CAP_ON.
- constraint set S-MH_CAP (renamed from S-NIL_MN-CAP_OFF) containing constraint SVML^MH-CAP_OFF (renamed from SVML^NIL_MH-CAP_OFF).
Constraint set S-NIL will remain invoked at all times.
Constraint set S-MH_CAP will only be invoked when Monash Capacitors are not available for switching and are out of service or if one or both capacitors are out of service.
The existing equation SVML^NIL_160 in the S-NIL set will be removed.
For full details on the factors these constraint equations have now been loaded into AEMO's pre-production systems.
For further details on these new constraint equations please contact diyoni.hoole@aemo.com.au.
Diyoni Hoole
AEMO Operations
ElectraNet has advised AEMO of revised voltage stability limits for Murraylink transfers from South Australia to Victoria.
Refer to Market Notice 82079.
The existing limit of 160 MW on Murraylink will be replaced with two voltage stability limits. Only one of the limits would apply depending on whether or not the Monash capacitor banks are available and in-service for switching.
The following constraint sets and equations will be implemented at 1000 hrs Wednesday 13th January 2021:
- constraint set S-NIL containing constraint equation SVML^NIL_MH-CAP_ON.
- constraint set S-MH_CAP (renamed from S-NIL_MN-CAP_OFF) containing constraint SVML^MH-CAP_OFF (renamed from SVML^NIL_MH-CAP_OFF).
Constraint set S-NIL will remain invoked at all times.
Constraint set S-MH_CAP will only be invoked when Monash Capacitors are not available for switching and are out of service or if one or both capacitors are out of service.
The existing equation SVML^NIL_160 in the S-NIL set will be removed.
For full details on the factors these constraint equations have now been loaded into AEMO's pre-production systems.
For further details on these new constraint equations please contact diyoni.hoole@aemo.com.au.
Diyoni Hoole
AEMO Operations
82079CONSTRAINTS12/01/2021 06:12:01 AM
Update to Voltage Stability limits for Murraylink transfers from South Australia to Victoria
AEMO ELECTRICITY MARKET NOTICE
ElectraNet has advised AEMO of revised voltage stability limits for Murraylink transfers from South Australia to Victoria.
The existing limit of 160 MW on Murraylink will be replaced with two voltage stability limits. Only one of the limits would apply depending on whether or not the Monash capacitor banks are available and in-service for switching.
The following constraint sets and equations will be implemented at 1000 hrs Wednesday 13th January 2021:
- constraint set S-NIL containing constraint equation SVML^NIL_MH-CAP_ON.
- constraint set S-NIL_MN-CAP_OFF containing constraint SVML^NIL_MH-CAP_OFF.
Constraint set S-NIL will remain invoked at all times.
Constraint set S-NIL_MN-CAP_OFF will only be invoked when Monash Capacitors are not available for switching and are out of service.
The existing equation SVML^NIL_160 in the S-NIL set will be removed.
For full details on the factors these constraint equations have now been loaded into AEMO's pre-production systems.
For further details on these new constraint equations please contact diyoni.hoole@aemo.com.au.
Diyoni Hoole
AEMO Operations
ElectraNet has advised AEMO of revised voltage stability limits for Murraylink transfers from South Australia to Victoria.
The existing limit of 160 MW on Murraylink will be replaced with two voltage stability limits. Only one of the limits would apply depending on whether or not the Monash capacitor banks are available and in-service for switching.
The following constraint sets and equations will be implemented at 1000 hrs Wednesday 13th January 2021:
- constraint set S-NIL containing constraint equation SVML^NIL_MH-CAP_ON.
- constraint set S-NIL_MN-CAP_OFF containing constraint SVML^NIL_MH-CAP_OFF.
Constraint set S-NIL will remain invoked at all times.
Constraint set S-NIL_MN-CAP_OFF will only be invoked when Monash Capacitors are not available for switching and are out of service.
The existing equation SVML^NIL_160 in the S-NIL set will be removed.
For full details on the factors these constraint equations have now been loaded into AEMO's pre-production systems.
For further details on these new constraint equations please contact diyoni.hoole@aemo.com.au.
Diyoni Hoole
AEMO Operations
81296CONSTRAINTS17/12/2020 12:26:52 PM
Update to system strength requirements in North Queensland
AEMO ELECTRICITY MARKET NOTICE
Refer to market notice 80324
AEMO and Powerlink are continuing to investigate system strength requirements in North Queensland.
A revision to the constraint equations will be implemented at 0900 hrs Friday 18th December 2020.
The new combinations are 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.
The constraint equations in the Q-NIL set of the form below will be modified:
Q_NIL_STRGTH_XXX
For further details please contact James Lindley at james.lindley@aemo.com.au or Simon Taylor at businessdevelopment@powerlink.com.au
Mya San
AEMO Operations
Refer to market notice 80324
AEMO and Powerlink are continuing to investigate system strength requirements in North Queensland.
A revision to the constraint equations will be implemented at 0900 hrs Friday 18th December 2020.
The new combinations are 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.
The constraint equations in the Q-NIL set of the form below will be modified:
Q_NIL_STRGTH_XXX
For further details please contact James Lindley at james.lindley@aemo.com.au or Simon Taylor at businessdevelopment@powerlink.com.au
Mya San
AEMO Operations
80672CONSTRAINTS03/12/2020 03:16:11 PM
New FCAS constraint equations for trip of generators in south-west NSW
AEMO ELECTRICITY MARKET NOTICE
In the event of a trip of the Darlington Point to Wagga (63) 330 kV line a number of generators will be tripped via a transfer tripping control scheme. With the increase in generation in south-west NSW AEMO has identified that the total MWs could potentially exceed the largest NSW generating unit. AEMO will implement new FCAS constraint equations to manage this contingency.
The constraint equations include the impacted generators: Broken Hill solar (BROKENH1), Darlington Point (DARLSF1), Limondale 1 (LIMOSF11), Sunraysia (SUNRSF1) and Silverton (STWF1) and regional FCAS requirements the left-hand side.
The following constraint equations will be implemented at 1000 hrs 4th December 2020.
F_I+TTS_TG_R5
F_I+TTS_TG_R6
F_I+TTS_TG_R60
F_MAIN++TTS_TG_R5
F_MAIN++TTS_TG_R6
F_MAIN++TTS_TG_R60
F_MAIN+TTS_TG_R5
F_MAIN+TTS_TG_R6
F_MAIN+TTS_TG_R60
For full details on the factors these constraint equations have now been loaded into AEMO's pre-production systems.
For further details on these new constraint equations please contact ben.blake@aemo.com.au
Ben Blake
AEMO Operations
In the event of a trip of the Darlington Point to Wagga (63) 330 kV line a number of generators will be tripped via a transfer tripping control scheme. With the increase in generation in south-west NSW AEMO has identified that the total MWs could potentially exceed the largest NSW generating unit. AEMO will implement new FCAS constraint equations to manage this contingency.
The constraint equations include the impacted generators: Broken Hill solar (BROKENH1), Darlington Point (DARLSF1), Limondale 1 (LIMOSF11), Sunraysia (SUNRSF1) and Silverton (STWF1) and regional FCAS requirements the left-hand side.
The following constraint equations will be implemented at 1000 hrs 4th December 2020.
F_I+TTS_TG_R5
F_I+TTS_TG_R6
F_I+TTS_TG_R60
F_MAIN++TTS_TG_R5
F_MAIN++TTS_TG_R6
F_MAIN++TTS_TG_R60
F_MAIN+TTS_TG_R5
F_MAIN+TTS_TG_R6
F_MAIN+TTS_TG_R60
For full details on the factors these constraint equations have now been loaded into AEMO's pre-production systems.
For further details on these new constraint equations please contact ben.blake@aemo.com.au
Ben Blake
AEMO Operations
80633CONSTRAINTS02/12/2020 01:09:08 PM
Update to Far North Queensland Voltage Stability limits
AEMO ELECTRICITY MARKET NOTICE
Powerlink has advised AEMO of revised voltage stability limits in Far North Queensland.
The revised limits include
-an update to the existing limit for loss of Woree SVC and a new limit for loss of Mt Emerald Windfarm for system normal condition
-two new limits for network reconfiguration
The network is being reconfigured so existing 132 kV lines can be operated at 275 kV - forming the new Ross to Woree (8966) 275 kV feeder. This temporary arrangement is in place to allow for repairs to the Chalumbin to Woree 275kV (877) line.
The following constraint sets and equations will be implemented at 1300 hrs Thursday 3rd December 2020.
- constraint set Q-NIL_FNQ_NORM containing constraint equations Q^NIL_FNQ_MEWF and Q^NIL_FNQ_WRSVC.
- constraint set Q-NIL_FNQ_RECON containing constraint equations Q^NIL_FNQ_858MEWF and Q^NIL_FNQ_8966.
Only one of the above two sets will be invoked at any one time.
- Q-NIL_FNQ_RECON set will be invoked during Far North Queensland network reconfiguration.
- Q-NIL_FNQ_ NORM set will be invoked upon returning to the previous configuration once the repairs are completed in mid-2021.
The existing equation Q^NIL_FNQ in the Q-NIL set will be removed.
For full details on the factors these constraint equations have now been loaded into AEMO's pre-production systems.
For further details on these new constraint equations please contact mya.san@aemo.com.au.
Mya San
AEMO Operations
Powerlink has advised AEMO of revised voltage stability limits in Far North Queensland.
The revised limits include
-an update to the existing limit for loss of Woree SVC and a new limit for loss of Mt Emerald Windfarm for system normal condition
-two new limits for network reconfiguration
The network is being reconfigured so existing 132 kV lines can be operated at 275 kV - forming the new Ross to Woree (8966) 275 kV feeder. This temporary arrangement is in place to allow for repairs to the Chalumbin to Woree 275kV (877) line.
The following constraint sets and equations will be implemented at 1300 hrs Thursday 3rd December 2020.
- constraint set Q-NIL_FNQ_NORM containing constraint equations Q^NIL_FNQ_MEWF and Q^NIL_FNQ_WRSVC.
- constraint set Q-NIL_FNQ_RECON containing constraint equations Q^NIL_FNQ_858MEWF and Q^NIL_FNQ_8966.
Only one of the above two sets will be invoked at any one time.
- Q-NIL_FNQ_RECON set will be invoked during Far North Queensland network reconfiguration.
- Q-NIL_FNQ_ NORM set will be invoked upon returning to the previous configuration once the repairs are completed in mid-2021.
The existing equation Q^NIL_FNQ in the Q-NIL set will be removed.
For full details on the factors these constraint equations have now been loaded into AEMO's pre-production systems.
For further details on these new constraint equations please contact mya.san@aemo.com.au.
Mya San
AEMO Operations