ERCOT Reliability Must Run

ERCOT Reliability Must

Run

Protocol Definition

Reliability Must Run (RMR) Unit(ERCOT Protocols Section 2: Definitions and Acronyms July 31, 2002)

A Generation Resource unit operated under the terms of an annual Agreement with ERCOT that would not otherwise be operated except that they are necessary to provide voltage support, stability or management of localized transmission constraints under first contingency criteria where Market Solutions do not exist.

ERCOT STUDY• Includes

– Security Operations– Transmission Services

• Existing (history) and possible future conditions included in review

• Category A & B contingencies in the ERCOT Planning Criteria

• 100% of RATEB thermal limits• Voltage limits

– Voltage 0.90 PU to 1.05 PU– Nuclear units license requirements

• Sensitivity (priority) of units • Load shedding option with sensitivity

Reliability Must Run (RMR) UnitsResource Entity Unit MWFrontera Generation L.P. Frontera Power Station Unit 1 150West Texas Utilities Fort Phantom Unit 2 202West Texas Utilities San Angelo Unit 1 21West Texas Utilities San Angelo Unit 2 102West Texas Utilities Rio Pecos Unit 6 98Central Power and Light J. L. Bates Unit 1 74Central Power and Light J. L. Bates Unit 2 109Central Power and Light B. M. Davis Unit 1 335Central Power and Light B. M. Davis Unit 2 356Central Power and Light La Palma Unit 4 23Central Power and Light La Palma Unit 5 23Central Power and Light La Palma Unit 6 153Central Power and Light La Palma Unit 7 50Central Power and Light Laredo Unit 1 35Central Power and Light Laredo Unit 2 32Central Power and Light Laredo Unit 3 105

Fort Phantom Unit 2 (1977)• PROBLEM

– Autotransformer Loading– Line Loading

• SHORT TERM SOLUTION– None

• LONG TERM SOLUTION– Loop Sweetwater Cogen to Graham 345 kV line into Fort

Phantom– Create New 345/138 kV Switch Station– Time frame 2 to 3 years, assuming no problems with line

Fort Phantom Unit 22003 Modified Summer Peak Base Case Flows

Paint Creek and Oak Creek off line

Fort PhantomOff line

Contingency OutageMulberry Creek Auto

MVA Limit Contour

San Angelo Units 1 & 2 (1965 & 1966)

• PROBLEM– Voltage Control/Collapse

• SHORT TERM SOLUTION– Completion of Morgan Creek-Twin Buttes-Red Creek-

Comanche Sw 345 kV line– Installation of Twin Buttes 345/138 kV autotransformer– Projects started December 1998– Complete by June, 2003

• LONG TERM SOLUTION– Install static and dynamic reactive resources to

control/support voltage under normal, light load and contingency conditions

San Angelo Units 1&2 Modified Summer 2002 Base Case Powerflow

N-1 Voltage Contour

San Angelo PlantOff Line

Contingency OutageRed Creek 345 KV

Voltage Contour

Rio Pecos Unit 6 (1969)• PROBLEM

– Voltage Control McCamy Area

• SHORT TERM SOLUTION– Install shunt reactive at Rio Pecos– In-Service Date April 2003

• LONG TERM SOLUTION– Install static and dynamic reactive resources to

control/support voltage under normal, light load and contingency conditions

– Remove waiver of reactive requirements for wind generators (can now be done with small SVC’s)

Rio PecosLow Load (30,000 MW)

High Wind (75% Cap Factor)

Rio Pecos Off Line

Rio Pecos

BM Davis Unit 1 & 2 (1974, 1976)

• PROBLEM– Voltage Control/Support– Line Loading (several contingencies & limiting elements)

• SHORT TERM SOLUTION– Install static and dynamic reactive resources to

control/support voltage under normal and contingency conditions

– Continue upgrade of 138 kV system

• LONG TERM SOLUTION– Loop Lon Hill to Rio Hondo 345 kV line into South Side of

Corpus Christi– Create New 345/138 kV Switch Station– Time frame 3 to 4 years, assuming no problems with line

B. M. Davis Units 1&2 N-1 (cross channel cable) Summer 2003 Base Case Flow

Oxygen531 MW

Gregory470 MW

CCEC0 MW

L Hill0 MW

Contingency OutageWhite Point – Nueces Bay cable 138 Kv

B DavisOff line

MVA Limit Contour

Oxygen531 MW

Gregory470 MW

CCEC0 MW

L Hill0 MW

B DavisOff line

Contingency OutageHwy 9 - CCEC 138 Kv

B. M. Davis Units 1&2 N-1 (Hwy 9 - CCEC) Summer 2003 Base Case Flow

MVA Limit Contour

J L Bates Unit 1 & 2 (1958, 1960)Frontera Unit 1 (1999)

• PROBLEM– Extreme line loading (many contingencies and limiting

elements)• SHORT TERM SOLUTION

– Continue upgrade of 138 kV system– Immediate reconductor of Edinburg-McColl Rd 138 kV line with

high temperature conductor– Complete by April 2003

• LONG TERM SOLUTION– Install static and dynamic reactive resources to control/support

voltage under normal and contingency conditions– Construct Edinburgh-Bates-South McAllen 345 kV line– Install two 345/138 kV switch stations at Bates and South

McAllen– Construct 345 kV line from South McAllen to Lomo Alto to

LaPalma– Install 345/138 kV autotransformer at Lomo Alto– Time frame 3 to 6 years, assuming no problems with lines

On Peak - Bates Bates 0 MW

Frontera dispatched at Max. Cap.Load = 57,000 MWCurrent line ratings used

ContingencyMV Pharr – Pharr 138

MVA Limit Contour

On Peak - Frontera Unit 1 Frontera 0 MW

Bates dispatched at Max. Cap.Load = 57,000 MWCurrent line ratings used

ContingencyMV Pharr – Pharr 138

MVA Limit Contour

La Palma Unit 4,5,6,&7 (1947,1949,1970,1975)

• PROBLEM– Line loading (many contingencies and limiting elements)

• SHORT TERM SOLUTION– Continue upgrade of 138 kV system

• LONG TERM SOLUTION– Install static and dynamic reactive resources to control/support

voltage under normal and contingency conditions– Construct Edinburgh-Bates-South McAllen 345 kV line– Install two 345/138 kV switch stations at Bates and South

McAllen– Construct 345 kV line from South McAllen to Lomo Alto to

LaPalma– Install 345/138 kV autotransformer at Lomo Alto– Time frame 3 to 6 years, assuming no problems with lines

On Peak - La Palma Units 4-7La Palma Gen = 0 MW

ContingencyRio Hondo – La Palma 345

2003 Summer Peak DispatchLoad = 57,000MWCurrent line ratings used

MVA Limit Contour

Laredo Unit 1,2&3 (1951, 1955, 1975)

• PROBLEM– Line loading– Voltage control/support

• SHORT TERM SOLUTION– Install static and dynamic reactive resources to

control/support voltage under normal and contingency conditions

– Already in-service, does not solve line loading

• LONG TERM SOLUTION– Construct San Miguel-Laredo-Bates 345 kV line

• May need series compensation– Install two 345/138 kV switch stations around Laredo– Time frame 4 to 8 years, assuming no problems with

lines

Laredo Units 1-3Modified N-1 2003 Summer Base Case Flow

Contingency OutageRed Creek 345 KV

System Load at 57,000 MWLaredo at 25 MW

MVA Limit Contour

Laredo Units 1-3Modified 2003 Summer Base Case Flow

Voltage Contour

Load = 57,000MWNo Laredo STATCOMNo Laredo Capacitor Banks

Laredo UnitsOff line

TRANSMISSION RESOURCES

• ARE NOT INFINITE– Capital Limitations– Planning Limitations– Construction Limitations

• FOCUSING RESOURCES ON RMR WILL DIVERT IT AWAY FROM OTHER PROJECTS

• PRIORITIZATION CRITERIA NEEDED– Reliability Needs (serving load)– Congestion Needs– RMR Needs– Generation Interconnection Needs