ERCOT Staff Facilitator

Juan S. Santos

Senior Consultant, System Planning Technical Operations

jsantos@ercot.com

WIND GENERATION STABILITY MODELING TASK FORCE

UPDATE FOR ROS

APRIL 9, 2002

MOTIVATION

• Large number of new wind plants in West Texas•1000+ MW & Growing

•West Texas already is transmission limited•Primary is stability limit•Secondary is thermal limits

•Accurate and Appropriate models development is necessary to support transmission planning and operational studies.

•Model development does have a cost•Share the costs

•More Wind Generation Development is likely !

GENERATOR OUTPUT AND WIND SPEED

TYPES OF STABILITY STUDIES

Small Signal Stability

Power System Stability

Angle Stability Frequency Stability Voltage Stability

Transient StabilityLarge DisturbanceVoltage Stability

Small DisturbanceVoltage Stability

Short Term Short TermLong Term Long Term

Small Signal StabilitySmall Signal

Stability

Power System StabilityPower System Stability

Angle StabilityAngle Stability Frequency StabilityFrequency Stability Voltage StabilityVoltage Stability

Transient StabilityTransient StabilityLarge DisturbanceVoltage Stability

Large DisturbanceVoltage Stability

Small DisturbanceVoltage Stability

Small DisturbanceVoltage Stability

Short TermShort Term Short TermShort TermLong TermLong Term Long TermLong Term

MODELING REQUIREMENTS

• Control Block Diagrams• Transmission interconnection point “aggregated”

wind farm model.• Incorporated in the PTI PSSE program and model

library.– For use by ERCOT Staff, TSP’s & Stakeholders

• Validation that the numerical model responds the same as the “real world”.– Monitoring & Testing

• Flexible Model with ability to incorporate “local” time and seasonal factors– Stochastic Nature of Wind

• Account for both Real and Reactive power under steady state and dynamic studies

• Translation into PTI – Source Code

ADDITIONAL MODELING REQUIREMENTS

• Electro-mechanical interaction between turbines in “wind farms” that are near and with different set points excited by disturbances in power grid?– Soft shafts and different control set

points•pitch control, variable speed, voltage

control etc…

• Effects of weak system (low X/R ratio)• Periodic pulsations due to wind shear,

wind speed and turbulence • Model voltage, transient and

subtransient stability phenomenon

COST SHARINGInvoices Sent Out 02/26/02

COMPANY SITE NAMESIZE (MW)

% OF COST

RECD

Cielo Wind Capital Hill 100 8.9%

Trent Wind Farm, LP Trent Wind Farm 150 13.3%

Indian Mesa Power Partners LP Enron Indian Mesa I & II 160 14.2%

FPL Energy Pecos Wind Woodward Mt. Wind Ranch 160 14.2%

FPL Energy Upton Wind I King Mt. Wind Ranch 79.3 7.0%

FPL Energy Upton Wind II King Mt. Wind Ranch 79.3 7.0%

FPL Energy Upton Wind III King Mt. Wind Ranch 79.3 7.0%

FPL Energy Upton Wind IV King Mt. Wind Ranch 40.3 3.6%

NWP Indian Mesa Wind Farm, LP

Indian Mesa Wind Farm 82.5 7.3%

AEP-WTU Fort Davis 1 6 0.5%

FPL Energy Mesa Wind 1 (SW Mesa) 74.6 6.6%

Delaware Mountain Wind Farm, LP

Delaware Mountain Wind Farm 1

30 2.7%

New World Texas Renewable Energy

Big Spring Wind power Facility& Westex I Wind power

40.92 3.6%

Wind Power Partners, LP Kunitz 1 44.8 4.0%

VERY ROUGH COST ESTIMATE

– Model Development $125,000 to $200,000– Travel/Meetings $10, 000 to $20,000– Validation /Testing $50,000 to $80,000 (?)– Data Research $20,000 to $30,000 (?)– Monitoring Equipment $20,000 to

$30,000 (?)– Totals estimated at $225,000 to $360,000

DRAFT TIME TABLE M J J A S O N D J F M A M

Funding

XX XX

Contractor Starts

XX XX XX XX

Mid-point

XX XX

Completion

XX XX XX XX

Ready to use in PTI

PSSE XX XX

Install equipment

XX XX XX

Collecting Data

XX XX XX XX XX XX XX XX

Tuning

XX XX