Validation of a Second Generation Type 3 Generic Wind Model

Matthew P. Richwine (Presenter) matthew.richwine@ge.com

Juan J. Sanchez-Gasca Nicholas W. Miller

July 30th, 2014 IEEE PES GM

Washington DC

1

Introduction

• GE in active in development of dynamic models

• Use for modeling dynamics of the bulk power system

• Always evolving, trade-offs

2

Converter

Control

Model

Pitch

Control

Model

Wind

Turbine

Model

Blade Pitch

Generator /

Converter

Model

Power

Order

Speed

OrderShaft Speed

Current Command, Ip

Voltage Command, Eq

Real

Power

Terminal Voltage

Regulated Bus Voltage

Real & Reactive

Power

Pgen

Qgen

First-Generation Type 3 Generic Model GE Type 3 Wind Turbine Model

Motivation for Testing

Represent installed behavior

Validation checks that models are reasonable

Highlights areas where models can be improved

Emerging Requirements ie. NERC MOD-025,-026,-027

3

Wind Turbine Model

Generic Models v. GE Models

- Both models are similar in that they neglect the generator flux

- GE models differ in the following ways:

- Voltage Droop

- Active Power Control (APC)

- WindINERTIA

- LVRT, ZVRT

4

Torque

Control

Pitch

ControlAero

Drive-Train

Electrical

Control

Generator/

Converter

Pgen

Pgen

Prefo

Qref

Pord

Pref

w

w ref

Iqcmd

Ipcmd

Iq

Ip

Plant Level

Control

Vref/Vreg

or Qref/Qgen

fref/freq and

Plant_pref/Pgen

Vterm

Pgen

Qgen

Pm

q

Changes from first generation to second generation

- Modularity (7 modules v. 4 modules)

- More input to model development

Converter

Control

Model

Pitch

Control

Model

Wind

Turbine

Model

Blade Pitch

Generator /

Converter

Model

Power

Order

Speed

OrderShaft Speed

Current Command, Ip

Voltage Command, Eq

Real

Power

Terminal Voltage

Regulated Bus Voltage

Real & Reactive

Power

Pgen

Qgen

First-Generation Generic Model

Second-Generation Generic Model

Model Validation Approach Equipment

Representation

Model Validation Actual Equipment

Medium Voltage Bus (e.g. 34.5kV) Terminal Bus

P gen

Q gen

Vreg bus

Vterm

Unit Transformer

Point of Interconnection

(POI) Bus

Substation

Transformer

Collector Equivalent Impedance

Unit transformers are typically 2-3 MVA, 6% leakage reactance delta-wye connected padmounts, modeled as a single equivalent transformer

Multiple wind turbines are modeled as a single equivalent wind turbine

The collector system may cover several miles, have different topologies, and is modeled as an equivalent impedance.

Substation transformers usually have FOA rating roughly equal to total MVA of WTGs. Switching shunt reactive compensation at the substation may be used as a stimulus for testing

Wind Plant Model

System Model

Physical Wind Farm Schematic

7

Equivalent Wind Farm Schematic

Voltage Reference Step Test

Testing can be challenging

• Changing wind conditions

• Changing grid conditions

Voltage Reference Step Test

• Voltage regulation mode

• +2% step at POI (144kV bus)

• Near unit PF prior to step

• Power fluctuating with wind

8

Capacitor Bank Switching Test

Shunt Capacitor Switching Test

• Voltage regulation mode

• 10MVAr capacitor switched in, then out

• Near unit PF at the start of testing

• Power (wind speed) decreasing

9

Future Work • Capturing power fluctuations in simulation

• Frequency response testing

• Multi-plant volt/Var coordination

10

Active coordination

regulates POR

voltage (Red)

Active coordination

balances VARs

from all wind farms

Shunt Capacitor Opens with Active Coordination

applied on top of Droop Coordination

WF1 WF2 WF3

System

Shunt Cap

POR Bus

Conclusions

• Staged testing shows a match among Generic models, GE models, field test results

• Reactive power path is decoupled from the active power path

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References

[1] A. Ellis, E. Muljadi, J. Sanchez-Gasca, Y. Kazachkov, “Generic Models for Simulation of Wind Power Plants in Bulk System Planning Studies”, Proc. IEEE Power Engineering Society General Meeting 2011, Detroit, MI, USA, July 24-28.

[2] A. Ellis, Y. Kazachkov, E. Muljadi, P. Pourbeik, J.J. Sanchez-Gasca , Working Group Joint Report – WECC Working Group on Dynamic Performance of Wind Power Generation & IEEE Working Group on Dynamic Performance of Wind Power Generation of the IEEE PES Power Stability Controls Subcommittee of the IEEE PES Power System Dynamic Performance Committee, “Description and Technical Specifications for Generic WTG Models – A Status Report”, Proc. IEEE PES 2011 Power Systems Conference and Exposition (PSCE), March, 2011, Phoenix, AZ.

[3] P. Pourbeik, A. Ellis, J. Sanchez-Gasca, Y. Kazachkov, E. Muljadi, J. Senthil and D. Davies, “Generic Stability Models for Type 3 & 4 Wind Turbine Generators for WECC”, Proc. IEEE Power Engineering Society General Meeting 2013, Vancouver, British Columbia, Canada. July 2013.

[4] T. Ackermann, A. Ellis, J. Fortmann, J. Matevosyan, E. Muljadi, R. Piwko, P. Pourbeik, E. Quitmann, P. Sorensen, H. Urdal, B. Zavadil, “Code Shift – Grid Specifications and Dynamic Wind Turbine Models”, IEEE Power and Energy, vol. 11, pp. 73-82, Nov./Dec. 2013

[5] E. Muljadi, C.P. Butterfield, A. Ellis, J. Mechenbier, J. Hocheimer, R. Young, N. Miller, R. Delmerico, R. Zavadil, J.C. Smith, ”Equivalencing the Collector System of a Large Wind Power Plant”, presented at the IEEE Power Engineering Society, Annual Conference, Montreal, Quebec, June 12-16, 2006.

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