wind turbine control design to reduce capital costs p. jeff darrow(colorado school of mines) alan...

WIND TURBINE CONTROL DESIGN TO REDUCE CAPITAL COSTS

P. Jeff Darrow (Colorado School of Mines)Alan Wright (National Renewable Energy Laboratory)Kathryn E. Johnson (Colorado School of Mines)

Overview Introduction Wind Turbine Description Baseline Controller Description Design Load Cases (DLCs) Preliminary Results Conclusions Future Work

Introduction - Work Site(s) This research in this project is being

performed at two sites The National Wind Technology Center

(NREL) Colorado School of Mines

Introduction - Motivation Increasing demand for wind energy

Wind turbines operate in extreme conditions Experiencing both fatigue and extreme loads

IEC dictates a minimum design life of 20 years

The current design approach is to use robust components

This causes a high capital cost of each wind turbine

Introduction – Goals Perform a full loads case analysis

Help guide wind turbine control research Identify design driving events and the

responsible factors Develop advanced control techniques to

mitigate prominent loads

Show a potential to reduce capital costs with controller design

Introduction - General This research is still in progress

Results are specific to the CART3

Controls Advanced Research Turbine

Wind Turbine Description

Regions of Operation

Controls Advanced Research Turbines The NWTC has two primary research turbines Model: Westinghouse WTG-600 Originally from a wind farm in Oahu, Hawaii However, they are not ordinary (industry)

turbines Specially outfitted with extra sensors and

actuators for research purposes Original pitch system replaced New generator system added New control system added

Control Actuators Blade pitch

Limit of 18˚/second

Generator torque Limit of 3581 N*m

Yaw Limit of 0.5 ˚/second

CART3 Characteristics 3 bladed, upwind Active yaw Rated power: ~600 kW Rated torque: 3581 N*m Class IIB rating by IEC Rated wind speed: 13.5 m/s Rated rotor speed: 41.7

rpm Cp,max: 0.4666

CART3 Model for Simulations

Three main components Rotor Tower Nacelle

Modeled with the NREL design-code FAST Uses many DOF’s to

model turbine dynamics

1st & 2nd Blade Flap Mode

1st & 2nd Tower Fore-Aft Mode

1st & 2nd Tower Side-toSide Mode

1st Blade Edge Mode

Nacelle Yaw

Generator Azimuth

Shaft Torsion

Platform Yaw

Platform Roll

Platform Pitch

Platform Heave

Platform Sway

Platform Surge

CART Model - DOFs

1st TowerSide-to-Side ModeShaft

Torsion

1st TowerFore-Aft Mode

• Design• Implementation• Verification

Baseline Controller Description

Baseline Controller Design Baseline controller works in regions 2,

2.5, and 3 Region 2 uses torque control: Regions 2.5 provides a linear torque

curve Region 3 uses a PID type collective pitch

controller

2 k

Baseline Controller Implementation The fore mentioned control scheme is

implemented using a DLL linked to the FAST model

Region 2 control is built into the FAST simulator

Region 3 control is defined in the linked DLL

Operation of overall controller was verified for proper operation

Baseline Controller Verification

Design Load Cases

Design Load Cases (DLC’s) Defined by IEC Document 61400-1

Provides load cases to predict turbine loading

Focus on cases that do not require controller logic for start-up/shutdown

Each applicable case applied to the CART3 model Resulting loads observed

DLCs of InterestDLC Winds Controls/Events

Model Speed1) Power Production1.1 NTM Vin < Vhub < Vout Normal Operation1.3 ETM Vin < Vhub < Vout Normal Operation

1.4 ECD Vhub = Vr, Vr ±2m/s Normal Operation: ±Δ Wind Direction

1.5 EWS Vin < Vhub < Vout Normal Operation: ±Δ Vert & Horz Shear1.6 NTM Vin < Vhub < Vout Normal Operation2) Power Production w/ Occurance of Fault

2.1 NTM Vhub = Vr, Vout Pitch Runaway Shutdown2.3 EOG Vhub = Vr, Vr ±2m/s, Vout Loss of Load Shutdown6) Parked6.1a EWM Vhub = 0.95*V50 Yaw = 0°, ±8°

6.2a EWM Vhub = 0.95*V50 Loss of Grid ; -180° < Yaw <180°6.3a EWM Vhub = 0.95*V1 Yaw misalignment of +30°7) Parked w/ Occurance of Fault7.1a EWM Vhub = 0.95*V1 Seized Blade; Yaw = 0°, 8°

Only a representative subset of the total available results is presented

here

Preliminary Results

DLC 1.3 -- Power Production-- Extreme Turbulence Model-- No faults

0 100 200 300 400 500 6006

7

8

9

10

11

12

13

14

15

16

Time (sec)

Win

dVxi

(m/se

c)

Time Series Plots of Wind Speed


0 100 200 300 400 500 600

200

400

600

Time (sec)

Root

Myb1

(kN·

m)

0 100 200 300 400 500 600

-100

0

100

200

Time (sec)

Root

Mxb1

(kN·

m)

Time Series Plots of Blade 1 Moments


0 100 200 300 400 500 600

60

80

100

120

140

160

Time (sec)

LSSh

ftTq

(kN·

m)

Time Series Plots of Shaft Torque


0 100 200 300 400 500 6000

200400

Time (sec)TwHt

1MLx

t (kN

·m)

0 100 200 300 400 500 6002000250030003500

Time (sec)TwHt

1MLy

t (kN

·m)

0 100 200 300 400 500 600-2000

200400

Time (sec)TwrB

sMxt

(kN·

m)

Time Series Plots of Tower Moments

DLC 2.3 -- Power Production-- Extreme Operating Gust-- Internal Electrical System Fault

30 40 50 60 70 80 9010

11

12

13

14

15

Time (sec)

Win

dVxi

(m/se

c)

Time Series Plots of Wind Speed


30 40 50 60 70 80 90

300350400450

Time (sec)

Root

Myb1

(kN·

m)

30 40 50 60 70 80 90-100

0

100

Time (sec)

Root

Mxb1

(kN·

m)



30 40 50 60 70 80 900

20

40

60

80

100

120

140

160

Time (sec)

LSSh

ftTq

(kN·

m)



30 40 50 60 70 80 900

200400

Time (sec)TwHt

1MLx

t (kN

·m)

30 40 50 60 70 80 900

100020003000

Time (sec)TwHt

1MLy

t (kN

·m)

30 40 50 60 70 80 900

200400600

Time (sec)TwrB

sMxt

(kN·

m)


DLC 6.3 -- Parked-- Extreme Wind Model-- 30° Yaw misalignment

0 100 200 300 400 500 6006

7

8

9

10

11

12

13

14

15

Time (sec)

Win

dVxi

(m/se

c)Time Series Plots of Wind Speed


0 100 200 300 400 500 600

3040506070

Time (sec)

Root

Myb1

(kN·

m)

0 100 200 300 400 500 600-5

0

5

10

Time (sec)

Root

Mxb1

(kN·

m)



0 100 200 300 400 500 600

0

5

10

15

20

25

30

35

Time (sec)

LSSh

ftTq

(kN·

m)



0 100 200 300 400 500 6000

200400600

Time (sec)TwHt

1MLx

t (kN

·m)

0 100 200 300 400 500 600400600800

10001200

Time (sec)TwHt

1MLy

t (kN

·m)

0 100 200 300 400 500 6000

200400600

Time (sec)TwrB

sMxt

(kN·

m)


Conclusions & Future Work

Conclusions The CART3 had been successfully modeled

in FAST

The baseline controller has been developed and implemented in simulation

All DLCs of interest have been simulated

We currently have all of the data needed to conduct an in depth analysis

Future Work Continue work to quantify design driving

events

Design and simulate controllers to handle prominent cases

Re-run the suite of DLCs to show new results

We hope to show a potential to reduce the capital costs of a wind turbine by controller design

Acknowledgements Marshall Buhl

NREL Jason Jonkman

NREL

Have a wonderful day

Thank You

wind turbine control design to reduce capital costs p. jeff darrow(colorado school of mines) alan...

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