WINDSCANNER.DK:

LIDAR WIND SPEED MEASUREMENTS FROM A ROTATING SPINNER

T. Mikkelsen, K. Hansen, N. Angelou, M. Sjöholm, M. Harris, P. Hadley, R. Scullion, G. Ellis, G. Vives

Risø DTU, Roskilde, Denmark Natural Power, Malvern, UK

2 Risø DTU, Technical University of Denmark

WindScanner.dkFrom new Wind Lidar Technologytowards new Wind EnergyResearch Infrastructures…:

Technical focus

Scientific focus

RI focus

Current Status

EU ESFRIRoad Map

2010 ?

First CW Wind lidar 2004

MusketeerEX 2007/2008

SpinnerEX 2009

WindScanner.dk2010-2013

3 Risø DTU, Technical University of Denmark

WindScanner.dk methodology is based on 3-dimensional scanning with wind lidar's to determine the instantaneous turbulence fields:

Since 2005 new wind lidar's have enabled replacement of tall (80-300 m) MET masts

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Ø

HH

• 25 kW Wind Turbine 1975:• Ø/H ~ 0.3

• 2.3 MW NM80• Height 59 m;• Ø=80H• <Ø/H ~ 1.4

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Spinner Integrated Lidar I: Experimental Setup:Pro-active wind turbine control from upwind measurements by lidars

integrated in the rotating Spinner… :

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Tjæreborg SPINNER-EX

2009Spinner – mounted

lidar

CW Lidar: ZephIR (50 Hz)

Wind Turbine: NM80(NegMicon/Vestas)

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Tjæreborg: ZephIR “Spinner-Ex.” …:

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Real-time LIDAR Raw data (50 Hz un-calibrated):

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Time series (10 s) of approaching wind conditions measured +100 m upwind:

Ex.: Inhomogeneous wind field

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Spinner Integrated Lidar II: Measurements and ResultsPro-active wind turbine control from upwind measurements by lidar's

integrated in the rotating Spinner… :

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Measurement Setup’s:

Period Wedge DistanceApril – May 2009 15o ~1.24ØJuly – August 2009 30o ~0.58Ø

Wind speed values per rotation (each frame contains 10 consecutive

scanning circles)

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The loci of the focussed lidar beamRadial wind speeds during a 10-min sampling period

Upwind @ 1.24 Ø (+ 100 m):

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Geometry

Radial Wind Speeds –Wind Turbine-referenced:

Horizontal Wind Speeds –ground-referenced:

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Results

Correlation between lidar and mast

Study of the approaching wind field

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Wind turbine Yaw-misalignment relative to time-averaged wind direction as measured by lidar:

0 2000 4000 6000 8000 30 20 10010203040

Tim e s wDegrees 1 0m in

5m in3m in2m in1m in3 0 s e c

Yaw misalignment angles at hub height (57m)

01:10 01:30 01:50 02:10 02:30 02:50 03:10 03:300

10

20

30

40

50

Tim e HH :MM Direction

Degrees W TY AWSo n ic 5 7 m

Dire

ctio

n [d

egre

es]

Time [HH:MM]

Time [sec]

Θ w [d

egre

es]

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0 2 4 6 8 100

100

200

300

400

500

600

700

u m sPo

werkW

0 2 4 6 8 100

100

200

300

400

500

600

700

u m s

PowerkW

0 2 4 6 8 100

100

200

300

400

500

600

700

u m s

PowerkW

0 2 4 6 8 100

100

200

300

400

500

600

700

u m sPo

werkW

0 2 4 6 8 100

100

200

300

400

500

600

700

u m s

PowerkW

0 2 4 6 8 100

100

200

300

400

500

600

700

u m s

PowerkW

10-min averages

Power curve measurements based on Spinner Lidar data:

Power curves from lidar wind speed 100 m (1.24 Ø) upwind

Power curves based on hub-height cup anemometer

1-min averages 1-s averages

Powe

r [kW

]Po

wer [

kW]

U [m/s] U [m/s] U [m/s]

U [m/s]

U [m/s]

U [m/s] U [m/s]

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Spinner Integrated Lidar III: Future Work 2D Rotor Plane Scans Pro-active wind turbine control from upwind measurements by lidars

integrated in the rotating Spinner… :

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Scanning in 2-D:

”Risley prism”

Dual-prism single-axis beam steering:

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Scope for further wind LIDAR integration:

Rotor Plane Upwind

Blade integrated

lidar

Spinner integrated

lidar

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Future research and applications:

1. More precise yaw alignment using lidar2. Proactive (typically +10 s) Pitch control3. Pro-active RPM control4. Warning and mitigating of extreme loads (from gusts)5. More percise power-curve measurememts6. …

Acknowledgements:The Tjæreborg “Lidar-in-spinner Experiment” was conducted as part of the Windscanner.dk RI activities 2009.Meteorology and turbine data have been provided via the Danish DAN-AERO MW project.Access to the NM80 research Turbine was granted by Vestas and Dong Energy.