energy innovation

More information:

E.L. van der HooftEnergy research Centreof the NetherlandsWind Energytel. +31 224 564913fax. +31 224 568214eml. vanderhooft@ecn.nl

Wind Turbine Control Algorithmsdevelopment for industrial useT.G. van Engelen, E.L. van der Hooft, P. Schaak

speed.

Research and development focuseson the prevailing turbine concept:

The multivariable wind turbine system isapproximated by different scalar subsystems:

well physically interpretable andindependently controllable.

variable speed, active pitch to vane.

APPROACH

Above rated wind speed, aerodynamicpower is controlled by

and both

effectuated by the Simultaneously, the electric

power is kept constant by control of thegenerator torque.

Narrow band feedback of tower topnodding and naying to the pitching

speed and generator torque enhancesthe damping rate of tower bending.

Feedback of the estimated shaftdeformation to the generator torque

lowers drive-train torsion resonance; a Kalman filter processes the measured

generator speed.

rotor speedfeedback feed forward of the

estimated windspeed,pitching

Pitch actuationsystem

Electric torqueservo

ω 3pco ω=Low pass filter

ω Vwco ω=Low pass filter

Electrictorque control

shaft torsiontorque control

Lateral towertorque control

ω dvtbp ω=Band pass filter

Σ

Σ

Σ

ω towbp ω=Band pass filter

Aerodynamictorque control

For/aft towerthrust controlω towbp ω=

Band pass filter

∆ddtΘ( )ref d

dtΘ( )act

refTegenTe

tower acceleration (fore/aft)

pitch angle

rotor speed

tower acceleration (lateral)

towTe

dvtTe

yieldTe

ddtΘ( )tow

ddtΘ( )aero

Wind turbine

rotor speedsetpoint

rotor speed

ddtΘ( )Te

= pitching speed

= electric torque

rotor speed regulation energy yield optimisation structural fatigue reduction

OBJECTIVES

high performance full load control atindustry-standard stability margins:- overall control loop assessment;- compensation for dynamic inflow;- in-loop wind speed estimator for fast reaction on wind gusts;- gain scheduling to cope with non linear aerodynamics;- rotor speed setpoint adaptation to utilise kinetic buffering;adaptive inactivity zone;forced rotor speed limitation inshort time extreme conditions;enhanced damping of towerbending and drive-train torsion;optimised partial load control;smooth transients between fulland partial load operation.

FEATURES AND PROPERTIES

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RESULTS

DELIVERABLES

C / FORTRAN-coded algorithmfor embedding in process computeror linking to aerodynamic code.

Time domain simulation of 3MW turbine

***

400 450 500 550 600 650

10

15

20

rotor effective wind speed (cyan); estimated windspeed (blue); rated wind speed (magenta)

[m/s

]

400 450 500 550 600 6501

2

3

4

5aerodynamic power (red); electric power (blue)

[MW

]

400 450 500 550 600 65010

12

14

16

18rotor speed (blue); rotor speed setpoint (red); rated rotor speed (magenta)

[rpm

]

400 450 500 550 600 6500

5

10

15

pitch angle (blue)

[dg]

400 450 500 550 600 650−4

−2

0

2

4pitching speed (blue)

[dg/

s]

time [s]