ECN publication
Distributed Blade Control
Published by: Publication date:
ECN Wind Energy 21-10-2010
ECN report number: Document type:
ECN-M--10-073 Conference Paper
Number of pages: Full text:
17 Download PDF  

Presented at: The Science of Making Torque from Wind, Heraklion, Crete, Greece, 28-30 juni 2010.

Wind turbine designs are driven by aerodynamic loads on the structure. If loads are reduced, the dimensions of certain parts and the total cost can be reduced. Individual pitch control (IPC) is known to be effective, but a rotor with distributed blade control (DBC), also known as a smart rotor, can achieve more. With DBC the aerodynamic shape of the blade is adapted locally to reduce loads. Such a system can react quicker than IPC and can be tuned to local conditions.
This paper focusses on the combining different sensors with various control structures and shows what reductions in fatigue load can be obtained with DBC within realistic constraints. A rotor equipped with two control devices on each blade is examined. The resulting controllers are tuned to achieve performance within constraints and their stability is analysed. A linearised model of the Upwind 5MW reference turbine is used. The resulting damage equivalent loads are compared with those for baseline controller and IPC. This paper confirms that DBC is effective, reducing the damage equivalent loads by up to nearly 50% relative to the baseline controller. That is 18- 27% more reduction than IPC can achieve on its own. From the different sensor-controller combinations measuring the in-blade moments near the DBC actuators is found to be less useful than flapwise blade velocities or blade root moments. The best results are obtained when IPC and DBC are used together. The results show that it is also important to examine the effect on other turbine components.

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