Rapid optimization of stall-regulated wind turbine blades using a frequency-domain method: Part 2, cost function selection and results
Article first published online: 28 MAR 2014
Copyright © 2014 John Wiley & Sons, Ltd.
How to Cite
Merz, K. O. (2014), Rapid optimization of stall-regulated wind turbine blades using a frequency-domain method: Part 2, cost function selection and results. Wind Energ.. doi: 10.1002/we.1738
- Article first published online: 28 MAR 2014
- Manuscript Accepted: 13 FEB 2014
- Manuscript Revised: 5 SEP 2013
- Manuscript Received: 13 DEC 2012
- stall regulated;
- blade design;
- frequency domain
A fast and effective frequency-domain optimization method was developed for stall-regulated blades. It was found that when using linearized dynamics, typical cost functions employing damage-equivalent root bending moments are not suitable for stall-regulated wind turbines: when the cost function is minimized, the edgewise damping can be low, and the flapwise damping can approach zero during an extreme operating gust. A new cost function is proposed that leads to nicely balanced stall behavior and damping over the entire operating windspeed range. The method was used to design the blades of two multi-MW, stall-regulated, offshore wind turbines, comparable with the NREL 5 MW and NTNU 10 MW pitch-regulated turbines. It is shown that the optimal stall-regulated blade has a unique aerodynamic profile that gives high flapwise and edgewise damping and a uniform mean power output above the rated windspeed. The blades are described in sufficient detail that they can be used in further aeroelastic analyses, to compare large stall-regulated and pitch-regulated turbines. Copyright © 2014 John Wiley & Sons, Ltd.