Journal cover Journal topic
Wind Energy Science The interactive open-access journal of the European Academy of Wind Energy
Wind Energ. Sci., 1, 297-310, 2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research articles
01 Dec 2016
Articulated blade tip devices for load alleviation on wind turbines
Carlo L. Bottasso1,2, Alessandro Croce1, Federico Gualdoni1, Pierluigi Montinari1, and Carlo E. D. Riboldi1 1Wind Energy Institute, Technische Universität München, 85748 Garching b. München, Germany
2Dipartimento di Scienze e Tecnologie Aerospaziali, Politecnico di Milano, 20156 Milan, Italy
Abstract. This paper investigates the load alleviation capabilities of an articulated tip device, where the outermost portion of the blade can rotate with respect to the rest of the blade. Passive, semi-passive and active solutions are developed for the tip rotation. In the passive and semi-passive configurations tip pitching is mainly driven by aerodynamic loads, while for the active case the rotation is obtained with an actuator commanded by a feedback control law. Each configuration is analyzed and tested using a high-fidelity aeroservoelastic simulation environment, by considering standard operative conditions as well as fault situations. The potential benefits of the proposed blade tip concepts are discussed in terms of performance and robustness.

Citation: Bottasso, C. L., Croce, A., Gualdoni, F., Montinari, P., and Riboldi, C. E. D.: Articulated blade tip devices for load alleviation on wind turbines, Wind Energ. Sci., 1, 297-310,, 2016.
Publications Copernicus
Short summary
The paper discusses different concepts for reducing loads on wind turbines using movable blade tips. Passive and semi-passive tip solutions move freely in response to air load fluctuations, while in the active case an actuator drives the tip motion in response to load measurements. The various solutions are compared with a standard blade and with each other in terms of their ability to reduce both fatigue and extreme loads.
The paper discusses different concepts for reducing loads on wind turbines using movable blade...