Title: Multimodel LQ controller design for variable-speed and variable pitch wind turbines at high wind speeds

Authors: Nadhira Khezami; Xavier Guillaud; Naceur Benhadj Braiek

Addresses: LECAP, École Polytechnique de Tunisie, BP 743 – 2078 La Marsa, Tunisie. ' L2EP, École Centrale de Lille, Cité Scientifique, 59651 Villeneuve d'Ascq Cedex, France. ' LECAP, École Polytechnique de Tunisie, BP 743 – 2078 La Marsa, Tunisie

Abstract: This paper focuses on designing a multimodel linear quadratic (LQ) controller for variable-speed horizontal axis wind turbines. Those turbines use blade-pitch and electromagnetic torque control to meet specified objectives for three regions of operation. We aim in this paper to use the blade-pitch control in the high wind speed operating zone. The controller is then designed in order to optimise a trade-off between two main control objectives which are alleviation of drive train dynamic loads and maximisation of energy efficiency. It is thereafter implemented for a deloaded operation to provide an additional operating reserve necessary to increase the effective participation of the wind turbines in the system frequency regulation. A 2MW wind turbine is considered to illustrate the good performances brought by the proposed approach by presenting and discussing the simulation results.

Keywords: variable speed wind turbines; high wind speed operating zone; LQ controllers; multimodelling; deloaded operation; modelling; wind energy; wind power; linear quadratic control; horizontal axis wind turbines; blade-pitch control; controller design; simulation.

DOI: 10.1504/IJMIC.2012.045217

International Journal of Modelling, Identification and Control, 2012 Vol.15 No.2, pp.117 - 124

Published online: 29 Nov 2014 *

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