Switching LPV Controllers for a Variable Speed Pitch Regulated Wind Turbine

This paper deals with the control of a variable speed, pitch regulated wind turbine in the whole plant operating area. The wind turbine operating area can be divided into several zones, depending on the wind speed, and the control objectives are different for each operating zone. An hybrid control system composed by several LPV controllers which switches during transitions from one operating area to another is designed in order to ensure asymptotic stability and a good level of performances in the whole operating area. The LPV controllers are calculated from a convex LMI formulation of the problem in order to minimize an H2=H¥ criteria that optimizes the energy conversion of the system and that reduces the mechanical fatigue of the plant mechanical structure. The proposed controller is finally compared with two more conventional ones.