Self-scheduled H∞ Control of a Wind Turbine - A Real Time Implementation

This paper is concerned with the design of robust gain-scheduled controllers with guaranteed H∞ performance for a horizontal axis wind turbine (HAWT) with variable-speed and fixed-pitch. The control problem in terms of Linear Parameter-Varying (LPV) plants is stated and the theoretical background of the design method is given. Due to some interesting properties outlined in this paper, the synthesis problem is reduced to solving off-line a finite-dimensional set of Linear Matrix Inequalities (LMIs), making the controller suited for real-time applications. The computed LPV controller focuses on multiple objectives such as mechanical fatigue reduction, speed regulation and mode stabilization with simultaneously maximizing energy capture. The performances obtained through this control method are discussed and presented by means of a set of simulations. A real-time control algorithm for the large-scale wind turbines is also proposed.