On the optimal tuning of individual pitch control for horizontal-axis wind turbines

Abstract

Individual pitch control has proved capable of reducing loads on the blades and shaft of a horizontal-axis wind turbine, at the price of a potentially substantial increase in actuator activity. With accurate tuning of the control parameters, the overall performance can be satisfactorily balanced, but a manual tuning procedure often proves unbearably costly and the solution found may be far from optimal. This study tries to explore the feasibility of an optimal approach to the problem of tuning of individual pitch control, by mapping reasonable cost functions with respect to some parameters of interest in control design. The analysis is carried out by considering a possible individual pitch control implementation, tested in a virtual environment on a realistic testbed. The merit functions are also analyzed visually, in order to easily understand the effects of the various design parameters on the positions and quality of the respective optima. In a later stage, results of complete optimization runs are presented, and the approach is critically discussed.