Windmill power systems controller design using H∞ theory

In this paper, a mixed sensitivity weighting strategy for H^∞ controller design for an induction generator/infinity bus windmill power system is presented. The approach is based on a form of quasi-linearization which makes the windmill power system a linear function of the control input. The system controller is then synthesized by using H^∞ standard controller design techniques. A combination of additive and multiplicative uncertainty representation is used to achieve the robust stability for a wide range of operating conditions. The capability of the proposed controller to damp out the oscillations of the power and angular velocity, and the robustness with respect to the system parameter variations and model errors are evaluated in the simulation study