Fixed-order ℋ∞ controller based on HIFOO for a Doubly-Fed Induction Generator wind turbine

The paper reports on the application of full-order ℋ∞ controller and ℋ∞ Fixed-Order Optimisation (HIFOO) controller to a Doubly-Fed Induction Generator wind turbine (DFIG). These controllers use the ℋ∞ mixed sensitivity problem to achieve an enhancement in both, Nominal Performance (NP) and Robust Stability (RS) margins for the uncertain DFIG plant while respecting constraints, such as dynamic tracking of the set-point references, load disturbances rejection and measurement noises attenuation. The simulation results show that with order reduction by half, the HIFOO controller presents effectiveness and efficiency with respect to the classical full-order ℋ∞ controller.