Robust Adaptive Fault Tolerant Pitch Control of Wind Turbines

Inaccuracy in linear modeling of wind turbines, effects of wind speed disturbance, and faults in components of the closedloop system increase the need for advanced controllers in wind energy conversion systems. In this article, an adaptive pitch controller is developed to regulate the generator speed in region 3. Also, an adaptive feed-forward term is augmented to improve the generator speed regulation in presence of the wind speed disturbance. Parameters of the controller are adaptively adjusted based on the improved dead-zone modification rule that guarantees closed-loop stability and zero regulation error in presence of the unstructured modeling uncertainties, step-like wind speed disturbance, and faults in pitch actuator. Proposed controller is compared to the baseline proportional-integral controller for controls advanced research turbine. Simulation results confirm the improvement in closed-loop regulation performance with proposed robust adaptive controller.