Improved drive-train and blade fatigue mitigation in flexible wind turbines using disturbance utilization control

Modern wind turbines are experiencing rapid growth in both physical size and rated capacity. As wind turbines grow larger with necessarily lighter construction materials, dampening flexible modes with active control becomes more critical. In this paper we apply the theory of ldquodisturbance utilization controlrdquo (DUC) to a 600 kW upwind machine to dampen drive-train torsion and blade flap while regulating generator speed. We show that positive ldquoutilityrdquo exists in turbulent wind inflow, and we demonstrate that the optimal DUC controller achieves decreased pitch actuator demand and improved drive-train and blade fatigue life through dampening of torsion oscillation and blade flap.