Active damping control of DFIG wind turbines during fault ride through

Grid voltage sag causes typical transients in the generator electromagnetic torque, which result in significant stress on the wind turbine drive-train. In this paper, a combination of different simulation packages, namely FAST (Fatigue, Aerodynamics, Structure, Turbulence) and Simulink, is used to model the mechanical and electrical aspects of a 5-MW doubly-fed induction generator (DFIG) based wind turbine respectively. To reduce the mechanical loads induced by grid faults, a linear-quadratic regulator (LQR) based generator torque controller is presented. Simulation results showed that the active damping controller can effectively suppress the vibration of drive-train during fault ride through (FRT).