Nonlinear Control and Observation of a PMSG Wind Turbine Through Unknown Wind Torque Characteristics

Increased global demand for renewable energy production makes wind power capture an attractive option. This paper proposes a nonlinear backstepping controller for a full-variable wind turbine incorporating a permanent magnet synchronous generator. This control strategy manages the tip speed ratio via the rotor speed to achieve maximum power capture without knowledge of the wind torque characteristics. If these torque characteristics are required, a nonlinear observer is also presented, which can dynamically learn the wind torque. The proposed controller and observer schemes are validated through Lyapunov-based stability analyses and simulation results are shown which demonstrate the controller and observer viability.