Power transition enhancement for variable-speed, variable-pitch wind turbines using model predictive control techniques

The wind turbine operating area can be divided into several regions, depending on wind speed. Transition from fixed speed to variable speed wind turbines has been a significant element in the Wind energy technology improvements. This has allowed adapting the turbine rotational speed to the wind speed variations with the aim of optimizing the aerodynamic efficiency. In this paper, a multivariable control strategy based on model predictive control (MPC) techniques for the control of variable-speed variable-pitch wind turbines is introduced. The main advantages of the proposed controller are that it is easily adaptable for different conditions in addition to its very fast response. The proposed control strategy is described for the two operating regions of the wind turbine, i.e. both partial and full load regimes. Pitch angle and generator torque are controlled simultaneously to maximize the captured energy and smooth the power generated while reducing the pitch actuator activity. Simulation results show an excellent performance in improving the transition from power optimization to power limitation of the wind turbine.