Large wind turbines control using stable economic model predictive pitch technique with state constraints

This paper focuses on the wind turbine's pitch controller for the over-rated wind speed to harvest rated generator power by regulating the rated generator speed. The main difficulties in designing pitch control are pitch angle and state constraints, wind turbine nonlinearity, closed-loop stability, and providing economic operation. From that perspective, a new pitch control is proposed by utilizing a stable economic model predictive control (EMPC) technique for demonstrating the economic performance of variable speed/pitch wind-turbine (VSPWT) with persistent disturbance. This approach combines the dynamic economic and tracking optimization of the VSPWT pitch control into one online framework. An optimum linear feedback control is designed to guarantee the feasibility and stability of the wind turbine system by solving a constrained linear matrix inequalities (LMIs) problem. Using the nonlinear VSPWT model, standard and advanced pitch controllers are used for comparison with the suggested pitch control. Moreover, a 5-MW VSPWT typical simulator model is utilized for validating the proposed pitch control effectiveness. The results specify the suggested pitch controller's superiority over standard and advanced pitch controllers.