Observer-based backstepping control of the half-direct permanent magnet wind power generation system

In this paper, an observer-based backstepping controller is presented for the half-direct permanent magnet wind power generation system. The technology of backstepping is introduced to design the controller for maximum power point tracking at the operation region with low and moderate wind, and the high-gain observer is designed to estimate the unmeasurable variables needed for the controller design. Moreover, a switching mechanism is proposed, in which an online rotational speed is defined for the startup-to-grid-connected switch of the half-direct permanent magnet wind power generation system. Then, the stability of the designed closed-loop controlled system is analysed, based on the Lyapunov asymptotical stability theory. Simulation results are presented to show the efficiency of the proposed control law.