A new pitch control strategy for wind turbines base on quasi-sliding mode control

Pitch control system is important part in variable speed variable pitch wind power generation systems. Since wind turbine is a strong coupling, high-order nonlinear system, conventional PI controller can not achieve good performance. Sliding mode control (SMC) has the characteristics such as fast response, small over-shoot, strong robustness and anti-disturbances. Sliding mode controller is suitable for the high-order, nonlinear, strong coupling system, however, sliding mode controller has the drawback of chattering. A quasi sliding mode controller is proposed to reduce chattering. The quasi-sliding mode variable structure control is analyzed in this paper. A pitch controller was designed based on quasi-sliding mode variable structure control strategy. Simulation results show that the proposed controller has better performance compared with conventional PI controller. Quasi-sliding mode control is simple and suitable for pitch control.