Second order sliding mode controller and observer for a wind turbine system

Traditionally, the wind turbine system uses the conventional PID controller. However, the performance of the wind turbine systems can be enhanced using a more advanced control schemes. In this paper, a high order sliding mode (HOSM) control scheme is developed. First, the control scheme presents a robust aerodynamic torque observer based on super twisting algorithm in order to eliminate the sensors for the wind speed measurement. Second, a robust wind turbine speed control using a super twisting algorithm is also designed in order to regulate the rotor currents. The high order sliding mode control theory is employed in order to design this robust control scheme because as it is well known this control theory presents a good response in the presence of system uncertainties. Moreover, the high order sliding mode controller do not presents the problem of the chattering that usually turn up in the conventional sliding mode control schemes.