Pitch Angle Control of Wind Turbine Based on Fractional Order PI and Integer Order PID Controllers

Pitch angle controller used in wind turbine to keeps its rated speed and aerodynamic output power in the high-wind-speed regions and release the mechanical tension of the drive train. Usually to control pitch angle an integer order proportional integral IOPI controller is used. In this paper an integer order proportional, integral and derivative IOPID and fractional order proportional integral controllers are utilized and designed with the same imposed tuning constraints which ensure a fair comparison. The aim of this work is to maintain the output mechanical power and rotational speed of the wind turbine at its rated values without variation and reduce the drive train stress caused by torsional torque. From the results of simulation, both of controllers give a satisfactory, but the FOPI controller perform better than the IOPID controller.