Design of pitch controller for wind turbines using time-delay estimation

To increase the length of life and the stability of wind turbines, the output power of wind turbines should be restricted under the rated power. Especially, in order to guarantee the restriction, it is essential to use a pitch control above the defined rated wind speed. This paper presents a design method of a collective pitch controller for wind turbines using time-delay estimation (TDE). TDE estimates nonlinear and unknown terms in system dynamics. Time-delay Control (TDC), which is a control method based on TDE, uses the estimated information to track the desired trajectory. The pitch control technique with TDC is operated in all operating regions. The effectiveness of the proposed controller is evaluated with computer simulations using FAST aeroelastic computer aided engineering tool. And these simulations are conducted by comparing with conventional PI controller.