Abstract: According to the problems of over large pitch load and instable output power and voltage of the independent variable pitch wind turbines, the model reference adaptive control(MRAC) method was used to study the optimal control of independent variable pitch of wind turbines. The selection process of reference model was discussed. The controller was designed based on Lyapunov stability theory and applied to the independent pitch. The simulation results show that the control method not only improved the response speed of the pitch controller but also improved the tracking accuracy, and stabilized the output power and voltage. Meanwhile it reduced the blade flapping vibration. The model reference adaptive controller can be used for wind turbine control.

Key words: independent pitch control, model reference adaptive control(MRAC), Lyapunov stability theory, system model, tapping vibration