Large-scale wind turbines usually have greater moment of inertia

so that the changes in rotor speed caused by wind speed variation lag behind

which makes the regulation of pitch angle feedback by the rotor speed not timely enough. As a result

the power output in the high wind speed zone fluctuates greatly. In order to improve the power output quality and quickly stabilize the rotor speed of wind turbines in high wind speed zone

the pitch control strategy based on aerodynamic torque feedback was proposed. Both characteristics of rotor speed and torque under the pitch angle changes were modeled and studied. The pitch controller was designed through the linear active disturbance rejection control(ADRC) theory. The aerodynamic torque was estimated in real-time. The sum of internal and external disturbance of the control system was observed by the extended state observer(ESO) based on the feedback of aerodynamic torque and was compensated. The simulation results show that

the power output fluctuation is much smaller and the adjustment time is much shorter by use of torque feedback than by use of rotor speed feedback. The LADRC is less dependent on the parameters of wind turbine

and the difficulty of parameter tuning is reduced while the control effect is guaranteed. The control strategy by use of the LADRC and torque feedback is of high value in engineering application.