Model Predictive Control Based Active Power Control of Wind Turbines to Mitigate the Thrust Force

With the large-scale integration of wind power into the power system, it is urgent for wind turbines to have the active power control capability. However, achieving the active power control goal through passive speed variation (PSV) will increase the tower fatigue load. This paper reveals the mechanism of the frequent and large fluctuations in the thrust force caused by the rotor speed control (RSC), during the start-up stage of pitch angle regulation from the perspectives of pitch adjustment amount and sensitivity. The attention should be paid to the pitch adjustment amount during the start-up stage, to address the problem of excessive pitch adjustment due to overactive PI regulation. Hence, the model predictive control (MPC) based APC methods is proposed for better coordination between pitch angle adjustment amount and rotor speed limit objectives. The result shows that MPC can effectively reduce the adjustment amount during the start-up stage, and achieve the goal of suppressing the tower fatigue load.