Azimuth weight coefficient based independent variable pitch control strategy

In order to decrease the fatigue of units caused by imbalance loads, the weight number assignment variable-pitch control strategy based on the azimuth angle signal of the pitch was presented according to the aerodynamics principle, wind shear characteristic and tower shadow effect. First the collective pitch angle is acquired according to the output power approximately equal to the rated power, then the blade pitch angles are redistributed through the related weight number according to each wind turbine blades under different wind speed. So the collective pitch angle was transformed into the individual variable pitch angle. At last, the collective pitches and individual pitches systems are designed, and mathematical models are built using MATLAB. The simulation results show that the proposed strategy not only ensure the pitch angle to change with the wind speed and obtain the stable output power, but also reduce the loads of blade and prolong service life of wind turbine, it has better dynamic performance and static error than general collective pitch control and easy to implement.