Abstract: Individual pitch control for load reduction on wind turbines is developed. Individual pitch control is decoupled into collective pitch control and differential pitch control, and the theory of collective pitch control and differential pitch control for wind turbines are studied. By Park’s transformation and inverse Park’s transformation, the differential pitch control which is a multiple input multiple output(MIMO) linear system is decoupled into two single input single output(SISO) linear system and the corresponding controller is designed by using linear control design techniques, so the individual pitch control can be much more practical to implement. As an example, a 1.5 MW wind turbine is simulated and analyzed in GH bladed software, and the results verify that via individual pitch control not only the function of collective pitch control can be realized, but also the fatigue loads of key components can be reduced.

Key words: Collective pitch control, Fatigue load reduction, Individual pitch control, Wind turbines