To mitigate cyclic loads in the wind turbine generator system (WTGS) caused by rotor unbalance

an adaptive individual pitch control (adaptive-IPC) strategy is proposed. Firstly

based on the relation of the rotational reference frame of blades and the fixed reference frame of hub

the loads characteristics are analyzed for a WTGS with unbalanced rotor. Then

considering that the frequency of the rotor unbalanced loads will vary with the speed of WTGS

a proportional-integral-resonant (PIR) based adaptive-IPC is presented in detail

with the resonant frequency of the R controller being adapted to the WTGS speed. And the pitch controller design method is also investigated. Finally

by using the FAST-MATLAB/Simulink based loads and control co-simulation system for WTGS

loads of a WTGS are simulated and compared in both balanced and unbalanced rotor condition. The load mitigation performance of the proposed adaptive-IPC is simulated with IEC turbulence wind speeds

and the results are compared with that of proportional-integral (PI) and proportional-resonant (PR) based traditional IPC strategies. Results show that the rotor unbalance will cause frequency-varying cyclic loads in the WTGS

and the proposed adaptive-IPC strategy is more effective than the two traditional IPC strategies. This work is supported by International Science & Technology Cooperation Program of China (No. 2013DFG61520)

National Natural Science Foundation of China (No.51377184)

Fundamental Research Funds for the Central Universities (No. CDJXS11151155) and Integration and Demonstration Program of Chongqing (No. CSTC2013JCSF70003).