Individual pitch controller characteristics analysis and optimization under aerodynamic imbalanced loads of wind turbines

Individual pitch control technology can reduce asymmetric loads of wind turbines. The assumption of three completely symmetrical blades is the design premise of traditional individual pitch controller. However, production, assembly, and operation will inevitably lead to aerodynamic imbalanced characteristics for blades. Therefore, the failure mechanism of the traditional individual pitch controller is analyzed based on the frequency-domain decomposition method and verified by the simulation analysis. Based on the failure mechanism, the uncertainty modeling method is proposed to handle aerodynamic imbalanced loads. Then the robust individual pitch control is designed based on the product perturbation model. The D–K iterative algorithm is used to solve the H∞-optimization for the controller. The proposed robust individual pitch controller can effectively suppress imbalanced loads through simulation verification.