Unbalanced load control method for low speed wind turbine based on state feedback
YANG Zhen yu1, WANG Qing1,2, WEI Xin gang1, YING You1,2
(1.Zhejiang Windey Co., Ltd., Hangzhou 310012, China;2.State Key Laboratory of Wind Power System, Hangzhou 310012, China)


Abstract: Aiming at the problems that 1P load control strategy could only reduce the 1P harmonic component of the blade and the 0P harmonic component of the hub could not restrain the high frequency vibration, a 2P load control method was applied to reduce the imbalance loads. By studying the dynamic characteristics of wind turbine and the equivalent linear model, theoretical dynamic equations and related loads equations of wind turbine was deduced. Due to the coupling of the system in the rotating coordinate, it was necessary to convert the system to the fixed coordinate through coordinate transformation so that the 2P load control method was applied appropriately. Using the load sensor mounted on the impeller, unbalanced load value was obtained as feedback signal, and state feedback controller was used to ensure real time load control. The results indicate that comparing with traditional 1P load control strategy the proposed method can effectively reduce the imbalance loads such as the 2P harmonic component of rotating parts and fatigue loads of fixed parts.

Key words: wind turbine; reduce the imbalance loads; state feedback controller; 2P load control