Vibration monitoring on aerodynamic asymmetry of wind turbine
                                                   LI Xueping, ZHUO Peijun, LUO Yongshui, ZHOU Minqiang
                                                                 (Zhejiang Windey Co.,Ltd., Hangzhou 310012, China)

Abstract: Aiming at the problem of online monitoring of aerodynamic asymmetry fault, the vibration characteristics of the wind turbine under such fault were analyzed. Both the axial and lateral vibration at different positions in the nacelle with and without aerodynamic asymmetry fault were mearsured.A rotor aerodynamic asymmetry online monitoring and protection strategy was further proposed based on the 1P vibration of the wind turbine. The effective value and amplitude of the 1P vibration can be monitored by this system in real time and a delayed alarm strategy was utilized to avoid false alarm. The results indicate that the 1P vibration significantly increases under rotor aerodynamic asymmetry fault, and the axial vibration changes compared to the lateral vibration are more obvious.Furthermore, the online monitoring system has fast response speed and high reliability,which is of great significance to the safe operation of the wind turbine and development of blade damage diagnosis technology.

Key words: wind turbine; aerodynamic asymmetry; 1P rotational frequency; online monitoring and protection