Vibration Analysis and State Assessment of 5 MW Test Wind Turbine in Frozen Environment

To investigate the effects of blade icing and anti-icing modifications on the vibration characteristics of 5 MW wind turbines in the winter icing environment of the Yunnan-Guizhou Plateau, and to evaluate their operational safety under complex climatic conditions, this study utilizes three anti-icing test turbines retrofitted with an active aerothermal method. Field vibration monitoring data spanning four months were collected. Nine vibration state variables at critical locations, such as the nacelle, were selected. By calculating characteristic parameters and applying threshold criteria, longitudinal and comparative analyses were conducted to comprehensively evaluate the vibration status and evolution trends of the turbines. The results indicate that the overall vibration severity of the three test turbines remains at a low level with negligible individual variations, and no abnormal fluctuations were observed. The mass imbalance and aerodynamic profile alterations induced by blade icing, as well as the load variations caused by the newly installed anti-icing equipment, did not lead to a significant exacerbation of turbine vibrations. It is concluded that, under icing conditions, neither blade icing nor the anti-icing modifications have a significant impact on the overall vibration levels of the 5 MW wind turbines. The structural dynamic performance of the turbines remains stable, demonstrating the capability for long-term safe operation.