Vibration stability of wind turbine structure under wind loads

The wind turbine structure is tall and bears large mass at the top. Dynamic instability is easy occurred in wind turbine structure under wind load. Due to many influencing factors of the instability of wind turbine structure, the relationship between part of variables and the stability of wind turbine structure is considered in current research. The relationship between certain structural variables of wind turbine towers and the stability of wind turbines has been considered in current research, but it lacks research on the comprehensive impact of multiple parameters on the structure of wind turbines under extreme wind loads. The most existing theories analyze the stability and safety evaluation of structures from a static and empirical perspective, with fewer results focusing on the mechanism analysis of structural catastrophic destabilization. A nonlinear vibration equation that accounts for the large deformation of the wind turbine structure is formulated based on the principle of the conservation of total potential energy. A method for assessing the stable vibration of wind turbine structures is developed based on cusp catastrophe theory. When the wind turbine tower fails to satisfy the conditions for stable vibration, the catastrophe displacement of the structure will happen as the frequency of external loads increases. The wind turbine structure will be catastrophic destabilization. When the stable vibration conditions are satisfied, the maximum wind speed can be increased by increasing damping coefficient and outside diameter of the tower. The maximum wind speed can also be increased by reducing the height of the wind turbine structure. The theoretical analysis results show close agreement with numerical simulation results. This method can provide valuable theoretical references and engineering guidance for designing wind turbine structures under extreme wind loads.