Modeling of Blade Vibration Mechanism at Edgewise and Flapwise in Horizontal Axis Wind Turbines

The vibration mechanism of wind turbine blade is modeled as the foundation for studying blade vibration patterns and conducting fault diagnosis. A coupled structural dynamic and aerodynamic model of horizontal-axis wind turbine blade edgewise and flapwise vibrations is established by considering factors such as tower shadow effect, geometric nonlinearity, and pitch angle variations based on multi-coordinate transformations. The multi-body dynamic models are constructed for a 2 MW wind turbine flexible blade and a 3 MW wind turbine blade at one on-site wind farm, and the results show relatively high agreement with the calculations from GH Bladed software and measurements from actual blade. Based on this, the effects of tower shadow, geometric nonlinearity and pitch angle variations on blade operating parameters and vibration under steady-state conditions are studied. The results show that the axial thrust and torque of the blade decrease significantly in the tower shadow area. At the same time, there is a sign