Torsional Damping Considering both Shaft and Blade Flexibilities

A three-mass mechanical model that considers both shaft and blade flexibilities was used for the design of a torsional damper to damp drive-train vibrations in a wind turbine. Two torsional dampers were designed: one considering only the drive-train mode and another considering both the drive-train and blade in-plane symmetrical modes. The dampers performance was tested on a simple wind turbine model in Simulink® and then implemented in a more complete model in GH Bladed®. The simulation results on both wind turbine models correlate very well. This result indicates that a three-mass model is a good model for representing the shaft and blade flexibilities for designing a torsional damper. Simulation results show that considering both drive-train and blade in-plane mode frequencies when designing the torsional damper can lead to a better performance in damping torsional vibrations.