Vibration attenuation for offshore wind turbine by a 3D prestressed tuned mass damper considering the variable pitch and yaw behaviors

Abstract

Large megawatt offshore wind turbine (OWT) is a complex dynamic system with variable pitch and yaw functions, resulting in the bidirectional variable stiffness of blade and direction misalignment of wind-wave loads at the operation condition. This paper provides a new perspective to tackle the vibration attenuation problem of the OWT system considering the mechanical operation behaviors with a three-dimensional prestressed tuned mass damper (3D-PSTMD). Firstly, the motion equation of OWT with 3D-PSTMD system considering the variable pitch behavior is established by the Lagrangian equation. Then, the aerodynamic load and hydrodynamic load considering the yaw behavior are simulated via the Blade Element Momentum (BEM) method and Morison's equation. Furthermore, a numerical simulation example from NREL 5 MW is performed to analyze the structural dynamic responses considering the variable pitch and yaw behaviors. Finally, the dynamic responses of uncontrolled and controlled OWT systems are calculated to evaluate the vibration attenuation performance of 3D-PSTMD under the aerodynamic and hydrodynamic loads, and results showed that 3D-PSTMD can notably mitigate the dynamic responses of blade tip and tower top in fore-aft and side-side directions.