Vibration alleviation for wind turbine gearbox with flexible suspensions based on modal interaction

Abstract

Wind turbine drivetrains play a fundamental role in converting wind power into electrical energy. The gearbox is one of the most important and expensive components in a wind turbine drivetrain. Since flexible suspensions mounted on the gearbox are mainly designed for isolating vibration transfer to other turbine components, the gearbox itself still suffers from complicated whole-body vibration. In view of this, a vibration absorption method based on modal interaction is put forward to alleviate the whole-body vibration of the wind turbine gearbox with flexible suspensions. A vibration absorber with adjustable control parameters is utilized to establish modal coupling with the wind turbine gearbox. Internal resonance is analyzed and used to construct a modal interaction mechanism between the vibration absorber mode and the controlled gearbox mode. With the help of modal interaction, the vibration energy of the controlled gearbox mode is successfully absorbed by the vibration absorber mode and effectively dissipated by the damping of the vibration absorber mode. Through numerical simulations and virtual prototyping simulations, its vibration alleviation performance is verified. Since the proposed method is designed in terms of the controlled mode of the wind turbine gearbox rather than external excitations, it is suitable for applications in a complicated working environment. Besides, the proposed method aims to transfer and dissipate vibration energy through nonlinear modal interaction rather than suppress vibration via external energy, and thus can effectively deal with strong vibration problems. More importantly, it can easily work together with the existing vibration isolation method and further alleviate the whole-body vibration of the gearbox. This research will contribute to improving the reliability and service life of wind turbine gearboxes.