Dynamic analysis of two innovative tuned mass damper systems for a wind turbine using a 2-DOF model

Abstract

Reducing the cost of constructing wind turbines, as well as extending their design life, are two ways of reducing the cost of energy from wind. To achieve this, this project tested two innovative tuned-mass damper systems, which reduce resonance of the tower, and do so minimizing additional mass needed on the nacelle. These TMD systems allow the generator and full drive-train to oscillate with respect to the tower top. MATLAB was used to model these turbine-damper assemblies as simple 2-degree-of- freedom systems excited by thrust signals extracted from the FAST aeroelastic simulator. Furthermore, it was found that both tuned mass damper configurations have a net positive effect on the tower behaviour, both achieving double digit fatigue percentage reductions. It was also found that neither of these systems put significant burdens on acceleration-sensitive components, such as the generator and gear box. Two issues to constructing these devices may reside in their need for additional space for oscillations, as well as aggravated tip deflections in the case of the oscillating rotor-drive-train.