Structural vibration control of offshore floating wind turbine based on TMD

In order to suppress the responses of the large vibration loads and deflections of the offshore floating wind turbine under the extreme wind and wave conditions, a passive tuned mass damper (TMD) is introduced to the dynamics control field of the floating wind turbine, and the fully coupled aero-hydro-control-TMD-structural dynamics model of the floating wind turbine is established in this paper. Parameter optimization of the TMD is researched based on the typical 5 MW barge-type floating wind turbine. Five typical combined wind and wave load cases are selected under normal running state of the wind turbine; the dynamic responses of the wind turbine with/without TMD are simulated and the suppression effect of the TMD is investigated. The results and their analysis show preliminarily that: (1) The standard deviation of the tower top longitudinal deflection is decreased 45.7% in 100 seconds by the optimized TMD, so the optimized TMD can suppress the vibration in the form of the most important modal effectively. (2) The suppression rates of the standard deviation of the longitudinal loads at tower base and deflections at tower top are 20%~50% and those of the longitudinal loads at blade root and deflections at blade tip are 10%~40% by the optimized TMD, which show that the optimized TMD can reduce the vibration loads and deflections of the key parts in wind turbine significantly under actual environmental conditions.