Passive Control of Spar Type Floating Wind Turbine using Effective Economic Optimal Design Values

This paper studies the performance of a passive linear tuned mass damper on controlling motion of a floating wind turbine. Controlled and uncontrolled analytical models of the spar FWT is established using Newton’s second law and conservation of angular momentum theory. The aerodynamic, hydrodynamic, mooring and buoyancy forces are determined and coupled with the system. For the controlled model, the TMDs are located in different locations and are tuned to different frequency ratios to reduce the motion of the FWT in different directions. The economic optimal design values are considered for the passive controller. The control performance is evaluated by the reduction of root mean square response in each degree of freedom. The results reveals that the linear TMD tuned to the frequency of pitch degree of freedom reduces the translational motion and rotational motion by 5% and 12% respectively. However, tuning the linear tuned mass damper to the frequency of surge degree of freedom provides 8% and 6% motion reduction in translational and rotational degrees of freedom. Also, it has been shown that installing the linear TMD inside the spar is more effective than installing the TMD inside the nacelle.