Analysis of Contribution of Full Summation Hydrodynamic Load to Dynamic Response of Floating Offshore Wind Turbine Structure Operating in Extreme Environments

Since most of the floating offshore wind turbines are in the hurricane's path, it is essential to analyze the dynamic safety caused by the hurricane. At extreme wind speeds, the influence of hydrodynamic loads is relatively increased because the turbine is idling. In addition, the semi-submersible offshore wind turbine (FOWT) causes a slow drift motion due to the difference-frequency load of low-frequency, and the sum-frequency load of high-frequency load can stimulate the fore-aft, side-to-side of the tower. Therefore, we use the hurricane-progressed hourly atmospheric and ocean energy data obtained from numerical simulations since an analysis of the total load is required to determine the contribution of hydrodynamic loads. In addition, the extreme sea-level change limited the effective range of wave steepness and cut-off frequency in calculating the full summation load of the potentional theory. Furthermore, the atmospheric data for the turbine are obtained by calculating the mean wind velocity along the path of a hurricane's eye. Finally, it was derived that consideration of the total load is essential to analyze the dynamic performance of the FOWT according to the extreme environment.