Design and hydrodynamic performance of 15 MW Spar-type floating offshore wind turbine platform

Objectives A new Spar-type floating wind turbine platform design scheme is proposed for a 15 MW floating wind turbine, and its performance is analyzed.

Methods Based on potential flow theory, the frequency domain hydrodynamic calculation of the platform is carried out and the wave loads and motion response characteristics of the platform under different wave directions are analyzed. The blade element momentum method is applied to calculate the aerodynamic load of the impeller and make it equivalent to the wind coefficient in order to calculate the time-domain response of the platform under the combined effect of wind, waves and currents under different working conditions, while also analyzing the force situation of the mooring lines.

Results The results show that the heave, roll, and pitch of the platform have peak points at the natural frequency of its motion, and the positions of occurrence are all far from the main energy region of the waves. Under the action of wind, waves and currents, compared to the working conditions, the maximum pitch angle of the platform under extreme conditions is smaller, but the amplitude of maximum surge, heave and mooring tension are greater than the working conditions.

Conclusions The newly designed Spar-type floating wind turbine platform has good stability and hydrodynamic performance. Under the designed environmental loads, its response and mooring force can meet the requirements of the specifications, ensuring the safety and stability of the wind turbine.