Influence of turbulent wind on dynamic response of articulated wind turbine

Abstract:

To meet the needs of offshore wind power development in medium depth water and reduce the cost, an articulated wind turbine was designed based on articulated platform. The influence of turbulent wind on the dynamic response of the articulated wind turbine in working and extreme sea conditions was studied. The blade element momentum theory was utilized to calculate the aerodynamic load and the potential theory was applied for the simulation of wave load. Considering the coupled loads of wind, wave, and current, the instantaneous change in wet surface as well as the friction damping of the articulated joint, a calculation software was written and time domain dynamic response of the wind turbine was calculated. Based on the NPD spectrum of turbulent wind, the dynamic response of the articulated wind turbine under the loads of constant wind and turbulent wind were calculated, and the influence of turbulent wind on the dynamic response and energy efficiency of the wind turbine was analyzed. Results show that with turbulent wind, the wind wheel acceleration and the vertical pull force on the articulated joint had little change. The mean values of oscillation angle, stream-wise thrust, output power, and stream-wise thrust force on the articulated joint decreased, but the amplitudes of oscillation angle and output power increased. In addition, the low-frequency characteristics of turbulent wind could increase the low-frequency response of the system and thereby cause system resonation. In extreme climate condition, the maximum stream-wise oscillation angle of the articulated foundation increased significantly, but the turbine system still met survival requirements. Hence, turbulent wind has great influence on the dynamic response of articulated wind turbine, and it is necessarily to consider the impact of turbulent wind when analyzing the movement and strength of articulated wind turbines.