Aeroelastic Damping Analysis Of Large Horizontal Axis Wind Turbine

Aeroelastic damping analysis of large horizontal axis wind turbine is always as an important research topic in the field of wind turbine. Wind turbine is becoming larger and more flexible, because of the flexible deformation of components of wind turbine coupled with time-varying aerodynamic load has a great influence on the stability of wind turbine operation. Aeroelastic damping of blade is one of the most important factor which influences the stability of wind turbine operation. So the researchers at home and abroad pay attention to the aeroelastic damping analysis. This paper is based on the modeling method of modern computing multibody dynamics, build the dynamic model of wind turbine and single blade, implement impulse response analysis of wind turbine and single blade. Combining with the aerodynamic load model of blade, get the aeroelastic coupling response of blade under the action of constant wind speed and turbulence wind speed. Get the amplitude frequency characteristics of impulse response and aeroelastic coupling response by discrete Fourier transform of time domain response, then get the structural damping of blade and tower and the aeroelastic damping of blade based on half-power bandwidth method. The research content and the result have important theoretical significance and practical value.The5MW offshore horizontal axis wind turbine blades of the United States Renewable Energy Laboratory (NREL) was chosen as research subject, Superelement which can describe elastic deformation was used to scatter the flexible component into a series of rigid body. Multibody system model and dynamic equation of wind turbine and single blade were obtained by the modeling method of hybrid multibody system based on the theory of computational dynamics of multibody system, implement impulse response analysis of wind turbine and single blade, then get the amplitude frequency characteristics of the system from discrete Fourier transform of time domain response and impulse load, analysis the amplitude frequency characteristics of blade and whole system based on half-power bandwidth method to get the structural damping ratio. Implements the aeroelastic coupling simulation of the blade Combined with the component of aerodynamic, get the amplitude frequency characteristics of the system from the Fourier transform of the time domain response of blade, analysis the amplitude frequency characteristics of blade based on half-power bandwidth method to get the aeroelastic damping ratio.A general simulation program which can numerical solve the dynamic equations of multibody system was designed based on MATLAB. The natural frequencies of blade, tower and wind turbine were analyzed by the program and ADAMS/Vibration respectively, the effectiveness of the program and the correctness of the modeling method were verified by comparing the results with those of NREL. The results show that superelement modeling method can accurately describe the coupling among the elastic deformation of flexible body and dynamic loads and its displacement well. The modeling approach of hybrid multi-body system is suitable to build the dynamic model of wind turbine system and the program is a feasible analysis platform for the aeroelastic coupling and stability analysis of wind turbine.