Analyse The Modal Dynamics Of Horizontal Axis Wind By Multi-body Model

Modern large wind machine blade, shaft and tower components such as flexible features, cause the system dynamics and its analysis method is different from the traditional relative rigidity of the wind turbine system. This study for large wind turbines in wind turbines under static and variable speed rotation vibration modal and its change characteristics of the elastic deformation, inertia and gyroscopic effect caused by each order modal system and its effect on the stability of aeroelastic system. The research for the design of large-scale wind turbine system and guarantee the safe and stable operation is of important theoretical and engineering application value.The 5WM offshore horizontal axis wind turbine blades of the United States Renewable Energy Laboratory was chosen as research subject, Superelement which can describe elastic deformation was used to scatter the flexible component into a series of rigid body. Based on the research of the linear eigenvalue analysis method, combining the dynamics analysis software ADAMS, multi-body system model of the whole machine system is established, the whole system under the static state of the linear eigenvalue problem was analyzed, and the system is obtained under the condition of the first ten order natural frequency and vibration mode, the relative movement of different parts on the vibration coupling effect of the form. Then, considering the elastic deformation of flexible component larger brought by nonlinear characteristic and the rotor rotation system brought by the time-varying characteristics of rigid integral method is applied to numerical control equations of the system, through frequency domain analysis method, has realized the rotor rotating under the condition of system operation mode identification, the system first ten order modal changes and its influencing factors in detail discussion and analysis.Jn addition, according to the structure characteristics of wind turbine, build the tree structure of the whole system topology structure, based on multi-body system dynamics theory, the nonlinear dynamic equation of the system, its numerical solution method is studied, using Matlab software to write the dynamics simulation calculation program. Through time domain of pulse excitation response and frequency response analysis, study the effect of the rotor rotation on its inherent characteristics, show that the rotor rotates, blade flapwise or edgewise vibration modal and rotor cyclotron forward and backward whirl modal coupling, rotor rotating gyroscopic effect caused by antisymmetry modal frequencies caused by the wind wheel speed. Study for optimal design of modern large-scale wind turbine system and elastic stability criterion, avoid resonance, improving the efficiency of the system and provides effective solution and analysis method.