Simulaton Research Of Flexible Structural Dynamics Of Large-scale Wind Turbines Based On Multibody Dynamics

In this paper, structural dynamics of wind turbine generator system and the key parts was analyzed. A new hybrid multibody systems approach for modeling the structural dynamics of wind turbine generator system is presented. The model is composed of flexible bodies such as blade and rigid bodies such as nacelle. The multi-rigid-body systems dynamics approach is used to model rigid bodies. The so-call superelement modeling method is used to approximate the wind turbine with a number of superelements consisting of a series of rigid bodies connected by springs and dampers. A set of motion equations was obtained by the Lagrange’s equations of the multibody system. The motion equations were solved by the solver in MSC.ADAMS. The 3-D model of wind turbine generator system is built by the three-dimensional design software SolidWorks. Dynamic characteristics and response analysis were realized by ADAMS/Vibration.The Wind turbine was divided into flexible sub-system and rigid sub-system. Flexible sub-system contains blades, tower and shaft and rigid sub-system contains hub and nacelle. Considering the fact characteristics, blades and tower dispersed to several rigid bodies with springs and dampers. The characteristics of springs were calculated by surperelement method. The characteristics formula was induced by equations of the bending beam deflection curve in material mechanics. Regardless of the linearly varying cross-section beam, two different methods have been used to calculate the stiffness of the springs.The dynamic characteristics of a 1.5 MW wind turbine and its tower and blade were figured out and the calculation precision and efficiency affected by the different methods were studied. Dynamics responses of the blade in working condition were displayed. Finally, Natural frequency and mode of the wind turbine generator system is calculated by the hybrid multibody systems model and frequency in working condition is calculated. The results show that the hybrid multibody system dynamic modeling method with fewer degrees of freedom can fully reflect the vibration modes of the system and this method is feasible analysis method for the aeroelastic stability analysis.