Dynamic Analysis of Flexible Wind Turbine Tower by a Transfer Matrix Method

Abstract

To generate more power, wind turbine rotors are growing in size and consequently, wind turbine tower are becoming increasingly taller and more flexible. As a result, fluid–structure interaction (FSI) of the flexible tower caused by strong wind is a very important phenomenon, and tower vibration must be carefully considered. In this paper, the physical model of the wind turbine tower is simplified appropriately, and then a multi-body dynamics model of wind turbine tower system is established based on Transfer Matrix Method of Multibody System (MSTMM). Compared with the data from finite element model (FEM) and field tests, the simulation results show that the model has a good accuracy. By coupling the mode shapes with two degrees of freedom (2-DOF) wake oscillator model, the dynamic responses of the flexible tower are computed. The influence of various foundation stiffness and top mass on tower vibration is studied systematically using this model. The results indicate that different boundary conditions can affect the maximum amplitude and displacement along the axis of the tower. This work provides a reference for dynamic modeling and simulation of high-rise flexible structure, and the prediction of the maximum amplitude of the tower vibration, which can be used for aeroelastic control purpose.