Geometric modeling design and vibration modal analysis of wind turbine generator blade

Abstract

The wind turbine blade is the most complex part of wind turbine generator system (WTGS).The blade itself will produce flutter and divergence under the joint effect of vibration model and aerodynamic force. That the coupling resonance of tower and wind turbine impeller will be produced, when the natural frequency of blade flutter and the frequency of exciting force are the same, will seriously affect the stability of WTGS. This instability of system caused by the coupling resonance will also react upon the blade so as to appear blade fracture phenomenon. This paper analyzed and calculated the vibration model of the wind turbine blade under working condition with the finite element analysis software ANSYS and worked out the vibration frequency and vibration modes of the first nine orders. The analysis results show that the vibration modes of the blade mainly are waving vibration and shimmy vibration in working condition; the displacement values of shimmy vibration are bigger than the displacement values of waving vibration in the cases of similar frequency; Shimmy vibration is the most important vibration mode; In high-order stage, the vibration mode is the superposition of waving vibration, shimmy vibration and torsional vibration modes which is very complex. The results of the study provide the technical support for the improvement and optimization design of the stability of the whole WTGS.