Structure Analysis of an Innovative Vertical Axis Wind Turbine with Inclined Pitch Axes using Finite Element Method

Abstract

Abstract Pitch regulation is critical to power performance of wind turbines. However, the complexity of the conventional pitch system of vertical axis wind turbines (VAWTs) retards its appliance. In the present study, an innovative pitch system of a VAWT with inclined pitch axes was proposed where a slider in the main shaft actuated upwards or downwards drives blades to be folded by linkage mechanisms. Effect of design parameters of the pitch system on blade folding movement control sensitivity was evaluated. Loads of pitch hinge, deformation of blades and stresses of components were analyzed as well as natural frequencies of the wind turbine with various azimuth and fold angles under rated operational conditions by finite element method and effect of design parameters on structural performance of the wind turbine was investigated. It was found that deformation of blades and stresses of supporting arms deteriorated but natural frequencies of the wind turbine increased when blades were folded in the negative direction. In addition, the increasing arm interval height improved structural performance with the increasing natural frequencies. In the contrary, the decreasing blade linkage length, shaft linkage length and slider height improved structural performance with the decreasing natural frequencies. This study laid the foundation for the further design optimization of the novel pitch system.