Abstract
Due to the funneling effects of valley terrain, intensified wind and rain may cause conductor galloping, line breaking, insulator flashover and even tower collapses. Researchers are mainly concerned about the distribution of wind velocities within valley terrains, and very few of them studied the characteristics of wind-driven rain and its effects the motion of the suspended high-voltage conductor. The objective of this paper is to investigate the characteristics of wind and rain in a simplified valley and their effects on the motion of the high-voltage conductor. The distribution of wind velocities in the simplified valley is computed by computational fluid dynamics method (CFD), of which the results demonstrate that the valley length has a stronger effect on wind velocity compared to flat terrain, and the maximum speed-up amplitude of wind velocity reaches 67% which apparently higher than 10% specified in Codes of GB 50545-2010. Meanwhile, the velocities and the trajectories of raindrops are calculated with finite difference method, and the results show that raindrops’ velocities in the valley terrain increase rapidly than that of in the flat terrain. Then an analytical model based on the finite element method is proposed to study the effects of wind and rain on the motion of the high-voltage conductor suspended over the simplified valley, and the results show that the maximum percentage of vibration amplitude by rain-wind loads relative to wind loads can reach to 8% (in-plane) and 19% (out-of-plane). Therefore, wind and rain in the valley terrain obviously different from that of in the flat terrain and should be give more attention in the design and operation of transmission lines.
Published Version
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