Role of Turbulence in Wake-Induced Galloping of Transmission Lines

Abstract

Linearized equations of motion are used in conjunction with power spectral analysis to analyze full-span oscillations of smooth two-conductor bundle transmission lines in turbulent winds. Assuming a von Karman model for low-altitude turbulence, it is found that, for low wind speeds, the response of the bundle is small for all equilibrium bundle tilt angles. As wind speed increases large-amplitude motions occur for tilt angles near 10°. These motions begin as horizontal galloping, but vertical galloping dominates for high wind speeds. Bundle rolling occurs only at the highest wind speeds considered.