Effect of conductor geometry on bundle conductor galloping

A computer simulation of an elastic catenary was used to study the wake-induced galloping of a two-conductor bundle transmission line. It was shown that increasing the conductor separation reduces the region of galloping instability and decreases the amplitude of the resulting galloping. Stranded conductors are more likely to gallop at low wind speeds while smooth conductors gallop at high wind speeds. Since the fundamental frequency depends on span length, span has a large effect on galloping, with shorter spans being more susceptible. Twisting of the bundle one-half turn per span essentially eliminates galloping.