Aeolian Vibration of Conductors: Theory, Laboratory Simulation & Field Measurement

Abstract

The conductors of transmission lines are subjected to a variety of motions caused by the wind. The most common motions are aeolian vibration, sub-conductor oscillation (bundled conductors), galloping (generally associated with a light ice coating) and wind sway. Unless controlled, motions of conductors can produce damage to the conductor and other elements of the transmission system that will negatively affect the reliability and serviceability of the system. Sub-conductor oscillations, galloping and wind sway are associated with higher wind velocities, and in the case of galloping a light to moderate ice coating is required to initiate the motion. These motions are generally characterized as low frequency, high amplitude. Aeolian vibration, which is the subject of this paper, is associated with smooth (nonturbulent) winds in the range of 2 MPH to 15 MPH, and can occur on a daily basis. In contrast to galloping and sub-conductor oscillations, aeolian vibration is characterized as high frequency, low amplitude motion. This paper describes the theory of aeolian vibration, simulation of aeolian vibration in the laboratory to test the performance of conductor and conductor hardware, with a focus on how vibration damper performance is measured and finally the methods used to monitor aeolian vibration in the field on operating transmission lines.