Model of Thermomechanical Vibrations of Current-Carrying Conductors

Abstract

In the operation practice of overhead power transmission lines (OHL), the phenomenon of "galloping" of conductors is well known – vibrations with frequencies of ~ 1 Hz and with amplitudes of the order of the static sag [1, 2]. This phenomenon is observed, as a rule, when the symmetry of the conductor section is violated due to icy deposits, which gives the conductor some aerodynamic efficiency. However, this model does not explain all the observed cases of galloping. In this regard, it is advisable to pay attention to the little-known experience of Academician Abram F. Ioffe, who experimentally discovered the self-excitation of a current-carrying conductor – a stretched string that heats up when connected to an electrical circuit. Solving this issue can significantly expand the understanding of the nature of conductor galloping and open up new ways to fend off this phenomenon, which poses a danger to the stability of the functioning of energy systems. This requires a mathematical model of the OHL conductor describing the interaction of mechanical and thermal processes. The purpose of this work is to construct the simplest version of this model, on the basis of which the condition of self-excitation of thermomechanical self-excitation of real OHL conductors can be justified.