The effect of aerodynamic torque on the rotation of an overhead line conductor during snow accretion

Abstract

The purpose of this paper is to develop an approximate analytical solution for the rotation of a conductor, of finite span and finite torsional stiffness, caused by wet-snow accretion. The accretion process for the conductor/snow system depends on meteorological parameters, parameters controlling the adhesion of snowflakes on impact, snow densification, mechanical properties of the system and aerodynamic forces. In the early stages of wet-snow accretion the mechanical behaviour of the system is described by a nonlinear wave equation governing the rate of change of angular momentum of the rotating conductor due to the snow and aerodynamic torque. This equation can be solved by the method of two-time scales, yielding solutions which are in excellent agreement with results derived from a mathematical/computational model. The analysis highlights the important effects of conductor rotation on snow load.