Analytical Determination of High-Frequency Propagation on Ice-Covered Power Lines

Propagation of high-frequency signals along a power line is adversely affected by deposits of ice or hoarfrost on the conductors. A difficulty arises in the application of conventional modal analysis to a study of the effects of ice on propagation since the lossy ice layer forms a discontinuity at its surface with the lossless air. An analytical method to eliminate this difficulty is proposed, based on the transformation of nodal charging current networks derived for ice-covered systems of parallel conductors. The method allows conventional lossy line analysis to be applied to propagation problems on ice-covered multiconductor power lines. Calculation of ice contribution to power line carrier attenuation on a two-pole dc line with bundled conductors is demonstrated.