Combined effects of icing and wind on transmission lines in mountainous areas

Abstract

To evaluate the changes in the state of pan transmission lines in mountainous areas under the combined action of icing and wind, a novel numerical computation method was developed using segmental catenary theory and the Runge-Kutta algorithm, which enables the handling of arbitrary three-orthogonal distributed and concentrated loads. Validation was performed through an example test and a comparison with two other numerical methods. Given the mountainous terrain, models for icing and wind loads were used to assess the combined effects on multispan lines. The conditions of non-uniform and uniform icing were compared, and the relationships of the unbalanced tension to the spatial parameters of the line are discussed. The results demonstrate that non-uniform icing causes more significant changes in the state of the line in the longitudinal direction compared to uniform icing, and the two icing conditions result in opposite trends in longitudinal unbalanced tension as the spatial parameters increase, suggesting the importance of considering the icing distribution on multispan transmission lines. The transverse changes in the line were primarily influenced by wind loading, which showed a weak correlation with icing conditions, whereas the transverse unbalanced tension exhibited a notable positive relationship with the spatial parameters of the multispan transmission line.