Study on icing characteristics of bundled conductor of transmission line based on shadowing effect analysis

Abstract

Icing on transmission lines significantly threatens the safety and stability of power system. Particularly for bundled conductors, the shadowing effect of the upwind conductor on the downwind one affects airflow and droplet distribution, leading to unique icing characteristics. This paper employs numerical simulations and icing tests to investigate the icing shadowing effect of bundled conductors. Firstly, the distributions of airflow and droplets around the bundled conductor are solved by the Eulerian-Eulerian two-phase flow model. Then, by solving mass and thermodynamic balance equations, the icing mass and shape accreted on the bundled conductors under various icing conditions are obtained. Further, two novel parameters, the shadowing coefficient and the offset angle, are introduced to quantify the shadowing effect's impact on ice mass and shape. The findings indicate that the ice mass ratio on the downwind conductor to the upwind conductor is influenced by wind speed, wind angle, bundle spacing, conductor diameter, and droplet parameters. In most cases, the ratio is less than 1; however, under certain wind angles, this ratio exceeds 1. The shadowing effect also impacts the ice shape on the downwind conductor, inducing an additional offset in the ice shape. The magnitude of this offset angle is also correlated with environmental parameters. Finally, the accuracy of our numerical simulations is validated by the outcomes of natural icing tests.