Dynamic Response Characteristics of Ice-Shedding in Isolated Span Conductors under Non-uniform Ice Accretion

Ice shedding from transmission lines under dynamic excitation can trigger conductor, potentially reducing phase-to-ground clearance below safe limits and leading to flashovers or line trips. To investigate this phenomenon, a finite element model of an isolated-span conductor was developed based on the Sichuan-Chongqing UHV AC transmission project. A non-uniform ice accretion coefficient was introduced to represent spatial variation in ice thickness. The influence of span length, elevation, ice thickness, wind speed, and shedding mode was analyzed under different ice non-uniformity levels. Under full-span shedding, height increases with both the non-uniformity coefficient and span length. The most significant amplification (1.63 times that of uniform icing) occurs in the 500 m span with a 300 m elevation difference. Partial-span shedding is identified as the most severe condition, producing peak heights-up to 5.16 times that of full-span shedding-typically located at one-third of the span. Generally, longer spans and thicker ice lead to larger responses. Elevation difference has opposite effects depending on the shedding mode. Wind speed also intensifies both height and conductor tension. These findings offer theoretical support for optimizing line design and de-icing strategies in heavily iced regions.