Study on the Characteristics of Non-uniform Ice and Jump afer Ice-shedding of Isolated Lines in Heavy Ice Areas

Deicing jump is the primary cause of faults and shutdowns in ultra-high voltage transmission lines. The research on re icing after uniform icing has been relatively mature, but in recent years, many accident analyses have shown that re icing after non-uniform icing is the main cause of ice disasters in transmission lines. The existing numerical simulation research mainly considers the dynamic respond under uniform icing conditions, with less consideration given to non-uniform icing conditions, which cannot fully match the actual situation. This article establishes a finite element simulation model for non-uniform icing and icing of conductors, and conducts research on the non-uniform icing characteristics of isolated span conductors in heavy ice areas; Through numerical simulation, reveal the influence of uniform and non-uniform icing on the sag of isolated conductor. The results show that the sag of icing on non height difference transmission lines increases as the non-uniform icing coefficient growing; The sag of icing on transmission lines with height differences decreases with the increase of non-uniform ice coefficient; The maximum ice jump height increases as the uneven ice coefficient growing for transmission lines with height difference and non-height difference, and the location where the maximum ice jump occurs will be far from the midpoint of the span; The impact of the de icing method on the ice jumping height of isolated lines is higher than that of the icing method; The current empirical formula is applicable for isolated transmission lines with full de icing at large spans, but it is not applicable for small spans or partial de icing.