Ice shedding from overhead transmission lines in the ice region will lead to the reduction of insulation clearance, which may lead to flashover trip or tower collapse, threatening the safe operation of the grid. Previous studies assumed that the conductor is uniformly coated with ice, i.e. the ice thickness is consistent along the span. Recent accident investigation found that in the complex microtopography and micrometeorology area, the thickness along the span is different i.e. non-uniform ice-coating, inducing the flashover due to ice-shedding situation. However, there is no research on dynamic characteristics of wire deicing jump under non-uniform icing. This paper focuses on the dynamic responses of bundle conductors after ice-shedding under non-uniform ice-coating condition, and proposes some effective measures to improve the ability of anti-ice problem. Firstly, the FE model of the transmission line to simulate ice-shedding was established in ABAQUS software, which was validated by comparison with test results in the literature. The dynamic responses after ice-shedding under different non-uniform ice-coating conditions were investigated. The maximum jump height and unbalanced tension in the conductors were obtained, and both the maximum ice jump height and unbalanced tension under non-uniform ice-coating of the conductor are greater than those under uniform ice-coating. It is obtained that the dynamic responses of bundle conductors after ice-shedding under non-uniform ice-coating are more dangerous than those under uniform ice-coating, which illustrates the necessity to consider the influence of non-uniform ice-coating in the evaluation of ice-shedding effect.

transmission line; non-uniform ice-coating; jump height; dynamic response