Dynamic Response of Ice-Shedding Jump of Iced Quad-Bundled Conductors Under Ice–Wind Coupling Effects

Ice shedding from transmission conductors may induce severe vertical jumps and sudden tension variations, threatening the electrical clearance and structural safety of transmission lines in heavy ice areas. To investigate the coupled effects of wind load, ice accretion distribution, and ice-shedding mode, this paper establishes a dynamic model for the ice-shedding jump of an iced quad-bundled conductor considering wind action. The conductor is discretized into cable elements and nodes, and the aerodynamic forces are updated in real time according to the relative wind speed, attack angle, and wind-tunnel-based force coefficients. The model is verified by mesh, time step and damping sensitivity analyses, compared with published numerical results without wind, and checked for consistency with wind-tunnel-based trends under wind load. Based on the proposed numerical model, the effects of wind speed, attack angle, ice accretion pattern, and ice-shedding mode on the maximum jump height Hmax and its spanwise location Pmax are analyzed. Neglecting non-uniform ice accretion underestimates the jump after whole-span shedding by a factor of 2.4–6.8, whereas the response to half-span shedding is insensitive to the ice distribution (within ±10%). The amplification at high wind speed results from the sudden reduction in the downward aerodynamic load on the shed section, which grows with U2 and outweighs the aerodynamic damping of the vertical motion. For a 500 kV vertical arrangement, half-span shedding reduces the phase-to-phase clearance to 3.5–4.5 m, which satisfies the power frequency requirement but not the switching overvoltage requirement of GB 50545-2010.