Effects of Ice Coating on the Maximum Discharge Distance During Ice-Shedding of Conductor-Ground Wire in 110 kV Transmission Lines

To address transmission line tripping caused by conductor-ground wire discharge induced by ice-shedding, this study developed a simulated 110 kV experimental platform to investigate ice-shedding discharge phenomena between conductors and ground wires. The research analyzed the impact of ice coating on the maximum discharge distance (MDD) and dynamically captured the arc evolution in conductor-ground wire gaps. Experimental results demonstrated that the MDD between an iced conductor and an uniced ground wire reached 14 cm under specific conditions, showing a 2–3 cm reduction compared to scenarios where both conductors and ground wires were iced under equivalent meteorological parameters. All measured values were below the 25 cm reference specified in the GB 50545-2010 standard. Synchronized analysis of arc characteristics and discharge current waveforms categorized the ice-shedding discharge process into four distinct phases: non-discharge, short-circuit arc, secondary arc, and insulation recovery, with a total arc duration of 61ms. Based on these findings, the study proposes utilizing image sensing resources from icing monitoring terminals in grid to detect ice-shedding discharge events in real time, providing a technical pathway for mitigating ice-related tripping risks in cold-region transmission systems.