Abstract:The risk assessment method for ice-shedding of overhead lines under ice and wind loads was proposed in this paper. Firstly, the variation data of vertical jump height, lateral swing and dynamic tension at the end of the transmission line are obtained under different ice-shedding modes. Secondly, the minimum inter-phase clearance of ice-shedding transmission lines, impact coefficient, the maximum unbalanced tension of suspension clamp and safety coefficient for the mechanical strength of the tension insulator strings are calculated. Then, the risk of transmission line discharge, wire breakage, damage to suspension clamps, and damage to tension insulator strings are analyzed and the risk assessment results of ice-shedding transmission lines are output. The method of simulating ice-shedding load and instantaneous wind load by using step function is proposed. The calculation method of the minimum inter-phase clearance of ice-shedding transmission line under ice and wind load is put forward. The 110 kV overhead line in southern China is taken as an example to verify the effectiveness of the proposed risk assessment method. The results show that the dynamic tension at the end of the conductor decreases quickly when the ice-shedding occurs from the C-phase conductor of the 110 kV transmission line, and the maximum vertical jump height and the maximum lateral swing of the C-phase conductor are 1.84?m and 11.6?m, respectively. The maximum unbalance tensions at the end of the tension strings and at the end of the suspension clamps are 44?kN and 85?kN, respectively. There are both electrical and mechanical risks in the transmission line at this time. The results of the risk assessment are consistent with the results of the actual accidents, which verifies the accuracy of the proposed risk assessment method.