Study on the prevention of conductor ice-shedding by interphase spacer

Conductor ice-shedding usually causes harm to the power system, which was a dominating factor in the just past great snow disaster in China. Ice-shedding on one hand will reduce the interphase clearance of transmission lines, which may lead to interphse flashover, and on the other hand will apply longitudinal unbalanced tension on the insulation strings, fittings and towers, which could lead to the breakdown of the towers. How to effectively prevent ice-shedding becomes a highlighted problem to be solved. In this paper, basing on 500 kV overhead transmission line, effective mathematical model including both the line and the interphase spacer is presented, and then the dynamic process of ice-shedding is computed, the results of which prove that it can reduce the jumping amplitude of the line as well as the longitudinal unbalanced tension acting on the insulation strings by installing interphase spacer. Furthermore, optimization of the installation scheme is analyzed, such as the amount of the spacers installed, the installing positions and the core rod diameter. Finally an optimal installation scheme is recommended to prevent the conductor ice-shedding, which is of great practical value for the safe function of the transmission line.