Study on jump height of transmission lines after ice-shedding by reduced-scale modeling test

The maximum jump height of a transmission line after ice-shedding determines the electric insulation clearance of the line. Reduced-scale modeling method for ice-shedding from conductor lines is presented and verified with the test results of two full-scale transmission lines. Dynamic responses of transmission lines after ice-shedding in the cases with different bundle number of sub-conductors, span length, elevation difference, initial stress in sub-conductors, accreted ice thickness, and ice-shedding rate were investigated by means of reduced-scale modeling tests. The vertical displacement and tension variations with time at typical points of the conductor lines after ice-shedding are analyzed. The formula calculating the maximum jump height of a conductor line after ice-shedding proposed previously based on numerical investigation is verified with the test results, and it is suggested that the formula can be used to define insulation clearance in the design of a transmission line in an iced zone.