Study on mechanical properties of tension strings based on ice shedding load

The shedding of ice from transmission lines can lead to intense vibrations in conductors, posing severe threats to the entire transmission system. This is especially detrimental to the fitting strings of transmission conductors. In order to investigate the impact of ice shedding from transmission lines on the fitting strings, a study was undertaken with the 420kN disc-type suspension insulator tension string with three units and double suspension points and 210kN single-unit tension string for ground wires from a specific transmission line as the subject. The test plan entitled “Tests on Dynamic Properties of Typical UHVDC Tension Strings” was designed for this purpose. The tension connecting plates within the two tension fitting string sets were tested separately under scaled-down conditions to yield their stress load status. Subsequently, the test results underwent validation using the finite element method, which revealed a robust correlation between test and finite element results, and notable stress concentration within the tension connecting plate. A finite element analysis was then executed on the two full-sized fitting string sets under hazardous conditions, and the stress results were found to both meet the material’s strength limit requirements. These tests serve as the reference for the mechanical properties of fitting strings during the process of ice shedding from transmission lines.