Experimental study on dynamic response characteristics of isolated‐span transmission lines after ice‐shedding

Abstract

The dynamic response characteristics, including maximum jump height and unbalanced tension, of isolated‐span transmission lines after ice‐shedding are investigated by means of experiments. A reduced‐scale modelling method for ice‐shedding from conductor lines is presented and verified with numerical simulations and full‐scale test results in the literature. A parameter study on dynamic responses of isolated‐span conductors under three ice‐shedding scenarios, including whole span ice‐shedding, partial ice‐shedding and unzipping ice‐shedding, is carried out by means of reduced‐scale modelling tests. The effects of these parameters on the maximum jump height at typical positions and unbalanced tension in the tension tower are obtained. It is observed that the partial ice‐shedding scenario may be the worst situation for electrical insulation clearance rather than the whole span ice‐shedding scenario. Moreover, the position of maximum jump height along the span of isolated‐span transmission lines after ice‐shedding could be at around 2/5 of span length, which is different from the conventional opinion that the position is at the midpoint. The results may provide a foundation for the defining of the insulation clearance for an isolated‐span transmission line and the structure design of tension tower arms in an iced zone.

Experimental study on ice monitoring method for 10 kV transmission line with tangent tower in alpine landform

“…In the numerical simulation of ice, it is impossible to fully reflect the icing of the transmission line. The method of simulating ice load by the concentrated force method is relatively simple [25,26]. In Figure 10, the magnitude of the concentrated force is calculated by Equations ( 14) and ( 15) [23].…”

Analysis of Ice-shedding induced flashover accident on a transmission line in mountainous terrain

“…The research on ice shedding mainly focuses on the displacement at key positions of conductors and the dynamic tension, mainly including physical test methods, theoretical analysis methods, and numerical simulation methods. Among them, the physical test method includes full-scale tests and reduced-size tests [1][2][3][4]. The former directly uses real transmission lines to carry out experiments, and the results are closer to the ice-shedding reaction under real conditions, but the cost is high and the test is difficult [1][2].…”

“…The former directly uses real transmission lines to carry out experiments, and the results are closer to the ice-shedding reaction under real conditions, but the cost is high and the test is difficult [1][2]. The reduced-size test, using a small size or scaled reduction model, can carry out a large number of tests [3][4]. Because the ice-shedding process is a strong nonlinear movement, the reduced-size test is based on linear theory, so there are certain limitations in the test results.…”

Detection method for structural defects of U-shaped hanging ring for power fittings based on magnetic leakage principle

“…In recent years, with the rapid development of ultra-high voltage transmission line construction in China, accompanied by the characteristics of large transmission capacity and long spans across complex climates and terrains, higher requirements have been placed on the electrical performance, mechanical performance, reliability, and durability of overhead line power fittings [1,2]. Power fittings, serving in atmospheric environments, not only endure long-term continuous corrosion from corrosive mediums but also face the impact of intermittent wind-induced loads, accelerating the wear and deterioration of the fittings [3]. Through stress analysis of the overall models of tension and suspension string fittings in extreme environments, it has been found that the U-shaped ring is the component bearing the highest stress in the model [4].…”