Differential displacement and strain analysis of transmission line cables

Research on Failure Mechanisms of Broken Strands of Jumper Wires for EHV Transmission Lines in Strong-Wind Areas

“…There are persistent slip marks and persistent slip bands on the surface when fatigue damage accumulates. These slip lines tend to widen with the increase in the level of simulated wind speed, indicating that the yield degree of the aluminum-wire surface increases [21,24]. From the 3D profilometer measurement shown in Figure 15c,d, the depth difference in the yield line is up to 5-10 µm, and the width is up to 30-50 µm, which is way above the 1-µm scale of normal roughness of a new aluminum-wire surface.…”

“…Thus, the jumper wire has the same swing angle 1. Therefore, by generating the same swing angle, the machine can reproduce the swing condition of the jumper under the same wind speed [24,25]. Figure 10 shows the schematic diagram of the simulation machine.…”

Characteristics of Wires of the Long-Operated Aluminum-Steel Cable at Different Places on an Overhead Power Line Span

“…Earlier, to investigate the processes occurring during the operation of cables, cables were studied not only immediately after operation in OPLs [5,11,12,14,15,[24][25][26]30,34] but also after fatigue tests [6,16,[20][21][22][23][27][28][29][31][32][33]35,36], which simulated "aging" of wires (changes in microstructural, structural, and other properties) under real operating conditions or after heat treatment [8][9][10]. Both AAAC [6,8,16,[20][21][22][23][24][25][26][27][28]36] and ACSR [5,6,11,12,14,15,26,[29][30]…”

“…For instance, the effect of both tensile mechanical stress [20,21,28,29] and the amplitude of displacements at bending [6,[21][22][23]28,29,31,35] were investigated, as well as that of annealing temperature [8,9] and mechanical defects of Al wires during their production [7], effect of clamp material [23,31], elemental composition of Al wires [6,22], presence of a steel core [6,26], corrosion due to exposure to ambient air during operation in power lines [5,14,15,30], forest fires [10], and the environment during fatigue tests (either room atmosphere or NaCl solution) [32]. Changes in the microstructure, structure, chemical composition, and physical properties of wires from cables were also studied after their operation in OPLs for various service lives ranging from 8 to 62 years [5,11,12,14,15,[24][25][26]30,34] and after fatigue testing [27,36].…”

“…In the papers [5,[24][25][26], where cable wires were studied after operation in OPLs, and in most of the papers devoted to the results of fatigue tests [6,16,20,22,28,32,33,36] and to the studies of various physical properties of the wires after fatigue tests [27,35,36], the positions of the wires in the cable cross-section or along the cable length were not fixed.…”