Analysis of Broken Lines at Overhead Ground Wire and Pre-twisted Wire Port Based on Skin Effect

Breakage and stock breaks are caused by the pre-twisted wire fittings of lightning protection lines in overhead transmission lines with power outages and even secondary disasters. In order to ensure the normal and stable operation of the power grid and reduce the wire breakage accident, it is studied that the heat generation of the overhead ground wire and the pre-twisted wire contact port in the paper. The ground wire and the pre-twisted wire contact point are equivalent to a uniform cylindrical conductive bridge, and the simulation model of the pre-twisted wire contact port is established. The radial and axial current density distribution curves of the grounding wire under the influence of the skin effect are analyzed, and the influence of current density on the contact resistance is studied. The key factor in influencing the contact resistance is the relative permeability of the material, and effective improvement measures are proposed accordingly.