Research On Rupture Mechanism And Improvement Measure For Armor Rods Terminal Of Overhead Ground Wire

The rupture accident of overhead ground wire wound by armor rods may occur at armor rods terminal under the action of short-circuit current.This will seriously affect the safe and stable operation of the power grid.Therefore,it is of great significance in engineering application to study the rupture mechanism of overhead ground wire at armor rods terminal and propose an effective improvement measure.Based on this background,the main research works carried out in the paper are as follows:1.Metal fractography analysis of the rupture sample.Macro morphological examination,Scanning Electron Microscope(SEM)and Energy Dispersion Spectrum(EDS)of an overhead ground wire rupture sample at armor rods terminal from Dongguan are conducted.According to the test results,rupture characteristics of overhead ground wire at armor rods terminal are inferred.2.Experimental study for transient temperature rise of armor rods terminal.Temperature rise experimental platform of armor rods terminal is designed,and the transient temperature rise experiments of armor rods terminal based on the short-circuit current and low curent are carried out respectively.The inferred rupture characteristics are verified by analyzing and extracting the damage characteristics of experimental sample.3.Simulation study of overhead ground wire at armor rods terminal based on multiphysics coupling.Three-dimensional finite element simulation model of armor rods terminal with electromagnetic-thermal-structural coupling is built.And variation of physical quantities of overhead ground wire at armor rods terminal is calculated and analyzed accurately in the case of short-circuit current.Moreover,the accuracy of the simulation model is proved by temperature rise experimental data.4.Summary for rupture mechanism of overhead ground wire at armor rods terminal and proposing an improvement measure.Combined with the simulation experimental results and calculation results,rupture mechanism of overhead ground wire at armor rods terminal is summarized.An improvement measure of armor rods terminal is also put forward.And effectiveness of the improvement measure is proved by the evaluation method for mechanical behavior of overhead ground wire at armor rods terminal proposed in this paper.