Study on arc characteristics and combustion feature of tree-wire discharge fault in distribution line

Abstract

In recent years, there have been cases of wildfires caused by electrical faults around the world. The arc plasma formed by tree-wire discharge can easily lead to wire damage or fuse, carbonization or combustion of branches.In this paper, a magnetohydrodynamic model of tree wire discharge arc is established by multi-physical field simulation, and the changes of arc shape characteristics and tree wire temperature under the influence of wind speed and wire type are studied. Then, the experimental platform is built to verify the simulation and measure the fault current waveform. Finally, the characteristics of the fault waveform in time domain and frequency domain are analyzed. The simulation shows that under the influence of wind, the arc root will shift, the arc temperature will decrease, and the two electrodes of the tree wire will be ablated. Through experiments, during the development process of tree-wire fault, the change of branch resistance is divided into five stages, and the leakage current is related to it. After being affected by wind, the pulse peak and zero current time of the fault waveform increase significantly and are positively correlated with the wind speed.The harmonic content is analyzed through frequency domain analysis, and monitoring the harmonic content during the fault process, combined with current characteristics, can effectively distinguish it from other HIFs, providing a reference for the study of arc characteristics and early warning of wildfires caused by tree-wire discharge in distribution lines.