Modeling and simulation of arc and contact wire molten pool behavior during pantograph lowering process

Contact wire is an essential part of traction power supply system in the electrified railway, which on the one hand transmits the electrical energy, and on the other hand plays as a smooth track for the current collection strip. In the daily operation of the electrified train maintenance, the contact wire suffers from the arcing ablation during the pantograph lowering process. Potential contact wire breakdown might take place. In this paper, the surface erosion of the contact wire by the pantograph arcing was studied numerically. A multi-physical model dedicated to the contact wire erosion issues was established, with the process of heat transfer, phase transition, and liquid metal flow taken into account. Characteristics of the surface erosion, the temperature field as well as the flow field under different current conditions were studied respectively. Particularly, the Marangoni effects on molten pool evolutions were examined, which could have a significant influence on the final erosion characteristics. This work might be helpful for the further understanding of the basic physical process of the contact wire erosion by the pantograph arcing, and as well as providing a meaningful reference for the performance improvement of the current collection system.