Arcing in AC railways: a mathematical approach

摘要

The growing use of electronic devices for communication and control in the new AC railways suggests a deepened study of electromagnetic interferences. Amongst the dynamic phenomena the more interesting one is the interference produced by the arcing due to the pantograph de-wiring from the contact wire. This phenomenon determines interference with a wide frequency spectrum up to several GHz, and with a not negligible magnitude. The analysis of this kind of phenomenon represents a complex issue, due to the lack of experiences and mathematical models able to describe completely and in a easy way the electromagnetic phenomena and its interaction with the electric environment. Starting from the results of previous studies, the paper shows an accurate arc resistance model for AC systems. The obtained arc model is used in an high frequency model of an AC railways and it takes into account both the power supply system and the on board traction drive. The results of some simulations are presented to highlights the EMIs (Electromagnetic Interferences) due to the arc ignition. An analysis of the voltages and currents of the system are carried out to evaluate the propagation of the disturbance along the line and the effects on other electric vehicles running on the track.