Some aspects of impact analysis of a planned new 25kV AC railway lines system on the existing 3 kV DC railway system in a traction supply transition zone

摘要

The main aim of the article is to present possibility of negative influence of an AC 25kV traction system on the existing DC 3kV railway system and power network, due to the unbalanced AC traction load. In the article, apart from the main problems which could appear in the transition zone of AC and DC railway systems, the analysis of each system in separation is performed. Article also contains some aspects of voltage unbalance calculations and estimations. A Matlab — Simulink model of the DC and AC traction systems is done.