Power Quality in DC railway systems

Abstract

The topic of the power quality in railway systems has more and more interest driven by the need of having a reliable, efficient and resilient system. The paper contributes to the identification and cataloguing of transient and power quality events and power quality indices that affect the DC metro and railway systems. Several transient events detecting on-board the 3 kV and 1.5 kV traction units and in a 3 kV substation are presented and described. The behaviour of the amplitude and frequency content of the voltage and current ripple under a particular operating condition is described. The events have been extracted by the measurement campaigns performed in the framework of the European project MyRailS.

Traceability for AC Ripple Over DC Current

“…Successively with the invention of transformers, AC systems took over thanks to their competitive advantage for their better performances in terms of energy efficiency. Excluding specific high-voltage applications like submarine power transmission [1] or rail transport electrification [2], typically implemented in DC; electrical power has been almost exclusively generated, transmitted, and distributed in AC form for years. Nowadays, new technology for energy conversion re-enables DC distribution as a more energy-efficient solution.…”