AC cables strengthening railway low frequency AC power supply systems — A deepened study

In railway power supply systems using AC frequencies lower than the public grids of 50/60 Hz, high voltage AC overhead transmission lines in railway grid frequency are used as one measure of strengthening the systems. An increased resistance to overhead high voltage AC transmission lines, may motivate cables for future railway power systems. With the frequency of 50/60 Hz, reactive power produced in lowly utilized cables imposes an obstacle. For low frequency AC, this issue is less significant. Moreover, in converter-fed railways, no reactive power will leak into the feeding public grid. This paper studies AC cables in low-frequency AC railway. Two reinforcement cable solutions are compared with no reinforcement. A simplified load model of trains, with thyristor bridges and DC motors, is used.