Modelling the Dynamic Line Parameter of 25 kV AC Railway Electric Traction Lines at Earth Cuttings

摘要

Modern electric traction lines are mostly of 25 kV 50 Hz or 60 Hz systems. Shunt admittanceexists between earth and traction lines are considered to be uniformly distributed all along their length,and are conveniently neglected from calculations & design of the protection schemes. Fault distancelocating algorithms are also designed accordingly. Railway tracks in suburban area shall generally be laidon plane surface and be electrified. However, in developing countries, the railway tracks are electrified atnon-suburban areas also to a large extent, where tracks are laid through earth cuttings, tunnels, etc.Analysis on historical data collected from a real traction lines network from a non-suburban area whererailway tracks are laid through earth cuttings and tunnel revealed that the parasite capacitance between25 kV 50 Hz AC traction lines and the earth significantly varies with varying topographical features.Data collected and analyses from the experimental setup, and the validation tests conducted thereon onthe real traction line system are summarized in this paper.