Railway track transmission line parameters from finite element field modelling: Shunt admittance

An electromagnetic field model for identification of rail track equivalent multiconductor transmission line distributed self and mutual shunt admittances is formulated and used to illustrate the parametric behaviour of single-track admittance. Verification is achieved by reference to fundamental theoretical analysis and comparison with published experimental data. The results confirm that the value of track admittance is dependent on the sleeper, ballast and ground frequency-dependent material properties with the ground moisture content as a key variable.