Electromagnetic field modelling for transmission line distributed parameters of railway track

The authors describe modelling to determine frequency-dependent distributed rail track impedance and admittance for solution by the finite element method. The equivalent transmission line track model is excited by the TEM propagation mode. Maxwell´s equations are decoupled in separate two-dimensional calculations of the electromagnetic and electrostatic fields around the track. The summed stored and dissipated energies in the fields for common and differential excitation modes enable independent calculation of the self and mutual impedances and admittances