Railway lines models for impedance evaluation

This paper deals with modeling of electrified railway lines using the multiconductor transmission lines (MTLs) approach, in order to investigate the harmonic impedance seen at the train pantograph at various locations along the line. A railway line model has been studied and a sensitivity analysis with respect to the structure of the model has been performed in relation to a simple traction system. Different equivalent models with reduced number of conductors have been considered. Calculation results, obtained estimating the impedance at various locations as a function of the position along the line and for frequencies up to 6 kHz, are reported and widely described in the paper