ELECTROMAGNETIC-FIELDS IN TRACTION SYSTEMS - MODELING AND APPLICATIONS

A two-dimensional electromagnetic field model of a railway track and t raction line is used to determine the equivalent track distributed tra nsmission line parameters in the frequency range DC to 30 kHz. The mod el is solved using the finite-element method to find the minimum energ y condition for two conditions: current excitation to obtain the resis tance and inductance, and voltage excitation for the conductance and c apacitance. The results have been confirmed using practical test data, and their application is illustrated in a time-domain circuit simulat ion to model interference between power and signalling currents in a 7 50V DC electric railway.