Analysis of electromagnetic processes in a homogeneous long line

Abstract

Dependences between the currents and voltages at terminals of a homogeneous long line were analyzed. They make it possible to more correctly explain the changes in current and voltage in an electric-traction network when switching the thyristor arms of a rectifier–inverter converter than do conclusions obtained during replacement of a long line with a circuit with lumped parameters. An imitation model of the homogeneous low-loss long line in the MATLAB/Simulink software environment is proposed that adequately represents the propagation of incident and reflected electromagnetic waves along the line. Transfer functions are presented that approximate the frequency dependences of the specific parameters of the equivalent rail–ground loop and the overhead catenary–ground loop calculated taking into account the increase in the resistance of the wires due to the eddy currents and the surface effect. The influence of frequency dependences of the specific electric parameters of an electric-traction network calculated by various methods on the free voltage oscillation decay on the electric locomotive pantograph obtained by modeling the electromagnetic processes in the traction substation–electric traction network–electric locomotive system is revealed.