A frequency domain model for 3 kV DC traction DC-side resonance identification

Frequency-dependent effects in railway traction power systems arise from the impedance of substation and locomotive line filters and the traction line. Harmonic noise from traction drives and substations can excite resonances and produce overcurrent or overvoltage conditions at critical points in the network. In this paper, the harmonic feeding impedances of a 3 kV DC traction system seen from the rectifier substation, locomotive drive converter and pantograph terminals are presented. Several substation and locomotive filters are considered with a frequency-dependent traction line. Resonances attributed to the substation filter, locomotive filter and traction line are separate and distinct, the line introducing poles and zeros in the audio frequency (AF) range which vary in frequency and magnitude with locomotive position