Abstract :
In this paper analyses results of harmonic and resonance behavior of Tehran-Karaj electric railway are presented. This special electric traction system supplied by 225 kV Autotransformers (ATs) in the west side and a simple mode (without any return feeder) in the east side is considered here where the east side will be equipped with ATs in future development. Also, some parameters which can change quantity and extremity of resonance are explored. For harmonic analysis, Total Harmonic Distortion (THD) factor and Total Demand Distortion (TDD) factor are assessed. To detect the resonance points of the traction power system, harmonic frequency scans are applied. Harmonic analysis of the model is simulated by PSCAD/EMTDC software.