Harmonic analysis on various traction transformers in co-phase traction system

Traction loads are subjected to significant load changes and frequent voltage change of about 5%, which is usually unacceptable to the public electricity supply. This paper presents a comparative study of traction transformers such as Scott, YNvd, Leblanc and Impedance Matching Transformer for reducing the total harmonic distortion and thereby improving the power quality in a co-phase traction system. A dual converter with a compensator is employed together with special traction balanced transformers to reduce the harmonics, voltage unbalance, negative sequence current and reactive power problems. This scheme is implemented by using Matlab/Simulink R2009a software. The simulation results show that the performance of the Impedance Matching Transformer is better compared to other special traction transformers.