Power Quality Analysis in Electric Traction System with Three-phase Induction Motors

Three-phase induction motors are widely used in electric traction systems. Impacts of the traction vehicle equipped by three-phase induction motors on power quality are much different from the impacts of vehicles with DC traction motors. In this paper, the effects of the traction vehicle operation with threephase induction motors on power quality in 110 kV transmission network are investigated. The electric traction system 25 kV, 50 Hz and the traction vehicle with 3f induction motors were modeled including AC/DC rectifier and DC/AC inverter based on IGBT technology. The parameters of those power electronic elements directly determine the current and voltage waveforms and power quality parameters. Modeling, measurements and analysis of power quality parameters were presented. Three operation modes of traction vehicle were considered including acceleration, constant drive and regenerative breaking. During the test drives, the values of total harmonic distortion, unbalance, flicker and power factor were obtained.