Power quality analysis in electric traction system with three-phase induction motors

• Interaction of electric power system and railway system.
• Modeling of electric traction system 25 kV, 50 Hz and the traction vehicle with 3f induction motors.
• Monitoring of power quality parameters at the point of electric railway system connection to transmission system.
• Measurements and analysis of power quality parameters.

Three-phase induction motors are widely used in electric traction systems. The impacts of the traction vehicles equipped with 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 three-phase induction motors on power quality in a 110 kV transmission network are investigated.The electric traction system 25 kV, 50 Hz and the traction vehicle with three-phase 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 consequently power quality parameters.Measurements and calculations 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.