Impact of Return Traction Current Harmonics on the Value of the Potential of the Rail Ground for the AC Power Supply System

The problem of the increased potential of the rail-ground with the flow of electric trains reverse traction current operating in the area of the AC feeder is considered. The studies were caused by the need to ensure the electrical safety of the staff and the infrastructure facilities reliability when passing trains of increased weight. In the process of experimental studies of the high potentials causes in rail circuits, data were obtained indicating the complex nature of the electromagnetic interaction of reverse current harmonics with rail circuits. For studies of electromagnetic compatibility between railway subsystems, it requires the use of simulation programs that help to reveal most critical conditions for electromagnetic compatibility conditions, and allow the evaluation of electromagnetic interference from rolling stock in rails in the worst conditions. A developed the traction current harmonics distribution model in the rails is considered in this paper. The traction current harmonics distribution in the rails was calculated for a direct AC power supply of 25 kV depending on the distance from the power supply substation, the conductivity of the railway and the ground and the number of trains in the feeder zone. The results of the harmonics distribution simulation are in satisfactory agreement with the experimental data and will allow the technical measures development to reduce the rail-ground potential.