Analysis on the unbalanced loop current of the traction power supply

摘要

Harassment traction loop current along the rail causes interference to track circuit of communication directly. With the increasing of train speed and capacity, the loop current becomes stronger and stronger, hence, conductive interference by unbalanced loop current is more serious. This paper analyzes electrified railway traction power supply and harmonic currents. Based on ZPW-2000A track circuit, mathematical model and simulation for unbalanced traction current harmonic interference are proposed and analyzed, via track four terminal network. Then onsite measurements and data fitting of the harmonic current frequency distribution and amplitude is drawn. Finally, reasonable suggestions on inhibition of track unbalance loop current and improve the anti-interference in the traction power supply system are proposed.