High Voltage DC Traction Power Supply for Urban Rail Transit

For urban rail transit (URT), high-voltage AC (HVAC) power is generally transmitted from main substation (MS) to traction substations (TS), and then TS utilizes transformers and diode rectifiers to convert AC power to DC traction power. However, the traditional traction power supply (TTPS) shows the limitations in braking energy waste, high rail potential and stray current, etc. So high-voltage DC traction power supply (HDTPS) is proposed in this paper for URT. Both configuration and principle of HDTPS are analyzed, which mainly includes DC main substation (DMS) and DC traction substation (DTS). Then, the comparisons between HDTPS and TTPS on braking energy utilization, rail potential and stray current mitigation are discussed in detail. Finally, the simulation model of HDTPS is built to verify the above theoretical analysis.