A Power Flow Optimization Method for Urban Rail Flexible Traction Power Supply System Considering Train Dwell Time

The introduction of flexible traction power supply system can promote the mass utilization ratio of train regenerative braking energy, but the utilization is still insufficient. The unused part will be sent back to the urban distribution network through the converter in main substation, thus affecting its power supply quality. To solve them, this paper propones a power flow optimization tactic for urban rail transit flexible traction power supply system considering train dwell time. Firstly, the principle and law of regenerative braking energy utilization in flexible system are introduced, and the feasibility and necessity of further using this part of energy are analyzed. Secondly, the energy-economizing optimal model of urban rail multiple trains is established, and the system power flow optimization scheme considering train dwell time is designed based on PSO algorithm. Finally, based on real data of a domestic subway line, the validness of the scheme is supported by simulation. The simulation results indicate that the total energy expenditure of the optimized power supply system is reduced by 1.91%, and the energy saving efficiency is high, which has great practical value.