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With the economy development of our country, the constant enlargement of the urban construction scale, many large and medium-sized urban rail transit planning and construction is booming. DC traction power supply system is an important part of the urban rail transit power supply system, the multi-pulse rectifier currently as the core technology of which has drawn greater attention, while the three-phase PWM rectifier with its superior performance, its application in DC traction power supply system newly become the hotspot for study of the scholars at home and abroad.In present paper, it is modeled and simulated for the 12-pulse, 24-pulse widely used in present DC power supply system, various operation mode of 12-pulse and 24-pulse rectifier are analyzed, simulation waveforms are given, parameters calculation method are shown. To simplify structure, but get performance as good as traditional 24-pulse, a 24-pulse rectifier with auxiliary circuit is proposed to use in urban rail transit traction power supply system, simulation results validate its feasibility and effectiveness.In view of the diode rectifiers are adopted in current urban rail transit, energy unable to flow bidirectionally, unit power factor could not be achieved, harmonic pollution is still exist, this paper study on applying high-power PWM converter in DC traction power supply system, predicted current control based on SVPWM model is built, both phase-shifting transformer-based and carrier phase-shifting based rectifier program are discussed, comparing the simulation results, it is conculed the later one is a relative simpler, superior scheme.Urban rail transit traction power supply system includes AC side, DC side and train, which is a time-varying, AC-DC hybrid system, in order to check the dynamic performance of the power supply, the simulation platform of 24-pulse power supply system based on the train drive system is built in this paper, validating 24-pulse power supply system performance and inspection the impact of train traction, braking and load for the current harmonics on AC side and voltage fluctuation on DC side.
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