Research on the Topology of 750V Push-Pull DC/DC Converters for Railway Trains

In this paper, in order to meet the demand of reducing the 750 V high-voltage direct current obtained by the train from the traction network to low-voltage direct current and supplying power to the train’s DC load, a DC/DC converter with an input voltage of 750 V based on the working principle of the push-pull circuit is designed. The topology of this DC/DC converter utilizes series capacitor and adopts new switching devices and appropriate control logic, which simplifies the circuit topology and complexity of the control circuit while reducing the voltage stress of the switching devices. The working principle of the DC/DC converter is researched and the impact of high-frequency transformer leakage inductance on the working performance of the DC/DC converter is considered. A simulation model was built using Matlab/Simulink, demonstrating that the input and output of the converter meet the design requirements and the working process is consistent with theoretical analysis.