A novel ZCS high step-up DC-DC converter for energy storage systems in DC traction vehicles

This paper proposes a new soft-switched High Step-up DC-DC converter for energy storage systems in DC traction vehicles. In this converter, soft-switching operation, i.e., zero current switching has been obtained by employing dual resonant auxiliary circuits to the conventional step-up DC-DC converter. The auxiliary resonant consists of additional auxiliary switches; inductor and capacitor are used to achieve soft-commutation especially when the main active switching devices are being turned-on to turned-off. The main active switching device of this converter achieves soft commutation with reduced voltage stresses and reduced switching losses. Firstly, the operation principles and its design analysis are discussed in detail. Finally, the simulation verification on an input with 100V and 350V/2kW converter system operated at 50kHz switching frequency to validate the theoretical expectations and its effectiveness