Partial Power DC-DC Converter with DC Short- circuit Fault Current Limiting Function for DC Fast Charging Station

As the power levels handled by EV DC fast chargers continue to increase, the loss of dc-dc converter during power conversion cannot be ignored. At the dc-dc stage, various partial power converters (PPC) have been proposed to reduce the power processed by the converter, thereby reducing losses and improving efficiency. On the other hand, the conventional partial power converter will inevitably brings high short circuit current. To solve the DC short-circuit fault problem of dc-dc converter, this paper proposes the topology of fault current limiting PPC. Based on a combination of coupling inductance and diode, the coupling inductance acts as a filter inductance when the PPC is running normally, and it has fault current limiting capability when a DC short circuit fault occurs. The proposed circuit topology and fault limiting capability are validated through numerical simulations.