Development of Non-Isolated Bidirectional Quadratic DC-DC Converter with Reduced Switch Current Stress

This paper introduces a bidirectional quadratic DC-DC converter designed to reduce voltage stress on capacitors and current stress on switches. The proposed converter achieves these reductions by incorporating an additional MOSFET and inductor on the Low Voltage (LV) side and by utilizing series capacitors to supply the High Voltage (HV) side. These modifications result in lower ratings for the LV side MOSFET and HV side capacitor, while also enhancing efficiency by reducing conduction loss in the LV side switches. The paper includes a steady-state analysis of the converter, along with equivalent circuits and analytical waveforms. The components are designed for a power rating of 200 W, a high voltage side of 400 V, a low voltage side of 48 V, and a switching frequency of 50 kHz. Experimental results obtained from a laboratory prototype are presented, and the performance is compared with several recently reported converters. Additionally, the proposed converter features a common ground between the input and output ports, contributing to reduced stress and improved efficiency.