High Efficiency Floating Four-Phase Interleaved Charge-Pump Bidirectional DC-DC Converter with Wide Buck/Boost Voltage Ratio

A novel floating four-phase interleaved charge-pump bidirectional dc-dc converter (F4P-ICPBDC) with wide buck/boost voltage ratio is proposed in this article. The interleaved structure is adopted to reduce the current ripple through the low-voltage side, and the floating structure is adopted to achieve the high voltage ratio. In addition, to achieve balance of the average inductor current within the full duty cycle range, an asymmetric duty limit control (ADLC) strategy has been implemented. Furthermore, the operating principle of the converter is analyzed. Finally, a 2-kW prototype is developed with SiC-MOSFETs, which verifies the wide buck/boost voltage ratio of this converter between the constant low-voltage side (72 V) and the variable high-voltage side (400-800 V). The maximum efficiencies of the converter are recorded as 98.5% in the buck mode and 97.6% in the boost mode, respectively. The experimental results validate the feasibility and the effectiveness of the proposed converter.