A Hybrid Si/SiC Interleaved Bidirectional DC-DC Converter to Optimal Power Quality, Efficiency, and Cost Tradeoff

Abstract

The bidirectional dc-dc converters adopting silicon carbide (SiC) devices exhibit high efficiency and frequency performance benefit from the superior characterizes of the SiC devices but at the expense of significantly higher cost than Si-based converter at present. In this paper, a Si/SiC hybrid interleaved bidirectional dc-dc converter is proposed for optimal cost and performance tradeoff, in which a large current Si phase and a small current SiC phase is paralleled with different operating frequencies and unequal power distribution to deliver the near same benefits in high-frequency as a full SiC design. A simple strategy is proposed to match the unique operation principles and coordinate two phases operations. Experimental results on a 3kW 10kHz Si IGBT/100kHz SiC MOSFET bi-directional dc-dc converter are provided to validate the structure and exhibit a current spectrum up to 100kHz while achieving 98.1% peak efficiency and all above 97.5% across the entire load range.