A Cost-Effective Hybrid Si/SiC Dual Bridge Parallel <i>LLC</i> Resonant Converter for High-Current Application

The SiC-based dual bridge paralleled (DBP) LLC resonant converter offers advantages of low current stress and high efficiency but suffers from high costs. In this article, a cost-effective hybrid Si/SiC DBP LLC resonant converter is proposed, which consists of a high-current low-cost Si IGBTs bridge arm and a low-current SiC MOSFETs bridge arm, obtaining significant cost-reduction. Benefiting the soft-switching operation of the Si IGBTs bridge arm, the proposed hybrid Si/SiC DBP LLC converter can achieve comparable switching losses with full-SiC MOSFETs design. Meanwhile, fewer resonant tanks are required benefiting from the topology reconstruction of the proposed converter, in comparison to the prior-art design of DBP LLC resonant converter, further reducing costs and power loss. A 6-kW prototype of the hybrid DBP LLC resonant converter, utilizing both Si IGBTs and SiC MOSFETs, is constructed as a case study to validate the proposed approach. Compared to the prior art full-SiC DBP LLC converter, the proposed hybrid Si/SiC LLC converter achieves comparable total power loss under high output power, while offering 51.7% switching device cost, 22.9% resonant components cost, and 31.6% total cost reductions.