High-Efficiency On-Board Chargers Using SiC and GaN Devices

This paper reviews recent advances in on-board chargers (OBCs) for electric vehicles (EVs) that leverage wide-bandgap (WBG) semiconductors silicon carbide (SiC) and gallium nitride (GaN) and presents a detailed design and analysis of a high-efficiency, compact OBC targeting 6.6 kW single-phase/three-phase operation with bidirectional capability. We compare SiC and GaN device tradeoffs, present suitable converter topologies, discuss gate-driver and EMI considerations, and provide a system-level co-design methodology to realize >97% peak efficiency and high power density. Example loss calculations, thermal management approach, and control strategy (including power factor correction and bidirectional control) are provided. The paper synthesizes recent literature and application guidance to provide a practical engineering roadmap for researchers and industry designer.