Novel Bidirectional Single-Stage Isolated 600-V GaN M-BDS-Based Single-/Three-Phase-Operable EV On-Board Charger

Next generation On-Board Chargers (OBCs) should comprise only a single high-frequency-isolated ac-dc converter stage that realizes bidirectional power flow from not only a three-phase but also a single-phase grid to the Electric Vehicle (EV) battery and should cover a wide input-output voltage range. This paper introduces the novel isolated Y-Rectifier with series-resonant operation (iYRS), which utilizes 600 V GaN Monolithic Bidirectional Switches (M-BDSs) and complies with the aforementioned requirements for next-generation OBCs. The operating principles and control methods for buck-boost operation from a three-phase and a single-phase mains with the same rated power are detailed and validated by circuit simulations. The voltage and current stresses of the main power components are derived, and a 6.6kW design example indicates expected efficiencies of almost 97% for three-phase and 97.5% for single-phase operation.