Systems such as photovoltaics (e.g., solar panels), electric vehicles, battery storage, and/or on-board charger for batteries can use bi-directional power converters. A bi-directional resonant converter can charge or discharge a storage battery from/to high voltage bus (e.g., four hundred volts). In a higher power application with a low voltage battery, the root-mean-square (RMS) current in the LC tank and bridge switches on the battery side can be very high. This high current presents a challenge, in terms of cost and efficiency, related to the selection of a resonant capacitor and the switches.
Moreover, in both bi-directional and uni-directional converters, another challenge is presented if the high voltage bridge switches are operating as rectifiers and using metal-oxide-semiconductor field-effect transistors (MOSFETs). For example, during discharge mode of a bi-directional converter, the switches on the bus side operate as rectifiers and are exposed to hard commutation (e.g., hard switching) of the antiparallel body diode. Hard commutation and the associated reverse recovery charge can induce high voltage spikes on the switches. Another example is that, for a uni-directional converter with high voltage output, hard commutation is a major concern if MOSFETs are used as synchronous rectifiers.