Zero-loss switching in DC-DC series resonant converters under discontinuous conduction mode

Abstract

Many thriving applications where isolation is required, such as traction and EV fast charging, implement solid-state transformers (SST). Half-cycle discontinuous-conduction-mode series resonant converters (HC-DCM-SRC) are suitable for these applications. The focus of this paper is to perform a comprehensive approach to HC-DCM-SRC and provide straight-forward requirements in order to ensure zero-loss switching (ZLS) of semiconductors. In addition, these requirements can be expressed as design boundaries for the transformer. Finally, the paper shows that, due to ZLS, silicon devices may have larger power capability than silicon-carbide switches. Therefore, IGBTs can be used instead of SiC MOSFETs, resulting in a significant cost reduction of the converter.