Analysis of Novel Single-Stage Isolated Cuk-derived Converter for 800-V Electric Vehicle Onboard Charger

Recently, some research and development efforts have focused on 800-V passenger electric vehicles due to their ability to accept high fast-charge power levels. These vehicles still require an on-board charger (OBC), since convenient and lowcost overnight charging from residential power supplies will be important for powering regular commutes. There are some new challenges involved with designing efficient and compact 800-V OBCs, as they must have a high voltage gain from the 120-V or 240-V AC input, they must have high efficiency across a wide range of output voltages, as the battery charges from low to high state-of-charge, and they will require some higher voltage devices which increases cost. Though some 800-V OBC designs have been presented in the literature, many have a high component count. This paper presents a novel single-stage isolated Cuk-based 800V OBC with a low number of components, simple structure, and straightforward control. The operational principle is discussed and detailed simulation results are provided. The simulation results validate the converter operation, and show a low THD (1.71%), near unity power factor, and peak efficiency of 97.5%.