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 low-cost 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%.