부산대학교 도서관

A battery charger with bidirectional operability for a low-voltage battery-powered vehicle is discussed in this work. A notable advantage of the presented charger is the effective performance with a wide output voltage range. Hence, this charger facilitates the user to charge a 48-V battery-powered vehicle as well as a 120-V battery-powered vehicle from a single-phase ac supply. Keeping this in view, the presented battery charger utilizes a modified single-ended primary inductor converter (SEPIC) as the back-end dc/dc converter. The modified-SEPIC has significantly improved bidirectional operation with a wide voltage ratio of the output voltage and the input voltage. Hence, it effectively regulates the battery current of both a 48-V battery-powered vehicle and a 120-V battery-powered vehicle. Unlike the conventional SEPIC, the modified-SEPIC utilizes switches with identical ratings. Thus, the manufacturing complexity reduces. Performance verification is carried out through the experimental analysis of the designed battery charger on a 1.1-kW hardware setup in the laboratory environment. The effectiveness of the battery charger is tested amid diverse operating conditions. Moreover, the conduct of the battery charger during the vehicle-to-grid (V2G) operation is discussed. Finally, a comparison of the modified-SEPIC with its counterparts, based on operational features, is made.