A Bidirectional Charger for Low-Voltage-Powered Battery Vehicles

Abstract

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. Lastly, a comparison of the modified SEPIC with its counterparts, based on operational features, is made.