Modeling, Design, Analysis, and Control of a Nonisolated Universal On-Board Battery Charger for Electric Transportation

On-board chargers (OBCs) in electric transportation resolve the anxiety for frequent charging of the battery packs. This paper presents a single-phase nonisolated OBC for electric transportation using a two-switch topology. The main advantage of this OBC is that it can perform high input power quality over a wide output voltage conversion range. The presented two-switch converter is able to operate with an output voltage above and below the peak of input voltages. The analysis and various operating modes of converter and design considerations to achieve the wide output voltages are discussed in this paper. Moreover, small-signal analysis of the converter in various modes to aid for the design of the controller is also presented. A two-mode control scheme with average current-mode (ACM) control structure using PI controllers is shown in this paper with a feature of automatic mode selection. As a proof of concept, the experimental results from a 1-kW laboratory prototype with an output voltage range of 150-450 V are presented. A high input power factor of 0.99 and an efficiency of 96% have been achieved from the prototype.