Universal Bridgeless Onboard Battery Charger with Wide Output Voltage Range for e-Transportation

Electric vehicles (EVs) accommodate an inherent onboard charger (OBC) which provides instant charge to the batteries through available domestic outlets. The operating range of conventional OBCs is confined to step-up operation; however, EV power train voltages range from 120–450 V depending on the vehicle type and configuration. The existing wide voltage range OBCs are buck-boost derived and are realized with a front-end diode bridge configuration, resulting in a discontinuous input current, and increased conduction losses due to more devices in the conduction path. Furthermore, the control of OBCs using traditional controllers produces current transients during transition periods. This paper proposes a universal bridgeless isolated onboard battery charger with a wide output voltage range at a universal input power supply. A dual loop controller with a smooth transition logic is designed to accomplish a seamless transition during mode change instants. The effectiveness of the proposed 3.3 kW OBC is validated on the MATLAB/Simulink platform under various operating conditions.