Interleaved Boost PFC with Half Bridge LLC Resonant Converter based EV Battery Charger

Electric scooters are attaining demand over conventional ICE scooters due to increases in fuel costs, depletion of fossil fuels, and reduced maintenance in EVs. This paper presents a 1kW two-stage onboard charger consisting of an interleaved boost PFC converter in the primary stage and a half-bridge LLC resonant converter at the secondary stage. The PFC stage maintains a voltage of 310V which is regulated to charge a 60V 86Ah electric scooter battery by the LLC resonant converter. The converter PFC stage is operated in discontinuous conduction mode to achieve natural power factor correction reduce the burden of implementation of complex control circuits and increase the reliability of the converter. The half-bridge topology in the secondary stage reduces the number of switches required without affecting the efficiency of the converter. The secondary stage converter is further operated in zero voltage switching mode to reduce the switching losses. The simulation results show that the system can perform satisfactorily achieving power factor correction and managing the THD level at acceptable limits for EV battery chargers.