A Single Stage Off-board EV Charger Based on CUK Topology

A CUK topology based single stage single phase electric vehicle (EV) battery charger is introduced in this paper. The application area is commonly found EV three wheelers in Bangladesh and South East Asia. The converter simultaneously shapes the input AC current and controls the output charging DC current in a single stage with only a single control loop. No extra input filter is required. The topology is based on a single active switch CUK converter with low cost low frequency transformer. Complete analytical design process is explained. A small signal model and controller is developed for the charger. Converter design is verified through extensive simulations in PSIM. This converter is designed and tested for 48V/60V lead acid battery charging at approximately C/5 rate of around 12A. High power quality in terms of low THD and high power factor is achieved in the total operation range of the charger.