A Wide Output Voltage Resonant EV Charger With Power Factor Correction

This paper presents a wide output voltage electric vehicle battery charger (EVBC) for two wheelers and small three wheelers with an improved power quality of input AC current. This EVBC is capable of charging an EV battery with different open circuit voltages, typically ranging from 48V to 72V. This EVBC consists of two converters, namely a front¬end power factor correction converter and a back-end isolated DC-DC converter. The front-end converter is a single ended primary inductance converter (SEPIC) converter with a voltage buck-boost capability and is operated in continuous inductor conduction mode (CICM) using a two loop structure. The back¬end DC-DC converter, is a pulse frequency modulated (PFM) half bridge resonant inductor-inductor-capacitor (HBLLC) converter with synchronous rectification at the output. This work uses the battery voltage and operating frequency of HBLLC converter to improve the efficiency of EV charger and support wide output voltage operation. A prototype of proposed EVBC is developed and its performance is validated for different batteries.