Analysis of a Three-Phase Four-Leg Front-End Converter for EV Chargers with Balanced and Unbalanced Grid Currents

This paper deals with a three-phase, four-leg, front-end converter for a double stage charger in electric vehicle (EV) applications. The considered topology is examined along with its operating principle. This front-end converter arrangement allows employing EV chargers as local, distributed power conditioner, while recharging EV battery. A three-reference frame, current controller has been implemented to deal with balanced and unbalanced ac-link currents, according to the smart grid demanding. The ac-current and dc-voltage ripples have been analyzed with regard to centered pulse-width modulation strategy. Analytical investigations have been verified by numerical simulations held in Matlab/Simulink environment