Three-Phase On-Board Integrated Bidirectional EV Battery Charger with Power Factor Correction

This paper deals with an integrated on-board charger for an electric vehicle (EV) that integrates nine-phase traction motor and inverter already present in an electric vehicle for propulsion into the charging operation. This charger utilizes extra degrees of freedom available in the nine-phase machine to provide charging/vehicle to grid (V2G) operation without any torque generation. The charger is also capable of providing unity power factor (UPF) operation when it is connected to three-phase grid outlet and doesn't require any hardware rearrangement between charging/V2G and propulsion operation mode. Theoretical analysis is provided for symmetrical as well as asymmetrical nine-phase systems. Control strategy for charging and V2G operation is discussed. Finally theoretical concepts are justified by the appropriate simulations in both charging as well as V2G operation mode.