Bidirectional Single-Phase Integrated On-Board Charger for Ultracapacitor-Battery Based EVs with V2G and Regenerative Braking Capability

This paper develops the EV powertrains by introducing a multiport multifunctional integrated charger designed for single-phase systems. As an integrated on-board charger, this system utilizes the stator windings of the Permanent Magnet Synchronous Motor (PMSM) as the rectifier filter. Four distinct winding configurations are employed to achieve torque cancellation during the charging mode. These configurations are elucidated and comprehensively compared in the paper. The innovative multiport structure of the DC-DC stage allows for the incorporation of ultracapacitors as supplementary power storage alongside the battery, thereby augmenting the performance of the hybrid powertrain during acceleration and regenerative braking. This integration makes it possible to extend the battery lifespan. To streamline the powertrain component count, the proposed charger is engineered to operate in five distinct modes: charging, acceleration, driving, regenerative braking, and Vehicle-to-Grid (V2G) functionality. The buck-boost operation of the DC-DC stage across all operational modes enables flexible voltage regulation for the DC-link, Ultracapacitor, and battery. This versatility facilitates optimized charging and discharging processes for both the battery and ultracapacitor, enhancing overall system efficiency. The proposed charger undergoes comprehensive analysis across all modes, with theoretical assessments meticulously validated through simulation results.