An EV Integrated Bidirectional DC Fast Charger based on a Dual Wound Synchronous Machine

Abstract

An electric vehicle (EV) drivetrain-integrated DC fast charger is presented that leverages per-phase magnetizing flux cancellation within a dual-wound, wound-rotor synchronous machine. Each 3-phase winding is fed by an inverter with a dedicated DC link capacitor. During driving mode, both inverter DC links are supplied by the EV battery, but while charging, one DC link is configured to serve as an external input port, capable of bidirectional energy transfer. The proposed charger allows charging the vehicle battery from similar or dissimilar DC voltages in either buck or boost modes. The proposed charger allows fault-tolerant operation without generating electromechanical torque inside the machine. Experimental validation has been provided, demonstrating a charging with equal DC voltages, buck, and boost mode.