Isolated Semi Integrated On-board Charger for EVs Equipped with 6-phase Traction Drives

The recent trend in road transportation electrification pushes the development of reliable and compact solutions for the traction drives and charging infrastructures. This work proposes an innovative on-board battery charger partially integrated with the powertrain of a road electric vehicle equipped with a 6-phase traction motor drive. The integration permits to exploit the traction inverter and motor as power conversion unit and HF transformer respectively, with remarkable benefits in terms of e-axle compactness and cost of the components. Despite the integrated nature of the proposed system, galvanic isolation is provided, ensuring reliable and safe operation of the charger. Over to the traction drive, the proposed topology only requires a passive diode bridge and three grid inductors. A dedicated control strategy is developed to avoid torque production during charging. The proposal is validated by exhaustive simulations. A full experimental stage is currently ongoing, and promising preliminary results are reported.