A Multifunctional Integrated Three-Level Inverter and On-Board Charger for Electric Vehicle Application

<div class="section abstract"><div class="htmlview paragraph">This paper presents a highly integrated 4-in-1 power electronics solution for 800V electric vehicle applications, combining on-board charging (OBC), DC boost charging, traction drive, and high-voltage/low-voltage (HV/LV) power conversion in a single housing. Integration is achieved through the use of motor windings for charging and a custom-designed three-port transformer that magnetically couples HV and LV batteries while ensuring galvanic isolation. The system also employs a three-phase open-ended winding machine (OEWM) to support both single-(1P) and three-phase (3P) AC charging. A dual-bank DC/DC architecture allows for seamless integration of a redundant auxiliary power module (APM), enhancing functional safety and autonomy. In AC charging mode, the three-level (3L) T-type inverter operates as a Vienna rectifier for 3P charging and as a totem-pole power factor correction (PFC) circuit for 1P charging, with the motor windings utilized as PFC inductors. In DC boost charging mode, the 3L inverter functions as a boost converter, stepping up the 400V DC input to the 800V battery. A triple active bridge (TAB) converter facilitates HV-to-HV and HV-to-LV DC/DC conversion and also functions as a Dual Active Bridge (DAB) during boost charging and traction modes. In traction mode, the T-type 3L inverter drives the motor. Finally, the system is benchmarked against conventional non-integrated designs, demonstrating significant improvements in cost, volume, and weight.</div></div>