Loss-Minimizing Operation of Vehicle Powertrains with Front and Rear Electric Drive Units

Electric vehicles use electric drive units (EDUs) to develop forces required for propulsion and braking. This paper considers a powertrain architecture with one EDU on the front axle and a second clutched EDU on the rear axle. Within these EDUs are permanent-magnet synchronous machines and their current-regulating power converters. The goal is to command the clutch and power converters to produce a desired force at a specified speed while minimizing power loss, to maximize range. A model-based formulation of this optimization problem is presented, which allows investigation of how model parameter changes influence the optimization results. The merits of this approach are demonstrated symbolically and numerically.