Novel System-Level Driving-Cycle-Oriented Design Co-Optimization of Electrical Machines for Electrical Vehicles

This paper presents a novel system-level design approach for optimizing electric vehicle (EV) traction motors. The technique tackles limitations of traditional finite element analysis software and allows for optimizing the entire electrical machine, power electronics, and control strategy design across a complete drive-cycle instead of a single operating point. Using the Worldwide Harmonized Light Vehicles Test Procedure (WLTP) as a benchmark, the proposed co-optimization technique is applied to an Electrically Excited Synchronous Machine (EESM) to maximize drive-cycle efficiency. In addition, Dynamic Motor Drive (DMD) strategy is applied to address the mismatch issue between typical EV operation and electrical machine efficiency zones to further reduce the power loss. Analytical results reveal that the optimized EESM system, when using DMD, exhibits superior torque, power, and drive-cycle efficiency compared to a commercial benchmark Interior Permanent Magnet (IPM) motor.