On Comparing Aluminum and Copper in Wound Field Synchronous Motors for Traction Applications

In the pursuit of electrifying transportation, rare-earth-free motors are at the forefront, reshaping the narrative of sustainable mobility. This paper explores the feasibility and sustainability of Wound Field Synchronous Motors (WFSMs) for heavy-duty trucks applications, as a replacement to the Interior Permanent Magnet (IPM) machine. The study assesses copper and aluminum solutions as potential winding materials for both the stator and rotor sides, aiming to minimize the environmental impact of the motor. Specifically, a WFSM rotor design optimization process is carried out for both solutions independently. Initially, they are compared based on the same torque output, and subsequently for similar rotor Joule losses. Ultimately, a comparison between the original IPM motor and the optimized Copper and Aluminum WFSM designs is conducted in terms of weight, cost, peak torque performance, efficiency, and gravimetric power density, providing a comprehensive assessment of the proposed solutions' potential.