Design of a Yokeless double disc axial flux motor for light electric vehicles

Abstract

One of the main challenges in designing electric vehicles is determining traction system performance, as engine power directly impacts battery size and the engine itself. Therefore, high power density, efficiency, and torque are all essential for vehicle autonomy and performance. This study proposes developing a dual-disc axial synchronous motor for Society of Automotive Engineers (SAE) Formula-type light vehicles. It addresses key motor design parameters such as current, terminal voltage, winding configuration, and reactances. The objective was to meet demands for specific vehicle dynamics, e.g., a wide RPM range, high torque, and dynamic performance. These parameters were validated using finite element simulations, which were then compared to a three-phase induction motor in a simulation software used by the Cheetah vehicle racing E-competition team. The motor designed here aims to provide superior dynamism, especially given the absence of reduction systems, which in turn reduces the losses associated with transmission ratios. This study not only details the dual-disc AFPM engine design process, but also validates it using finite element simulations, and presents justifications for improved dynamic performance and efficiency relative to an engine used in a Formula SAE competition. The side-by-side comparison clearly showed significant gains in speed, and significant reductions in lap time for the motor developed here.

Keywords

• Axial flux motor
• Double-disc
• Synchronous machine