Analytical Modeling an‎d Optimization of a Ring Winding Axial Flux Permanent Magnet Motor for Electric Vehicles

8/30/2026 12:00:00 AM

Abstract: In recent decades, the increasing capacity an‎d decreasing cost of batteries, coupled with the need to reduce vehicle-related pollution in urban environments, have brought electric vehicles into focus. This shift has placed electric motors, which serve as the core component of these vehicles, at the forefront of research an‎d development. Permanent magnet motors have emerged as a popular topology for electric vehicle applications. This dissertation investigates the Ring Winding Axial Flux Permanent Magnet (RWAFPM) motor, a recently introduced type of permanent magnet motor, for its potential in electric vehicle applications. The primary objective of this dissertation is to enhance an‎d optimize the RWAFPM motor for electric vehicle use. To achieve this, an analytical model based on the Schwartz-Christoffel mapping was developed, offering a reasonable balance of computational speed an‎d accuracy. This model is capable of predicting the motor’s performance parameters with satisfactory precision relative to its analysis speed. The model’s results were validated against finite element analysis, confirming its accuracy. High copper losses, excessive copper consumption, an‎d significant cogging torque are among the primary drawbacks of the RWAFPM motor. This dissertation proposes structural modifications to address these issues while preserving the motor’s fundamental characteristics, thereby improving performance an‎d reducing manufacturing costs. By stan‎dardizing the motor’s segments into a single type an‎d introducing a novel winding model, the number of motor components was reduced, leading to a 38% reduction in copper volume an‎d a 21.5% decrease in copper losses. Additionally, even-order harmonics resulting from segment asymmetry were eliminated. To isolate the effects of cooling in the optimization process, the 2010 Prius motor was selec‎ted as a benchmark for comparison. By imposing constraints to ensure equivalent copper, magnet, an‎d core material usage, as well as material types an‎d losses in both motors, the RWAFPM motor was optimized to maximize torque. The results demonstrate that the optimized motor achieves 85% of the torque output of the 2010 Prius motor, with the peak-to-peak cogging torque reduced from 35.2 Nm to 16 Nm. For a laboratory-scale motor compared to an industrial one, these results are considered promising. The finite element method was validated against experimental results an‎d served as the basis for comparison. Keywords: Electric vehicle, RWAFPM, Schwartz-Christoffel mapping, modeling, optimization

بهينه سازي , خودرو الكتريكي , RWAFPM , نگاشت شوارتز كريستوفل , مدل سازي

Optimization , Electric Vehicle , RWAFPM , Schwartz-Christoffel Mapping , Modeling

Mohammad Bapiri

Abolfazl Vahedi