Design and Analysis of In-wheel Flux Reversal Motor for Compact EV

This paper presents the design and analysis of cross-pole-shape flux reversal (FR) motors for compact electric vehicles (EVs). First, the optimal cross-pole width is investigated that 2.0° provides high torque, reduces eddy current losses in the magnets, and suppresses even-order harmonics in the no-load induced voltage. An 18/24-pole FR motor is then optimized using a genetic algorithm (GA). The results reveal that the optimized FR motor generates both reluctance and magnet torque due to its cross-poleshaped stator structure, leading to enhanced torque performance and a maximum torque of approximately 61 N·m. The performance of the optimized FR motor is compared to previously reported in-wheel switched reluctance (SR) motor. The FR motor produces higher torque across the entire operating range and maintains an efficiency above 90% over a wide region. Finally, driving performance is evaluated by applying the FR motor as an in-wheel motor in a compact EV. The results demonstrate excellent hillclimbing ability and a maximum speed of 55 km/h, which is 10 km/h faster than EV with SR motor-based EV.