Comparison Analysis of 18-Slot Stator in DSSR AFPM with Fractional Slot Concentrated Winding

This paper presents a comparative analysis of an 18-slot dual stator single rotor axial flux permanent magnet (DSSR AFPM) using fractional slots concentrated winding (FSCW), intended for electric vehicle (EV) propulsion systems. Four different pole configurations (12P, 14P, 16P, and 20P) are evaluated to determine their impact on key electromagnetic performance metrics. Using finite element method (FEM) simulations, the analysis focuses on back electromotive force (EMF) waveform quality, winding factor, torque output, cogging torque, and harmonic content. The results reveal that the 18S12P configuration achieves a higher winding factor and more sinusoidal back-EMF, making it suitable for sinusoidal control schemes, while the 18S16P and 18S20P configurations exhibit higher torque density but increased harmonic distortion. The findings provide valuable design guidelines for optimizing slot-pole combinations in AFPM motors, balancing torque performance, control smoothness, and manufacturability for high-efficiency EV propulsion applications.