Double Stator Axial Airgap Spoke-PMSM Performance Investigation for High Torque Density by 3D FEM with a Direct-Drive Powertrain Case Study

High torque density together with high Nm/watt of copper loss and Nm/kg of sintered PM are paramount in EV(HEV) applications. In general values in the range of 60-80 Nm/l, 8-12 Nm/kg (of active volume and weight) and current densities for peak torque up to 20 A/mm2 and 100-120 Nm/kg of PM are obtained in the main commercial EV of today. Going above 200 Nm/l and above 200 Nm/kg of sintered PM is now in the R&D trends but still only up to 17 Nm/kg (active weight) have been in general reported recently. Building on previous recent work, the authors extend it by investigating the performance of a dual-stator spoke-PM Axial Flux PMSM drive for EVs by 2D/3D FEM. In this paper more than 230 Nm/l, 28 Nm/kg of active weight and more than 280 Nm/kg of sintered PM is demonstrated by 3D FEM for a case study of a 24 slots/32 poles rotor with 276 mm stator core diameter and 50 mm long stator stack for a current density of 22 A/mm2•