Modified magnetic equivalent circuit of double-stator single-rotor axial flux permanent magnet machine considering stator radial-end flux-leakage

A modified non-linear magnetic equivalent circuit (MEC) model is presented for double-stator single-rotor axial flux permanent magnet (AFPM) (DSSR-AFPM) machine considering stator radial-end flux-leakage, which is severer under a heavier load. Compared to the conventional MEC model for DSSR-AFPM machine, the proposed model can predict the electromagnetic performance more accurately when the machine operates under a heavy load. The proposed MEC model is verified by the finite element analysis (FEA) on a 24-slot/20-pole DSSR-AFPM machine. The comparison results show that the relative error between the proposed MEC model and FEA is <4% for back electromotive force and <5% for average electromagnetic torque, respectively. Specifically, the relative error of the average torque for the modified MEC model is 4.92% at 28.30 Arms/mm(2 )slot current density, which is lower than the conventional MEC model, that is, 7.75%.