Design and Analysis of Axial-Flux Modular Interior Permanent Magnet Machines with Yokeless and Segmented Armature

This paper proposes a novel axial-flux modular interior permanent magnet (MIPM) machine with the yokeless and segmented armature (YASA). The modeling was performed by coupling the magnet magnetomotive force (MMF) of PMs with the permeance of air-gap to predict the working harmonics. Then, the influence of rotor pole numbers on the electromagnetic performance of the proposed machine is analyzed in detail. Finally, a conventional YASA machine with surface-mounted PM (SPM) is compared to reveal the merits of the proposed machine in terms of PM eddy current loss and irreversible demagnetization using 3-D finite-element analysis (FEA).