Magnetic Equivalent Circuit for Multistage Axial Flux Surface Permanent Magnet Machines

Abstract

This article presents a magnetic equivalent circuit for the electromagnetic analysis of axial flux permanent magnet synchronous machines. The proposed methodology is based on a quasi-3D approach and incorporates the non-linear iron core behavior, the rotor motion, and magnetic leakage effects. A key strength of the proposed approach is its adaptability to different machine configurations, starting from a single-stage network and extended to multistage topologies with different stator-rotor arrangements. This article also provides a detailed guide to constructing the reluctance network, including simplifications to facilitate adoption by less experienced designers. Validation is performed against both three-dimensional (3-D) finite-element analysis simulations and experimental tests, demonstrating good agreement in key performance metrics, such as magnetic flux density, back electromotive force, and torque. The results validate the performance of the proposed magnetic equivalent circuit in reducing computational time while maintaining satisfactory accuracy, positioning it as a valuable tool for preliminary design and optimization of studies.