Innovative SMC Insulation Technique Applied to Axial Flux Machine Prototypes

The paper describes in detail the realization of an axial flux machine prototype adopting an innovative Soft Magnetic Composite (SMC) material. The novel technique here presented regards a Layer-by-Layer deposition adopted to insulate pure iron powder grains previously selected. The obtained material is then used to prepare the machine's stator parts. The activity steps are detailed: from the powder preparation to the molding phase, the consequent milling for the final shape, and the consequent magnetic, energetic and mechanical characterization. The prototype design and assembly imply the realization of the stator with the adopted innovative material, and the Authors also realized the preparation of the rotor equipped with bonded magnets. The preliminary experimental results are presented at the end, and considering the machine to be the first trial with the presented material, the efficiency of 77% should be viewed as a promising result for the future development of the activity

AFPM Machines Equipped with Multilayer Magnets

This article investigates the manufacturability and applicability of unified multilayer magnets, comprising two different magnetic materials with distinct characteristics, for use in electrical machines. In particular, the self-produced multilayer magnets are made of compressed NdFeB bonded powders for the ‘strong’ magnet layer and hybrid composite materials for the ‘weak’ magnet layer. Various combinations of material for the self-produced permanent magnets are experimentally investigated. Also, the suitability of resultant multilayer bonded magnets to electrical machines is articulated on the basis of finite element simulations. To assess their performance, three axial-flux surface-mounted permanent magnet machines are constructed: one conventional machine with single-layer bonded magnets as the reference, and two machines equipped with multilayer magnets with series and parallel configurations. The performance of the machines are evaluated in terms of the back-EMF, output torque, torque ripple, losses, efficiency, and cost. The findings indicate an appreciable enhancement in flux-weakening operation for the machine equipped with multilayer magnets, but at the expense of lower flux linkage values and nominal torque. Further analyses of the multilayer magnet's trade-offs and potential applications in electrical machines are presented

Overview on bonded magnets realization, characterization and adoption in prototypes

5noIn the paper bonded magnets materials, their realization and adoption in electromechanical devices, are presented and evaluated. In particular the effects of different process parameters in their realization are deeply analyzed and described, supported by practical activities. Bonded magnets have been tested in various prototypes of rotating electrical machines and magnetic sensors; experimental results, comparing the performance of the devices equipped with these materials, with the original ones are presented. Furthermore a new magnetic material family is being explored, the Hybrid Magnetic Composites (HMC); they are prepared with both soft and hard magnetic powders, properly mixed with binders, and some examples of adoption in practical applications are proposed.reservedmixedPoskovic E.; Ferraris L.; Carosio F.; Franchini F.; Bianchi N.Poskovic, E.; Ferraris, L.; Carosio, F.; Franchini, F.; Bianchi, N