400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2003-01-0446 TF-Machines: An Illustration of the Magnetic Capabilities of the Powder Metallurgy Materials Ahmed Masmoudi University of Sfax Ahmed Elantably Allison Transmission Divi sion of General Motors Reprinted From: 42 Volt Technology 2003 (SP-1769) 2003 SAE World Congress Detroit, Michigan March 3-6, 2003Downloaded from SAE International by University of Minnesota, Monday, July 30, 2018All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise,without the prior written permission of SAE. For permission and licensing requests contact: SAE Permissions 400 Commonwealth DriveWarrendale, PA 15096-0001-USAEmail: [email protected]: 724-772-4028Tel: 724-772-4891 For multiple print copies contact: SAE Customer ServiceTel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-1615Email: Customer [email protected] ISSN 0148-7191Copyright © 2003 SAE International Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the pap er if it is publishe d in SAE Transactions. Persons wishing to submit papers to be considered for presentation or publication by SAE should send themanuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USADownloaded from SAE International by University of Minnesota, Monday, July 30, 20182003-01-0446 TF-Machines: An Illustration of the Magnetic Capabilities of the Po wder Metallurgy Materials Ahmed Masmoudi University of Sfax Ahmed Elantably Allison Transmission Division of General Motors Copyright © 2003 SAE International ABSTRACT Powder metallurgy materials, also termed soft magnetic composites (SMC), present features which are of greatimportance for the power production capabilities of thetransverse flux permanent magnet machine (TFPM). Thecommon characteristic of TFPMs is the 3D flux paththrough a magnetic circuit made up of a high number oflaminated U- or C-shaped cores in the stator, whilepermanent magnets are mounted in the rotor, generallyin a flux concentration arrangement. The 3D flux couldnot be achieved using lamination without considerableflux distortion yielding high iron losses. The substitutionof the laminated U- or C-shaped cores used in earlierTFPM concepts by SMC-made cylindrical toothed sets isbeing deeply investigated. The paper develops this idea. INTRODUCTION As has been highlighted since the middle of theeighteenths’, starting with the works of Weh [1], the transverse flux permanent magnet machine (TFPM)exhibits interesting characteristics. Especially its powerdensity which, up to date, is the highest compared tothose given by conventional and emerging converter-fedmachines. TFPMs have been found viable candidates forelectric and hybrid propulsion applications. Currently,many automotive manufacturers are involved in R&Dprojects focusing efficient and cost effective TFPMdesigns [2,3,4,5,6,7]. Most if not all TFPM topologies share the following features: 1. The plane of field is perpendicular to the direction of motion rather than in the plane of motion as in conventional machines. The flux flows through themagnetic circuit within three dimensional (3D) paths:radial, axial and circumferential directions2. The stator circuit is simply wound around toothed magnetic circuit in a circumferential concentratedring. Each turn of the ring winding links the flux ofevery pole in the phase. Giving the high number ofpoles in transverse flux machines, this leads tohigher torque densities 3. Compared to conventional machines, transverse flux machin