Comparison of flux weakening capability in alternative switched flux permanent magnet machines by mechanical adjusters

To extend the speed range in the switched flux permanent magnet (SFPM) machines, mechanically movable flux adjusters (FAs), which consist of iron pieces located outside the stator, are utilized to adjust the airgap flux density. A comparative study of conventional SFPM machines with different stator/rotor pole combinations, i.e. 12/10, 12/13 and 12/14, and the multi-tooth, E-core, and C-core SFPM machines, is presented with the objective of exploring the best machine topology to equip with the FAs. 2D finite element analysis (FEA) is employed to predict the electromagnetic performance of SFPM machines with emphasis on the flux-weakening capability. Compared with multi-tooth, E-core and C-core types of SFPM machines, the maximum speed can be significantly increased if the conventional SFPM machines are equipped with FAs. Moreover, the 12/13 and 12/14 SFPM machines with FAs may exhibit infinite speed range.

[1]  J. B. Wang,et al.  Mechanically adjusted variable-flux concept for switched-flux permanent-magnet machines , 2011, 2011 International Conference on Electrical Machines and Systems.

[2]  F. Crescimbini,et al.  Permanent-magnet, direct-drive, starter/alternator machine with weakened flux linkage for constant-power operation over extremely wide speed range , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[3]  Nobuyuki Matsui,et al.  High efficiency adjustable speed control of IPMSM with variable permanent magnet flux linkage , 1999, Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370).

[4]  Thomas A. Lipo,et al.  A PERMANENT MAGNET AC MACHINE STRUCTURE WITH TRUE FIELD WEAKENING CAPABILITY , 1996 .

[5]  O. Honorati,et al.  Ironless Axial Flux PM Machine With Active Mechanical Flux Weakening For Automotive Applications , 2006, Conference Record of the 2006 IEEE Industry Applications Conference Forty-First IAS Annual Meeting.

[6]  Kou Baoquan,et al.  A new flux weakening method of permanent magnet synchronous machine , 2005, 2005 International Conference on Electrical Machines and Systems.

[7]  Shigeo Morimoto,et al.  Advantages of IPMSM with adjustable PM armature flux linkage in efficiency improvement and operating range extension , 2002, Proceedings of the Power Conversion Conference-Osaka 2002 (Cat. No.02TH8579).

[8]  D. Howe,et al.  Analysis of electromagnetic performance of flux-switching permanent-magnet Machines by nonlinear adaptive lumped parameter magnetic circuit model , 2005, IEEE Transactions on Magnetics.

[9]  S. Kawamata,et al.  Development of variable magnetic flux motor suitable for electric vehicle , 2010, The 2010 International Power Electronics Conference - ECCE ASIA -.