Preliminary Evaluation of a Megawatt-Class Low-Speed Axial Flux PMSM With Self-Magnetization Function of the Armature Coils

This paper presents an axial flux permanent magnet synchronous machine (PMSM) with a disk rotor between two stators, which are wound in a tooth-coil technology (a concentrate winding type with subunitary number of slots/pole/phase). This type of winding facilitates the magnetizing inductor function of stator coils. A potential magnetizing system can be envisioned by taking into account that the coil span and the slot pitch are practically identical, the number of tooth-coils and poles are almost the same, and that there are two rotor poles between four tooth-coils (two adjacent tooth-coils on each stator). Thus, a special magnetizing inductor is not required in order to magnetize, pair by pair, the permanent magnet (PM) rotor poles. The number of tooth-coils exceeds the number of rotor poles by one (Ns = 2p + 1). Some aspects of the average performance obtained in both modes of operation-machine and magnetizing inductor-are highlighted by digital simulation. A scale-down demonstrating model also confirmed the feasibility of the magnetizing inductor function of the stator.

[1]  C. Sadarangani,et al.  Winding factors and Joule losses of permanent magnet machines with concentrated windings , 2003, IEEE International Electric Machines and Drives Conference, 2003. IEMDC'03..

[2]  W. H. Pickering.  Missiles, rockets, and space flight , 1959, Electrical Engineering.

[3]  P. Curiac,et al.  Prospects for magnetization of large PM rotors: conclusions from a development case study , 2003 .

[4]  Jacek F. Gieras,et al.  Permanent magnet motor technology : design and applications , 1996 .

[5]  K. Sitapati,et al.  Performance comparisons of radial and axial field, permanent magnet, brushless machines , 2000, Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129).

[6]  D. Howe,et al.  The design of radial-field multipole impulse magnetizing fixtures for isotropic NdFeB magnets , 1997 .

[7]  G. Huth.  Optimierung des Wicklungssystems bei permanentmagneterregten AC — Servomotoren , 1999 .

[8]  Don-Ha Hwang,et al.  An modular-type axial-flux permanent magnet synchronous generator for gearless wind power systems , 2004, 30th Annual Conference of IEEE Industrial Electronics Society, 2004. IECON 2004.

[9]  Thomas A. Lipo,et al.  Cogging torque minimization technique for multiple-rotor, axial-flux, surface-mounted-PM motors: alternating magnet pole-arcs in facing rotors , 2003, 38th IAS Annual Meeting on Conference Record of the Industry Applications Conference, 2003..

[10]  P. Curiac,et al.  Field pulse magnetization of power PMSM rotors , 2005 .

[11]  Pia Salminen,et al.  Fractional slot permanent magnet synchronous motors for low speed applications , 2004 .