Analytical Prediction of Cogging Torque for Spoke Type Permanent Magnet Machines

A generalized analytical field solution by conformal transformation is presented for calculation of no-load magnetic field distribution in the slot-less and slotted air gap of spoke-type permanent magnet (PM) machines. These analytical field solutions are used to predict the cogging torque of spoke-type PM motors. The computed cogging torque using the proposed method is compared with the results from 2D finite element analysis (FEA) in three application examples.

[1]  Xiuhe Wang,et al.  The optimization of pole arc coefficient to reduce cogging torque in surface-mounted permanent magnet motors , 2006, IEEE Transactions on Magnetics.

[2]  K. J. Binns,et al.  Analysis and computation of electric and magnetic field problems , 1973 .

[3]  Ali Keyhani,et al.  Analytical model for permanent magnet motors with surface mounted magnets , 2003 .

[4]  Z. Zhu,et al.  Instantaneous magnetic field distribution in brushless permanent magnet DC motors. III. Effect of stator slotting , 1993 .

[5]  P. Pillay,et al.  Cogging Torque Reduction in Permanent Magnet Machines , 2006, IEEE Transactions on Industry Applications.

[6]  T. Lipo,et al.  Analytical calculation of magnetic field distribution in the slotted air gap of a surface permanent-magnet motor using complex relative air-gap permeance , 2006, IEEE Transactions on Magnetics.

[7]  D. Howe,et al.  Analytical prediction of the cogging torque in radial-field permanent magnet brushless motors , 1992 .

[8]  T. Lipo,et al.  Analytical Solution for Cogging Torque in Surface Permanent-Magnet Motors Using Conformal Mapping , 2008, IEEE Transactions on Magnetics.

[9]  Leila Parsa,et al.  Interior Permanent Magnet Motors With Reduced Torque Pulsation , 2008, IEEE Transactions on Industrial Electronics.

[10]  Byung-Il Kwon,et al.  Rotor Pole Design in Spoke-Type Brushless DC Motor by Response Surface Method , 2007, IEEE Transactions on Magnetics.

[11]  Z. Zhu,et al.  Instantaneous magnetic field distribution in brushless permanent magnet DC motors. I. Open-circuit field , 1993 .

[12]  B. Kwon,et al.  A Study on Optimal Pole Design of Spoke-Type IPMSM With Concentrated Winding for Reducing the Torque Ripple by Experiment Design Method , 2009, IEEE Transactions on Magnetics.