Subdomain Model for Predicting Magnetic Field in Slotted Surface Mounted Permanent-Magnet Machines With Rotor Eccentricity

An analytical subdomain model for the prediction of open-circuit magnetic field in slotted surface-mounted permanent-magnet machines is developed in this paper, which considers the effect of rotor eccentricity. The magnetic field domain is divided into three types of simple and regular subdomains, viz. magnet, air gap, and stator slots. The analytical solution is derived by solving the field governing equations in each subdomain and applying the boundary conditions to the interfaces between these subdomains. The perturbation method is used to describe the effect of rotor eccentricity. The model accurately accounts for the effect of stator slots, the mutual influence between slots, and rotor eccentricity. The analytical model is validated by the corresponding finite-element results. The results show that the proposed subdomain model up to the first-order perturbation can accurately predict the open-circuit magnetic field in slotted surface-mounted permanent-magnet machines with rotor eccentricity.

[1]  Z. Zhu,et al.  An Accurate Subdomain Model for Magnetic Field Computation in Slotted Surface-Mounted Permanent-Magnet Machines , 2010, IEEE Transactions on Magnetics.

[2]  C. Espanet,et al.  Analytical Solution of the Magnetic Field in Permanent-Magnet Motors Taking Into Account Slotting Effect: No-Load Vector Potential and Flux Density Calculation , 2009, IEEE Transactions on Magnetics.

[3]  Z.J. Liu,et al.  Effect of Radial Magnetic Forces in Permanent Magnet Motors With Rotor Eccentricity , 2007, IEEE Transactions on Magnetics.

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

[5]  Quan Jiang,et al.  An improved analytical solution for predicting magnetic forces in permanent magnet motors , 2008 .

[6]  M. Hsieh,et al.  Unbalanced Magnet Pull in Large Brushless Rare-Earth Permanent Magnet Motors With Rotor Eccentricity , 2009, IEEE Transactions on Magnetics.

[7]  Z. Q. Zhu,et al.  Comparison of analytical models for predicting cogging torque in surface-mounted PM machines , 2010, The XIX International Conference on Electrical Machines - ICEM 2010.

[8]  M Popescu,et al.  Subdomain Model for Predicting Armature Reaction Field of Surface-Mounted Permanent-Magnet Machines Accounting for Tooth-Tips , 2011, IEEE Transactions on Magnetics.

[9]  Nady Boules.  Prediction of No-Load Flux Density Distribution in Permanent Magnet Machines , 1985, IEEE Transactions on Industry Applications.

[10]  Mircea Popescu,et al.  Unbalanced Magnetic Pull Due to Asymmetry and Low-Level Static Rotor Eccentricity in Fractional-Slot Brushless Permanent-Magnet Motors With Surface-Magnet and Consequent-Pole Rotors , 2010, IEEE Transactions on Magnetics.

[11]  Z.J. Liu,et al.  Accurate Prediction of Magnetic Field and Magnetic Forces in Permanent Magnet Motors Using an Analytical Solution , 2008, IEEE Transactions on Energy Conversion.

[12]  S. Mezani,et al.  2-D Exact Analytical Model for Surface-Mounted Permanent-Magnet Motors With Semi-Closed Slots , 2011, IEEE Transactions on Magnetics.

[13]  Zhejie Liu,et al.  Prediction and analysis of magnetic forces in permanent magnet brushless dc motor with rotor eccentricity , 2006 .

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

[15]  T Korakianitis,et al.  Analytical Magnetic Field Distribution of Slotless Brushless Machines With Inset Permanent Magnets , 2011, IEEE Transactions on Magnetics.

[16]  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.

[17]  U. Kim,et al.  Magnetic field calculation in permanent magnet motors with rotor eccentricity: without slotting effect , 1998 .

[18]  Z.J. Liu,et al.  Analytical Solution of Air-Gap Field in Permanent-Magnet Motors Taking Into Account the Effect of Pole Transition Over Slots , 2007, IEEE Transactions on Magnetics.

[19]  J. Hull,et al.  Magnetomechanics of internal-dipole, Halbach-array motor/generators , 2000 .

[20]  D. Staton,et al.  An Improved Subdomain Model for Predicting Magnetic Field of Surface-Mounted Permanent Magnet Machines Accounting for Tooth-Tips , 2011, IEEE Transactions on Magnetics.

[21]  D. K. Lieu,et al.  Magnetic field calculation in permanent magnet motors with rotor eccentricity: with slotting effect considered , 1998 .