Title :
Unbalanced magnetic forces in permanent magnet brushless machines with diametrically asymmetric phase windings
Author :
Ishak, D. ; Zhu, Z.Q. ; Howe, D.
Author_Institution :
Dept. of Electron. & Electr. Eng., Univ. of Sheffield, UK
Abstract :
A general analytical model, formulated in 2-D polar coordinates, is developed to predict the unbalanced magnetic force which results in permanent magnet brushless AC and DC machines having a diametrically asymmetric disposition of slots and phase windings. It is shown that the unbalanced magnetic force can be significant in machines having a fractional ratio of slot number to pole number, especially when the electric loading is high. The developed model is validated by finite element calculations on 9-slot/8-pole and 3-slot/2-pole machines.
Keywords :
brushless machines; finite element analysis; machine windings; permanent magnet machines; 2D polar coordinates; diametrically asymmetric disposition; diametrically asymmetric phase windings; electric loading; finite element calculations; permanent magnet brushless machines; pole number; slot number; unbalanced magnetic forces; Analytical models; Brushless machines; Finite element methods; Machine windings; Magnetic analysis; Magnetic forces; Permanent magnets; Rotors; Stators; Torque;
Conference_Titel :
Industry Applications Conference, 2005. Fourtieth IAS Annual Meeting. Conference Record of the 2005
Print_ISBN :
0-7803-9208-6
DOI :
10.1109/IAS.2005.1518484
