Title :
New cogging-torque reduction method for brushless permanent-magnet motors
Author :
Koh, Chang Seop ; Seol, Jin-Soo
Author_Institution :
Sch. of Electr. & Comput. Eng., Chungbuk Nat. Univ., South Korea
Abstract :
We present a new design method for reducing cogging torque in brushless permanent-magnet (PM) motors. In our method, the auxiliary slots are put on the pole face of the magnetizing yoke, which results in a not fully magnetized zone (NFMZ) at the PM. Through Fourier expansion of the field and armature functions, the position and shape of the NFMZ that eliminate the cogging torque are found. In an example, we discuss the effectiveness and applicability of the new method.
Keywords :
brushless DC motors; finite element analysis; machine theory; machine windings; magnetic flux; permanent magnet motors; torque; Fourier expansion; armature functions; auxiliary slots; brushless permanent-magnet motors; cogging-torque reduction method; design method; field functions; finite-element calculation; harmonic components; magnetizing yoke; not fully magnetized zone; pole face; residual magnetic flux density; spectral analysis; torque ripple; winding slots; Brushless motors; Forging; Iron; Magnetic cores; Magnetic flux; Magnetic flux density; Magnetization; Permanent magnet motors; Shape; Torque;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2003.819473
