Identification and Analysis of Low-Frequency Cogging Torque Component in Permanent Magnet Machines

D. McIntosh
Sonsight Inc. / NSWC, Accokeek, MD, USA
Published in 2008

Cogging torque in permanent magnet motors and generators is characterized by a torque ripple. These torque fluctuations cause vibrations, noise and speed fluctuations. This paper presents finite element (FE) analyses results that show a previously unaddressed low frequency modulation of cogging torque ripple.

The paper resulted in an analytical formulation of cogging torque with low frequency modulation to provide a means of optimizing designs of permanent magnet motors. The formula has been validated by comparison to simulation results using the COMSOL Multiphysics AC/DC Module.

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