Analysis of Cogging Torque in Brushless Machines Having Nonuniformly Distributed Stator Slots and Stepped Rotor Magnets.

A simple analytical technique is proposed for synthesizing the cogging torque waveform of a permanent magnet brushless machine from the cogging torque waveform that is associated with a single stator slot. The machine may have either uniformly or nonuniformly distributed stator slots and/or a skewed rotor, in which the skew is realized by circumferentially displacing the magnets of each pole. The technique is validated by finite element analysis and measurements. [ABSTRACT FROM AUTHOR]