Cogging torque components appear at harmonics equal to
the number of magnets on the rotor and the number of teeth in
the stator as well as integer multiples of these numbers [6].
The motor used for this research is constructed with 20
magnets on the rotor and 24 slots/teeth on the stator. Cogging
torque contributes to the 20th and 24th harmonics for this
motor as well as at integer multiples. The dominant peak in
Figure 1 is the 48th harmonic which is a multiple of the 24th
and hence is due to cogging torque.