In this paper, we analyzed and compared changes of demagnetization under fault conditions and commutation torque
ripples in a PM BLDC motor. Changes of freewheeling current are analyzed at different speeds. Commutation torque ripple is
analyzed in the freewheeling current section.
Also, the change of demagnetization phenomenon is compared and analyzed through a change of flux density according to the
change of freewheeling current. Consequentially, we studied reliability and stability through changes of demagnetization and
commutation torque ripple.