Comparison Analysis of Demagnetization and Torque Ripple in Accordance With Freewheeling Current in PM BLDC Motor

In this paper, we compared and analyzed the changes of demagnetization under fault condition and commutation torque ripple. Changes of freewheeling current (FC) are analyzed in accordance with speeds. Commutation torque ripple is analyzed in the FC section. In addition, change of demagnetization phenomenon is analyzed through change of flux density according to change of FC. Consequentially, we studied reliability and stability through changes of demagnetization and commutation torque ripple.