Effect of Armature Reaction and Skewing on the Performance of Radial-flux Permanent Magnet Brushless DC Motor

In this paper the effect of armature reaction and skewing on the performance of a 70 W, 24 V, 350-rpm surface mounted radial-flux permanent magnet brushless DC (PM BLDC) motor is presented. The net reduction in peak torque of the motor due the effect of armature reaction is only 2.8%. The rate of reduction in airgap flux density because of the armature reaction is 5.59 mT/A from no-load to full-load. The 2D Finite element (FE) results are exploited for the analysis of skewing. The percentage torque ripple is reduced from 24% to 13.63% and 7.07% for the half and full slot pitch skewing respectively.