Reduction of Cogging Torque in Surface Mounted Permanent Magnet Brushless DC Motor by Adapting Rotor Magnetic Displacement

Cogging torque is a critical dilemma in Permanent Magnet Brushless DC (PMBLDC) motors. In medium-low power PMBLDC motors, redundant vibrations and forbidding noises arise as result of the harmonic magnetic forces created by cogging torque. This paper introduces simple approach for minimizing motors applying placement irregularities rotor magnets. An angle shift magnets surface-mounted helps to attain magnet displacement. displacement imparts an asymmetrical structure rotor. Maintaining pole arc pitch ratio (L/?) between 0.6 0.8, shifting angles from 1° 8° were considered order analyze effect on analytical expression was also derived finding with minimum motor using Virtual Work Method (VWM). The optimization investigated 3D Finite Element Analysis (FEA). A comparison simulation results carried out. It determined that reduction showed good agreement FEA analysis.