Analysis of cogging torque reduction by increasing magnet edge inset in radial flux permanent magnet brushless DC motor

Abstract

Radial flux PMBLDC motors are designed using CAD program. CAD program gives dimensions and performance of the motor and compared with finite element analysis result to validate the design. Radial flux PMBLDC motor having only one major disadvantage that is cogging torque. Cogging torque cause due to interaction between magnet and stator teeth that lead to noise and vibration in motor. In this paper cogging torque is reduced by implementing magnet edge inset technique on three standard rating motors. It is inset of the ends of the magnet from the sleeve in millimeters. By increasing magnet edge inset in 70 W / 24 V, 2.2 kW / 230 V and 20 kW / 230 V reduces cogging torque respectively.