Performance Improvement of Permanent Magnet Brushless DC Motor through Cogging Torque Reduction Techniques

In a permanent magnet motor, the presence of cogging torque is the principal cause of torque ripple. It creates vibration and audible noise in the motor. Cogging torque can be decreased by adequate design modification in permanent magnet motor. This paper represents the cogging torque reduction by two different design modification techniques in radial-flux surface-mounted Permanent Magnet Brushless DC (PM BLDC) motor. A distinct combination of design techniques - changing magnet edge inset, and changing tooth gap angle are applied for BLDC motor rated 2.2 kW, 230 V, 1450 rpm. By Finite Element Analysis (FEA), the reduction of cogging torque has been performed with the aid of MotorSolve software. The simulation results indicate a reduction in cogging torque with negligible deviation in motor torque and back-emf.