Torque Ripple Reduction Technique Using Current Injection for a Five-Phase PM-BLDC Drive

Multiphase Permanent Magnet Brushless Direct Current (PM-BLDC) motor drives has a promising performance over other permanent magnet machines. The five phase PM-BLDC motor drive is commonly supplied by square wave current which increases torque ripples owing to the current deviation from its ideal shape during commutations. This paper suggests current supply strategies to reduce torque ripples through current injection in phases of the motor. The injecting current would be derived current vectors from the back emf and torque developed by the motor. It is observed that the current vectors have a flower petal shape trajectory on the plot of the stationary plane. Torque ripples developed by the motor are determined by the vector trajectory. Theoretical findings can be verified with the simulation results obtained using the PM-BLDC drive specifications used for aircraft applications.