Torque Ripple Reduction of BLDC motor using Predicted Current Control

This paper presents a simple predicted current control scheme for BLDC(Brushless DC) motor to reduce the torque ripple in the commutation and conduction region. In the proposed control scheme, the inverse function of back emf is used to consider the back emf characteristic in the conduction region. In the commutation region, a predicted current of incoming and outgoing phase are used to calculate the slope and variation of commutated current. The proper duty ratio to keep the constant current is supplied during commutate to reduce the torque ripple. This method is realized by the precise prediction of the phase current, continuous back emf by the look-up table according to the rotor position and measured speed. Finally, experiment is performed and the experiential results show that the proposed control scheme can well keep the constant torque during the conduction and commutation region.