A novel predicted current control scheme of BLDCMs for commutation torque ripple reduction

Commutation torque ripple of BLDCMs is still the main problem of the precise application. This paper presents a simple predicted the current control scheme of BLDCMs(Brushless DC Motors) during commutation region to reduce commutation torque ripple. The proposed method uses a predicted current slope and variations during commutation region. To keep the constant torque of total torque, turn-on time of incoming phase is calculated using the estimated back E.M.F. function. The proper turn-on time to get the same current variation during commutation region is obtained by the predicted phase currents of the BLDCM based on the instantaneous voltage equation. For the precise prediction of the phase current, continuous back emf is estimated by the look-up table according to the rotor position and measured speed. The proposed control scheme is verified by the Matlab simulation with practical 1.2kW BLDCM model.