This paper presents a comprehensive analysis on torque ripples of brushless dc motor drives in conduction region and commutation region. A novel method for reducing the torque ripple in brushless dc motors with a single current sensor has been proposed by adding BUCK converter in the front of 3-phase inverter.In such drives, torque ripple suppression technique is theoretically effective in commutation region as well as conduction region. Effectiveness and feasibility of the proposed control method is verified through experiments.
1. Brushless dc motor
2. Torque ripple
3. Conduction region
4. Commutation region
Fig1. The new proposed circuit configuration
EXPECTED SIMULATION RESULTS:
Fig.2. The 2-phase current-waveforms of conventional modulation mode
Fig.3. The 2-phase current-waveforms of new proposed modulation mode
Fig.4.The commutation current-waveforms of conventional modulation mode
Fig.5.The commutation current-waveforms of new proposed modulation mode
In this paper,a new torque ripple reduction method based on buck converter has been proposed for brushless dc motor drives using a single dc current sensor. In such control method, the dc-link current sensor can give correct information corresponding to the motor phase currents to eliminate torque ripples in conduction region. Meanwhile, torque ripples have been attenuated effectively during commutation region. Subsequently effectiveness and feasibility of the proposed control method are verified through experiments.
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