A New BLDC Motor Drives Method Based on BUCK Converter for Torque Ripple Reduction Readymade Electrical Projects

2006, IEEE

ABSTRACT: 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



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.


[1] Joong-Ho Song and Ick Choy, “Commutation torque ripple reduction in brushless DC motor drives using a single DC current sensor,”IEEE Trans. on Power Electronics,vol. 19, No.2 ,pp.312-319,March 2004.

[2] Byoung-Hee Kang,Choel-Ju Kim,Hyung-Su Mok and Gyu-Ha Choe, “Analysis of torque ripple in BLDC motor with commutation time,”Proceedings of IEEE,vol.2,pp.1044-1048, June 2001.

[3] Carlson R,Lajoie-Mazenc M and Fagundes J.C.d.S, “Analysis of torque ripple due to phase communtation in brushless DC machines,”IEEE Trans. on Industry Applications,vol.28,no.3, pp.632-638,May-June 1992.

[4] Luk P.C.K and Lee C.K, “Efficient modeling for a brushless DC motor drive,”International Conference on Industrial Electronics,Control and Instrumentation,vol.1,pp.188-191, September 1994.

[5] Lei Hao,Toliyat,H.A, “BLDC motor full speed range operation including the flux-weakening region,”IEEE-IAS Annual Meeting,vol.1,pp.618-624, Octorber 2003.

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