Commutation Torque Ripple Reduction for Brushless DC Motor Based on an Auxiliary Step-Up Circuit

Xuliang Yao,Shengqi Huang,Jicheng Zhao,Jingfang Wang,Yishu Jiang

doi:10.1109/access.2019.2943411

Xuliang Yao, Shengqi Huang + Show 3 more

Open Access

https://doi.org/10.1109/access.2019.2943411

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Abstract

There exists torque ripple in the commutation process of brushless DC motor (BLDCM), which seriously restricts its application in the high-performance field. This paper proposes an auxiliary step-up circuit to suppress the commutation torque ripple of BLDCM, and the auxiliary step-up circuit consists of a transformer, a capacitor and a switch circuit. For effective suppression of the commutation torque ripple, the capacitor is charged in the non-commutation period. When the commutation occurs, the charged capacitor is added on the power source through a switch circuit to step up the dc-bus voltage in the commutation period, and the three-phase inverter is regulated to make the motor’s input voltage is equal to four times the back electromotive force (back EMF) amplitude. The auxiliary step-up circuit only transfers partial power required in the commutation process of the motor, and the capacity of the power components is reduced accordingly. The inductive energy stored in the transformer is returned to the power source in each switching cycle, which improves the energy utilization rate. In addition, this method can also shorten the commutation time. The validity and effectiveness of the proposed method is verified through experimental results.

Highlights

Brushless DC motor (BLDCM) is often one of the candidates for motion control due to the advantages of high efficiency, better reliability and lower maintenance cost [1], [2]
In [25], the dc-bus voltage is regulated by the power source in the non-commutation period and is switched to a single-ended primary inductor converter (SEPIC) in the commutation period
For effective suppression of the commutation toque ripple, the capacitor charged in the non-commutation period is connected in series with the power source to boost the dc-bus voltage, and the dc-bus voltage is regulated by the three-phase inverter to meet the input voltage requirement of the motor

Summary

INTRODUCTION

Brushless DC motor (BLDCM) is often one of the candidates for motion control due to the advantages of high efficiency, better reliability and lower maintenance cost [1], [2]. The commutation torque ripple generated in the high-speed range is effectively reduced with the suppression methods above, but the unfavorable commutation time is extended due to the fixed dc-bus voltage. In [25], the dc-bus voltage is regulated by the power source in the non-commutation period and is switched to a single-ended primary inductor converter (SEPIC) in the commutation period With this switching method, the torque ripple produced in the commutation period is effectively reduced. A suppression method based on an auxiliary step-up circuit is proposed to reduce the commutation torque ripple for BLDCM drive system. For effective suppression of the commutation toque ripple, the capacitor charged in the non-commutation period is connected in series with the power source to boost the dc-bus voltage, and the dc-bus voltage is regulated by the three-phase inverter to meet the input voltage requirement of the motor.

ANALYSIS OF COMMUTATION TORQUE RIPPLE

CAUSE OF COMMUTATION TORQUE RIPPLE

EXPERIMENT RESULT

Findings

CONCLUSION