A T ORQUE R IPPLE C OMPENSATION T ECHNIQUE FOR A L OW -C OST B RUSHLESS DC M OTOR D RIVE H. K. Samitha Ransara and Udaya K. Madawala, Senior Member, IEEE 報告學生：蔡秉旂 指導教授：龔應時 教授 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 62, NO. 10, OCTOBER 2015

O UTLINE ABSTRACT INTRODUCTION MATHEMATICAL MODEL COMPENSATING FOR THE TORQUE RIPPLE IMPLEMENTATION RESULTS CONCLUSION REFERENCES

A BSTRACT Torque ripple compensation technique for a brushless dc (BLDC) motor drive that is operated without a DC link capacitor. The motor drive, which uses a single-switch control strategy, resembles that of a buck converter during operation at any switching state. Theoretical behavior of the BLDC motor drive is compared with MATLAB/Simulink-based simulations to demonstrate the validity of the compensation technique and the analysis. Experimental results of a 250 W prototype motor drive are also presented to further validate the theoretical analysis.

I NTRODUCTION Fig.1. (a) Typical BLDC motor drive.

Fig.1. (b) BLDC motor drive without a DC link capacitor. I NTRODUCTION

MATHEMATICAL MODEL Fig. 5. Controllable and uncontrollable regions of current of the motor drive at steady state.

MATHEMATICAL MODEL

COMPENSATING FOR THE TORQUE RIPPLE Fig. 6. Proposed technique for torque ripple compensation.

COMPENSATING FOR THE TORQUE RIPPLE COST COMPARISON BETWEEN THE CONVENTIONAL CONVERTER AND THE PROPOSED COMPENSATION TECHNIQUE

IMPLEMENTATION

RESULTS Fig.8. Case 1 with M1 for E = 95 V. (a) v in( t ) and E. (b) im ( t ) by theoretical analysis. (c) im ( t ) by simulation. (d) im ( t ) by experiment.

RESULTS Fig. 9. Case 2 with M2 for E = 80 V. (a) v in( t ) and E. (b) im ( t ) by theoretical analysis. (c) im ( t ) by simulation. (d) im ( t ) by experiment.

RESULTS Fig. 10. Case 3 with M1 for E = 65 V. (a) v in( t ) and E. (b) im ( t ) by theoretical analysis. (c) im ( t ) by simulation. (d) im ( t ) by experiment.

RESULTS Fig. 11. Comparison between the comprehensive model and the simple model. (a) Case 1 with M1. (b) Case 2 with M2. (c) Case 3 with M1.

RESULTS Fig.13. Proposed compensation for case 1.(a) Simulated im(t) without a capacitor and with a 150 μF capacitor. (b) Simulated im(t) with the proposed compensation. (c) Experimental im(t). (d) DC link voltage with the proposed compensation.

RESULTS Fig.14. Proposed compensation for case 3.(a) Simulated im ( t ) without a capacitor and with a 150 μ F capacitor. (b) Simulated im ( t ) with the proposed compensation. (c) Experimental im ( t ). (d) DC link voltage with the proposed compensation.

RESULTS Fig. 15. Torque–speed curves without a DC link capacitor, with a 150 μ F DC link capacitor and with the proposed compensation for M1.

CONCLUSION With the proposed technique for compensating torque ripples, comparable performance to a conventional BLDC motor drive with a large DC link capacitor can be achieved. However, with the torque ripple compensation technique, the overall complexity of the motor drive has been increased, which is a major disadvantage. The good agreement between the theoretical results, simulated results, and experimental results demonstrate the accuracy of the simple buck model and the effectiveness of the proposed compensation technique.

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