1. Student: Tai-Rong Lai PPT製作率:100% Professor: Ming-Shyan Wang
Assessing pulse-width modulation techniques for brushless dc motor drives
BY YEN-SHIN LAI & YONG-KAI LIN IEEE INDUSTRY APPLICATIONS MAGAZINE ∙SEPT j OCT 2008 ∙ WWW. IEEE.ORG/IAS pp34-44.
Student: Tai-Rong Lai
PPT製作率:100%
Professor: Ming-Shyan Wang
2017/4/25

2. Robot and Servo Drive Lab.
Outline
Abstract
PWM techniques for BLDCM Drive
Driver Circuit
Reversal dc-Link Current
Circulating Current of Floating Phase
Back EMF Detection
Assessment of PWM Techniques—Theoretical Analysis and Experimental Confirmation
Conclusions
References
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Robot and Servo Drive Lab.

3. Abstract
The aim of this article is to assess the PWM techniques for BLDCM drives.
• Driver circuit
• Reversal dc-link current
• Circulating current of floating phase
• Back-EMF

4. PWM techniques for BLDCM Drive

5. PWM techniques for BLDCM Drive

6. PWM techniques for BLDCM Drive

7. Driver Circuit Photocoupler driver Isolated transformer driver
Bootstrap driver

8. Photocoupler driver

9. Isolated transformer driver

10. Bootstrap driver

11. Driver Circuit

12. Reversal dc-Link Current
CH1:chopper CH2:Vu CH3:Iu CH4:Idc

13. Reversal dc-link current, phase U

14. Circulating Current of Floating Phase

15. Circulating Current of Floating Phase

16. Back EMF Detection
Vp:denotes the terminal voltage for the phase connected to the positive dc-link rail during PWM control period.
Vn indicates the terminal voltage for the phase connected to the negative dc-link rail.
Vo is the terminal voltage for the floating phase.

17. Back EMF Detection

18. Assessment of PWM Techniques—Theoretical Analysis and Experimental Confirmation
Block diagram of the sensorless experimental system

19. Motor specifications Number of poles=8 Rated power=70W V dc= 24 V
Rated speed=2,500 rpm

20. CH1: high-side control, CH2: low-side control, CH3: terminal voltage
CH4: phase current, duty = 20%.

21. CH1: high-side control, CH2: low-side control, CH3: terminal voltage
CH4: phase current, duty = 80%.

22. CH1: high-side control, CH2: low-side control, CH3: terminal voltage
CH4: dc-link current, duty = 20%.

23. CH1: high-side control, CH2: low-side control, CH3: terminal voltage
CH4: dc-link current, duty = 80%.

24. CH1: terminal voltage
CH2: phase current, duty = 80%.
No load

26. Conclusions
The aim of this article is to assess the special features of five PWM techniques for BLDCM control. As shown here, the indexes include reversal dc-link current, circulating current, driver circuit, and back-EMF detection. Theoretical analysis is presented and followed by the experimental results. An inverter-controlled BLDCM drive without using any hall sensor and current sensor is set up. Experimental results fully support the analysis. These results provide the whole picture for applications reference.

27. References
[1] Seiko Epson Corp., ‘‘Brushless dc motor without position sensor and its controller,’’ E.P. Patent B1, 1993.
[2] Tokyo Shibaura Electric Co., ‘‘Inverter and air conditioner controlled by the same,’’ U.S. Patent , 1996.
[3] ST Microelectronics, ‘‘Control of a brushless motor,’’ U.S. Patent , 1999.
[4] J. Shao, D. Nolan, M. Teissier, and D. Swanson, ‘‘A novel microcontroller-based sensorless brushless dc (BLDC) motor drive for automotive fuel pumps,’’ IEEE Trans. Ind. Appl., vol. 39, pp. 1734–1740, Nov./Dec
[5] G. J. Su and J. W. McKeever, ‘‘Low-cost sensorless control of brushless dc motors with improved speed range,’’ IEEE Trans. Ind. Applicat., vol. 19, pp. 296–303, Mar
[6] R. C. Becerra, T. M. Jahns, and M. Ehsani, ‘‘Four-quadrant sensorless brushless ECM drive,’’ in Proc. 6th Annu. Applied Power Electronics Conf. Exposition, Mar. 1991, pp. 202–209.

28. References
[7] S. Ogasawara and H. Akagi, ‘‘An approach to position sensorless drive for brushless dc motors,’’ IEEE Trans. Ind. Applicat., vol. 27, pp. 928–933, Sept./Oct
[8] Y. S. Lai, F. S. Shyu, and Y. H. Chang, ‘‘Novel loss reduction pulsewidth modulation technique for brushless dc motor drives fed by MOSFET inverter,’’ IEEE Trans. Power Electron., vol. 19, no. 6, pp. 1646–1656, 2004.
[9] Y. S. Lai, F. S. Shyu, and Y. H. Chang, ‘‘Novel pulse-width modulation technique with loss reduction for small power brushless dc motor drives,’’ in Conf. Rec. IEEE IAS Annu. Meeting, 2002, pp. 2057–2064.
[10] Tokyo Shibaura Electric Co., ‘‘Drive control apparatus for brushless dc motor and driving method therefore,’’ U.S. Patent , 1996.
[11] Y. S. Lai, F. S. Shyu, and Y. K. Lin, ‘‘Novel PWM technique without causing reversal dc-link current for brushless dc motor drives with bootstrap driver,’’ in Conf. Rec. IEEE IAS Annu. Meeting, 2005, pp. 2182–2188.
[12] Y. S. Lai and Y. K. Lin, ‘‘A unified approach to back-EMF detection for brushless dc motor drives without current and Hall sensor,’’ in Proc. IEEE IECON, Nov. 2006, pp. 1293–1298.

29. References
[13] L6385: High-Voltage High and Low Side Driver, ST Microelectronics Datasheet, USA, 1999.
[14] J. T. Strydom, M. A. De Rooij, and J. D. Van Wyk, ‘‘A comparison of fundamental gate-driver topologies for high frequency applications,’’ in Proc. IEEE APEC, 2004, vol. 2. pp. 1045–1052.
[15] S. D. Sudhoff and P. C. Krause, ‘‘Operating modes of the brushless dc motor with a 120 inverter,’’ IEEE Trans. Energy Conversion, vol. 5, no. 3, pp. 558–564, 1990.

30. Robot and Servo Drive Lab.
Thanks for your listening ！
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Robot and Servo Drive Lab.