1. Department of Electrical Engineering Southern Taiwan University Robot and Servo Drive Lab. Dynamic Performance of Brushless DC Motors With Unbalanced Hall Sensors Adviser ： Ming-Shyan Wang Student ： Hung-Lin Huang 2015/10/31 IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 23, NO. 3, page752~763 SEPTEMBER 2008 Nikolay Samoylenko, Student Member, IEEE, Qiang Han, Student Member, IEEE, and Juri Jatskevich, Senior Member, IEEE 製作率 :100%

2. Department of Electrical Engineering Southern Taiwan University Outline Abstract Introduction Permanent Magnet BLDC Machine Model Filtering Hall Signals Reference Switching Time Implementation and Case Studies Conclusion References 2015/10/31 Robot and Servo Drive Lab. 2

3. Department of Electrical Engineering Southern Taiwan University Abstract The Hall sensors in the BLDCM are ideally placed 120 electrical degrees apart. But most of the BLDC motor's hall sensors are unbalanced lead to unbalanced operation of the inverter and motor phases. The misplaced Hall sensors which increases the low-frequency harmonics in torque ripple and degrades the overall drive performance. This paper also presents some average-filtering methods that can be applied to the original Hall-sensor signals to reduce the effect of unbalanced placement during transient and steady- state. 2015/10/31 Robot and Servo Drive Lab. 3

4. Department of Electrical Engineering Southern Taiwan University Introduction(2/2) We propose a simple but very effective and practical filtering technique to improve the overall performance of a BLDC motor-drive system with significant unbalance in Hall-sensor positioning. This paper generalizes the approach of filtering the Hall-sensor signals and provides the experimental results. The methodology does not require any additional circuitry or hardware. This solution can be implemented motor controller, and therefore, may be useful for many applications. 2015/10/31 Robot and Servo Drive Lab. 4

5. Department of Electrical Engineering Southern Taiwan University BLDC drive system with filtering of Hall-sensor signals 2015/10/31 Robot and Servo Drive Lab. 5

6. Department of Electrical Engineering Southern Taiwan University BLDC Machine Model H{1,2,3}  actual Hall sensors H{1,2,3} ’  ideal Hall sensors ϕ A, ϕ B, ϕ C  error degrees 2015/10/31 Robot and Servo Drive Lab. 6

7. Department of Electrical Engineering Southern Taiwan University BLDC Machine Model Stator voltage equation Stator flux linkages 2015/10/31 Robot and Servo Drive Lab. 7

8. Department of Electrical Engineering Southern Taiwan University BLDC Machine Model Electromagnetic torque 2015/10/31 Robot and Servo Drive Lab. 8

9. Department of Electrical Engineering Southern Taiwan University BLDC Machine Model Stator phase currents. Speed = 2458 rpm Steady-state operating condition 2015/10/31 Robot and Servo Drive Lab. 9

10. Department of Electrical Engineering Southern Taiwan University BLDC Machine Model Electromagnetic torque waveforms. 2015/10/31 Robot and Servo Drive Lab. 10

11. Department of Electrical Engineering Southern Taiwan University BLDC Machine Model Electromagnetic torque harmonic content. 2015/10/31 Robot and Servo Drive Lab. 11

12. Department of Electrical Engineering Southern Taiwan University Filtering Hall Signals 2015/10/31 Robot and Servo Drive Lab. 12 360° 120°

13. Department of Electrical Engineering Southern Taiwan University Filtering Hall Signals 2015/10/31 Robot and Servo Drive Lab. 13

14. Department of Electrical Engineering Southern Taiwan University Filtering Hall Signals A. Basic Average Filters  suppressed and radians/sample 1) six-step filter 2) three-step filter 2015/10/31 Robot and Servo Drive Lab. 14

15. Department of Electrical Engineering Southern Taiwan University Filtering Hall Signals B. Extrapolating Filters (linear extrapolation) 2015/10/31 Robot and Servo Drive Lab. 15

16. Department of Electrical Engineering Southern Taiwan University Filtering Hall Signals B. Extrapolating Filters (quadratic extrapolation) 2015/10/31 Robot and Servo Drive Lab. 16

17. Department of Electrical Engineering Southern Taiwan University Filtering Hall Signals C. Performance of Filters (Magnitude and phase responses of different filters) 2015/10/31 Robot and Servo Drive Lab. 17

18. Department of Electrical Engineering Southern Taiwan University Filtering Hall Signals C. Performance of Filters (Response of different filters to a ramp increase in speed) 2015/10/31 Robot and Servo Drive Lab. 18 5 ms

19. Department of Electrical Engineering Southern Taiwan University Reference Switching Time The actual timing for commutating as follows: is the reference switching time may be the 2015/10/31 Robot and Servo Drive Lab. 19

20. Department of Electrical Engineering Southern Taiwan University Reference Switching Time The reference switching time “ * ”  Phase A, B, or C 2015/10/31 Robot and Servo Drive Lab. 20

21. Department of Electrical Engineering Southern Taiwan University Implementation and Case Studies C. Voltage-Step Transient No loads steps up from 20V to 35V Using three- and six-step averaging filters 2015/10/31 Robot and Servo Drive Lab. 21

22. Department of Electrical Engineering Southern Taiwan University Implementation and Case Studies C. Voltage-Step Transient No loads steps up from 20V to 35V Using extrapolating averaging filters 2015/10/31 Robot and Servo Drive Lab. 22

23. Department of Electrical Engineering Southern Taiwan University Implementation and Case Studies C. Voltage-Step Transient Basic moving-average filters Extrapolating filters 2015/10/31 Robot and Servo Drive Lab. 23

24. Department of Electrical Engineering Southern Taiwan University Conclusion This paper presented the phenomenon from low-precision BLDC motors with unbalanced Hall-sensor. Several filters have been proposed to improve the performance of BLDC motors. Using extrapolating and averaging filters will be the useful method to improve the low-precision BLDC motors ’ performance. 2015/10/31 Robot and Servo Drive Lab. 24

25. Department of Electrical Engineering Southern Taiwan University References [1] P. C. Krause, O. Wasynczuk, and S. D. Sudhoff, Analysis of Electric Machinery and Drive Systems. Piscataway, NJ: IEEE Press, 2002. [2] S. D. Sudhoff and P. C. Krause, “ Average-value model of the brushless dc 120 ◦ inverter system, ” IEEE Trans. Energy Convers., vol. 5, no. 3, pp. 553 – 557, Sep. 1990. [3] S. D. Sudhoff and P. C. Krause, “ Operation modes of the brushless dc motor with a 120 ◦ inverter, ” IEEE Trans. Energy Convers., vol. 5, no. 3, pp. 558 – 564, Sep. 1990. [4] P. L. Chapman, S. D. Sudhoff, and C. A. Whitcomb, “ Multiple reference frame analysis of non-sinusoidal brushless dc drives, ” IEEE Trans. Energy Convers., vol. 14, no. 3, pp. 440 – 446, Sep. 1999. [5] P. Pillay and R. Krishnan, “ Modeling, simulation, and analysis of permanent-magnet motor drives. Part II. The brushless dc motor drive, ” IEEE Trans. Ind. Appl., vol. 25, no. 2, pp. 274 – 279, Mar. – Apr. 1989. [6] W. Brown, “ Brushless dc motor control made easy ”, Microchip Technology,Inc., 2002 [Online]. Available: www.microchip.com. [7] P.B.Beccue, S. D. Pekarek, B. J. Deken, andA.C.Koenig, “ Compensation for asymmetries and misalignment in a Hall-effect position observer used in PMSM torque-ripple control, ” IEEE Trans. Ind. Appl., vol. 43, no. 2, pp. 560 – 570, Mar. – Apr. 2007. [8] C. Zwyssig, S. D. Round, and J. W. Kolar, “ Power electronics interface for a 100 W, 500000 rpm gas turbine portable power unit, ” in Proc. IEEE Appl. Power Electron. Conf., 19 – 23 Mar., 2006, pp. 283 – 289. [9] N. Samoylenko,Q.Han, and J. Jatskevich, “ Balancing hall-effect signals in low-precision brushless dc motors, ” in Proc. IEEE Appl. Power Electron. Conf., Anaheim, CA, Feb. – 28 Mar.2007, pp. 606 – 611. [10] N. Samoylenko, Q. Han, and J. Jatskevich, “ Improving dynamic performance of low-precision brushless dc motors with unbalanced Hall sensors, ” in Proc. IEEE Power Eng. Soc. General Meeting, Panel Session — Intell. Motor Control I, Tampa, FL, Jun. 24 – 282007, pp. 1 – 8. [11] Simulink: Dynamic System Simulation for MATLAB, Using Simulink Version 6, The MathWorks Inc., 2006. [12] Automated State Model Generator (ASMG), Reference Manual Version 2. West Lafayette, IN: P. C. Krause & Associates, Inc., 2003 [Online]. Available: www.pcka.com. [13] D. Shmilovitz, “ On the definition of total harmonic distortion and its effect on measurement interpretation, ” IEEE Trans. Power Del., vol. 20, no. 1, pp. 526 – 528, Jan. 2005. [14] M. Brackley and C. Pollock, “ Analysis and reduction of acoustic noise from a brushless dc drive, ” IEEE Trans. Ind. Appl., vol. 36, no. 3, pp. 772 – 777, May/Jun. 2000. [15] A. Hartman and W. Lorimer, “ Undriven vibrations in brushless dc Motors, ” IEEE Trans. Magn., vol. 37, no. 2, pp. 789 – 792, May 2001. [16] T. Yoon, “ Magnetically induced vibration in a permanent-magnet brushless dc motor with symmetric pole-slot configuration, ” IEEE Trans. Magn., vol. 41, no. 6, pp. 2173 – 2179, Jun. 2005. [17] J. G. Proakis and D. G. Manolakis, Digital Signal Processing. Upper Saddle River, NJ: Prentice-Hall, 1996, p. 248. [18] PIC18F2331/2431/4331/4431 Data Sheet, 28/40/44-Pin Enhanced Flash Microcontrollers with nano Watt Technology, High Performance PWM and A/D. Microchip Technology Inc., 2003 [Online]. Available: www.microchip.com. [19] Padmaraja Yedamale “ Brushless DC Motor Control Using PIC18FXX31 MCUs,AN899, ” Microchip Technology Inc [Online]. Available: http://ww1.microchip.com/downloads/en/AppNotes/00899a.pdf, 2008. 2015/10/31 Robot and Servo Drive Lab. 25

26. Department of Electrical Engineering Southern Taiwan University Thanks for your listening. 2015/10/31 Robot and Servo Drive Lab. 26