Department of Electrical Engineering, Southern Taiwan University 1 A Novel Starting Method of the Surface Permanent-Magnet BLDC Motors Without Position Sensor for Reciprocating Compressor Student: Hsin-Feng Tu Professor: Ming-Shyan Wang Date : Dec,24,2010 Kwang-Woon Lee, Dae-Kyong Kim, Byung-Taek Kim, and Byung-Il Kwon, Member, IEEE, IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 44, NO. 1, J ANUARY/FEBRUARY 2008

Department of Electrical Engineering, Southern Taiwan University 2 Outline  Abstract  Introduction  Sensorless Control Of The BLDC Motor  Starting Sequence Of Sensorless BLDC Motor Control For Reciprocating Compressor  Proposed Starting Method  Simulation And Experimental Results  Conclusion  References

Department of Electrical Engineering, Southern Taiwan University 3 Abstract This paper describes a new position sensorless starting met hod, prevent demagnetization of permanent magnet and vibrations due to pulsating currents during the starting period. The proposed method limits the motor currents during the starting period to lower than the demagnetization currents by doing commutation. The proposed method limits the motor currents during the starting period to lower than the demagnetization currents by doing commutation depending on the level of the measu red phase currents.

Department of Electrical Engineering, Southern Taiwan University 4 Introduction DURING the last decades, energy saving has been one of the important issues in home appliances. sensorless control method based on the detection of zero cros sing point (ZCP) of back-electromotive force (EMF) has bee n widely used for low-cost. The rotor position during the starting period can be obtained by using inductance variation in the case of interior permanent magnet (IPM) type machines.

Department of Electrical Engineering, Southern Taiwan University 5 Sensorless Control Of The BLDC Motor Fig. 1. Current, back-EMF, and torque waveforms of the BLDC motor.

Department of Electrical Engineering, Southern Taiwan University 6 Sensorless Control Of The BLDC Motor

Department of Electrical Engineering, Southern Taiwan University 7 Sensorless Control Of The BLDC Motor Fig. 2. (a) Configuration of a BLDC motor drive

Department of Electrical Engineering, Southern Taiwan University 8 Sensorless Control Of The BLDC Motor Fig. 3. (b) Switching pattern

Department of Electrical Engineering, Southern Taiwan University 9 Sensorless Control Of The BLDC Motor Fig. 4. (c) terminal voltage sensing circuit

Department of Electrical Engineering, Southern Taiwan University 10 Sensorless Control Of The BLDC Motor Fig. 5. (d) terminal voltage waveforms

Department of Electrical Engineering, Southern Taiwan University 11 Starting Sequence Of Sensorless BLDC Motor Control For Reciprocating Compressor Fig. 6. Configuration of a refrigerator

Department of Electrical Engineering, Southern Taiwan University 12 Starting Sequence Of Sensorless BLDC Mot or Control For Reciprocating Compressor Fig. 7. Conventional startup sequence of a BLDC motor-driven reciprocating compressor

Department of Electrical Engineering, Southern Taiwan University 13 Starting Sequence Of Sensorless BLDC Mot or Control For Reciprocating Compressor Fig. 8. Experimental results on the irreversible demagnetization level of the used SPM-type BLDC motor with ferrite magnet

Department of Electrical Engineering, Southern Taiwan University 14 Proposed Starting Method Fig. 9. Current waveforms as the relation of the rotor position and the commutation point proper commutation lagged commutation leaded commutation

Department of Electrical Engineering, Southern Taiwan University 15 Proposed Starting Method Fig. 10. Relation of the average current (TH) and overcurrent value (TH_over)

Department of Electrical Engineering, Southern Taiwan University 16 Proposed Starting Method Fig. 11. Flowchart of the proposed starting method.

Department of Electrical Engineering, Southern Taiwan University 17 Proposed Starting Method

Department of Electrical Engineering, Southern Taiwan University 18 Simulation And Experimental Results Fig. 12. Simulation results of the conventional starting method

Department of Electrical Engineering, Southern Taiwan University 19 Simulation And Experimental Results Fig. 13. Simulation results of the proposed starting method

Department of Electrical Engineering, Southern Taiwan University 20 Simulation And Experimental Results Fig. 14. Simulation results of the proposed starting method with 10[%] variation of the back-EMF constant

Department of Electrical Engineering, Southern Taiwan University 21 Simulation And Experimental Results Fig. 15. Experimental test bed

Department of Electrical Engineering, Southern Taiwan University 22 Simulation And Experimental Results Fig. 16. Starting current waveforms at 0 kgf/cm2 pressure difference between the suction and the discharge port of the compressor. (a) Conventional method (b) Proposed method.

Department of Electrical Engineering, Southern Taiwan University 23 Simulation And Experimental Results Fig. 17. Starting current waveforms at 3.0 kgf/cm2 pressure difference between the suction and the discharge port of the compressor. (a) Conventionalmethod. (b) Proposed method

Department of Electrical Engineering, Southern Taiwan University 24 Simulation And Experimental Results Fig. 18. Starting current waveforms of the conventional method at 3.5 kgf/cm2 pressure difference between the suction and the discharge port of the compressor

Department of Electrical Engineering, Southern Taiwan University 25 Simulation And Experimental Results Fig. 19. Level of peak current at vibration. (a) Peak current. (b) Peak vibration measured at the compressor

Department of Electrical Engineering, Southern Taiwan University 26 CONCLUSION The experimental test of irreversible demagnetization was performed to obtain the irreversible demagnetization level of the BLDC reciprocating compressor when peak current is applied. The proposed method makes possible home appliances usi ng the BLDC motor, such as the refrigerator and the air conditioner, to obtain good performance.

Department of Electrical Engineering, Southern Taiwan University 27 References [1] K. Iizuka, H. Uzuhashi, M. Kano, T. Endo, K. Mohri, “Microcomputercontrol for sensorless brushless motor,” IEEE Trans. Ind. Appl., vol. IA-21, no. 3, pp. 595–601, May [2] N. Ertugrul and P. Acarnley, “A new algorithm for sensorless operation of permanent magnet motors,” IEEE Trans. Ind. Appl., vol. 30, no. 1, pp. 126–133, Jan./Feb [3] R. C. Becerra, T. M. Jahns, and M. Ehsani, “Four-quadrant sensorless brushless ECM drive,” in Proc. IEEE Appl. Power Electron. Conf. Expo., Mar. 1991, pp. 202–209. [4] S. Ogasawara and H. Akagi, “An approach to position sensorless drive for brushless DC motors,” IEEE Trans. Ind. Appl., vol. 27, no. 5, pp. 928–933. [5] J. P. Johanson, M. Ehsani, and Y. Guzelgunler, “Review of sensorless methods for brushless DC,” in Proc. IEEE IAS Conf., Oct. 1999, vol. 1,pp. 143–150. [6] D.-K. Kim, K.-W. Lee, and B.-I. Kwon, “Torque ripple reduction method in a sensorless drive for the BLDC motor,” KIEE Int. Trans. EMECS, vol. 4-B, no. 4, pp. 196–200, 2004.

Department of Electrical Engineering, Southern Taiwan University 28 References [7] D.-K. Kim, K.-W. Lee, and B.-I. Kwon, “Commutation torque ripple reduction in a position sensorless brushless DCmotor drive,” IEEE Trans. Power Electron., vol. 21, no. 6, pp. 1762–1768, Nov [8] M. Schroedl, “An Improved position estimation for sensorless controller permanent magnet synchronous motor,” in Proc. EPE Conf. Rec., 1991, pp. 418–423. [9] K.-Y. Cho, “Sensorless control for a PM synchronous motor in a single piston rotary compressor,” J. Power Electron., vol. 6, no. 1, pp. 29–37, Jan [10] G. H. Jang, J. H. Park, and J. H. Chang, “Position detection and start-up algorithm of a rotor in a sensorless BLDC motor utilizing inductance variation,” in Proc. Inst. Elect. Eng. Elect. Power Appl., vol. 149, no. 2, pp. 137–142, [11] Microlinear Corporation, “Position detection for a brushless dc motor,” U.S. Patent , San Jose, CA, [12] B.-J. Brunsbach, G. Henneberger, and Th. Klepsch, “Position controlled permanent magnet excited synchronous motor without mechanical Sensors,” Proc. Inst. Elect. Eng. Conf. Power Electron. Appl., vol. 6, pp. 38– 43, Sep [13] S.-C. Yoon and J.-M. Kim, “Sensorless control of a PMSM at low speeds using high frequency voltage injection,” J. Power Electron., vol. 5, no. 1, pp. 11–19, Jan [14] G.-H. Kang, J.-P. Hang, G.-T. Kim, and J.-W. Park, “Improved pa rameters modeling of interior permanent magnet synchronous motor b y finite element analysis,” IEEE Trans. Magn., vol. 36, no. 4, pp –1870, Jul

Department of Electrical Engineering, Southern Taiwan University 29 References [13] S.-C. Yoon and J.-M. Kim, “Sensorless control of a PMSM at low speeds using high frequency voltage injection,” J. Power Electron., vol. 5, no. 1, pp. 11–19, Jan [14] G.-H. Kang, J.-P. Hang, G.-T. Kim, and J.-W. Park, “Improved parameters modeling of interior permanent magnet synchronous motor by finite element analysis,” IEEE Trans. Magn., vol. 36, no. 4, pp. 1867–1870, Jul

Department of Electrical Engineering, Southern Taiwan University 30 Thanks for your attention!