Department of Electrical Engineering Southern Taiwan University Robot and Servo Drive Lab. 2015/9/9 A Novel Four-Level Converter and Instantaneous Switching Angle Detector for High Speed SRM Drive Dong-Hee Lee and Jin-Woo Ahn, Senior Member, IEEE IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 22, NO. 5, SEPTEMBER Adviser:Ming-Shyan Wang Student:Wei-Cheng Huang Student ID: MA PPT 製作率 :100%

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 2 Outline Abstract Introduction Characteristics of high speed SRM Proposed speed controller Simulation and experimental results Conclusion References

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 3 Abstract A novel four-level converter and instantaneous switching angle detector for a high speed switched reluctance motor are proposed. Since the excitation time is very short compared to the general speed range of a high speed drive, the excitation current can not be built-up sufficiently. Also, The demagnetization current can be easily extended to the negative torque region.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 4 Abstract In addition, an instantaneous switching angle detector separated by main digital controller is designed for precise switching angle control. During high speed operation, rotor position error increases due to the constant sampling period of digital controller. The proposed instantaneous switching angle detector operates with optical encoder’s pulse and pre-set switching position regardless of sampling time.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 5 Introduction The proposed four-level converter has an additional charge capacitor and an active power switch compared to the conventional asymmetric converter. The charged high voltage of the additional capacitor is applied to the phase winding in excitation mode for the fast current buildup. The demagnetization phase current is quickly decreased due to the recharging of capacitor in the demagnetization mode.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 6 Introduction During high speed operation, rotor position error is increased due to the constant sampling period of the digital controller. The proposed instantaneous switching angle detector operates with an optical encoder pulse and pre-set switching position regardless of sampling time. The proposed high speed control system is verified by computer simulation and experimental results.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 7 Characteristics of high speed SRM Fig. 1. Asymmetric bridge converter and operating modes. (a) SRM drive using asymmetric converter. (b) Operating modes of asymmetric converter.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 8 Characteristics of high speed SRM Fig. 2. Current buildup in a high speed region.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 9 Characteristics of high speed SRM In order to secure enough time to buildup the desired phase current, the advance angle can be adjusted according to motor speed. From the voltage equations of the SRM, the proper advance angle can be calculated by the current rising time as follows regardless of phase resistance at the turnon position: where denotes the desired phase current of current controller and is the terminal voltage of each phase winding. The advance angle is determined by motor speed and (1) as follows: As speed increases, the advance angle is increased and turnon position may be advanced in to the negative torque region of the previous phase. (1) (2)

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 10 Characteristics of high speed SRM If the actual terminal voltage is assumed as dc link value,, the actual maximum phase current can be obtained when the advance angle is the previous unaligned position Where denotes the maximum advance angle from the previous unaligned position to, and is the minimum inductance at the unaligned position. And the maximum output torque of SRM at can be derived as follows: (3) (4)

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 11 Characteristics of high speed SRM Fig. 4. Excitation current according to switching position error. The maximum turnon and turnoff position error is assumed as follows: Where denotes the sampling period of the digital controller.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 12 Characteristics of high speed SRM Fig. 5. Torque error according to sampling time and speed.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 13 Proposed speed controller Fig. 8. Phase voltage and current of four-level converter.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 14 Simulation and experimental results

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 15 Simulation and experimental results Fig. 11. Comparison of current waveform ( rpm).

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 16 Simulation and experimental results Fig. 12. Comparison of speed response ( rpm).

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 17 Conclusion Fig. 17. Speed step response of asymmetric converter and proposed converter ( rpm). (a) Asymmetric converter. (b) Proposed four-level converter.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 18 Conclusion Fig. 18. Comparison of drive efficiency.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 19 References [1] W. L. Soong, G. B. Kliman, R. N. Johnson, R. A. White, and J. E. Miller, “Novel high speed induction motor for a commercial Centrifugal compressor,” in Proc. IEEE IAS Annu. Meeting, Oct. 1999, vol. 1, pp. 494–501. [2] M. A. Rahman, A. Chiba, and T. Fukao, “Super high speed electrical machines-summary,” in Proc. IEEE Power Eng. Soc. General Meeting, Jun. 2004, vol. 2, pp. 1272–1275. [3] B. H. Bae, S. K. Sul, J. H. Kwon, and J. S. Shin, “Implementation of sensorless vector control for super-high speed PMSM of turbo-compressor,” in Proc. IEEE Ind. Appl. Conf., Oct. 2001, vol. 2, pp. 1203–1209. [4] J. F. Pan, N. C. Cheung, W. C. Gan, and S. W. Zhao, “A Novel planar switched reluctance motor for industrial applications,” IEEE Trans. Magnetics, vol. 42, no. 10, pp. 2836–283, Oct [5] K. Ohyama, M. Naguib, F. Nashed, K. Aso, H. Fujii, and H. Uehara, “Design using finite element analysis of a switched reluctance motor for electric vehicle,” J. Power Electron., vol. 6, no. 2, pp. 163–171, Apr [6] Y. H.Yoon, Y. C. Kim, S. H. Song, and C. Y.Won, “Control of C-dump converters fed from switched reluctance motors on an automotive application,” J. Power Electron., vol. 5, no. 2, pp. 120–128, Apr [7] M. Krishnamurthy, C. S. Edrington, A. Emadi, P. Asadi, M. Ehsani, and B. Fahimi, “Making the case for applications of switched reluctance motor technology in automotive products,” IEEE Trans. Power Electron., vol. 21, no. 3, pp. 659–675, May [8] J.-W. Ahn, S.-J. Park, and D.-H. Lee, “Novel encoder for switching angle control of SRM,” IEEE Trans. Ind. Electron., vol. 53, no. 3, pp. 848–853, Jun [9] R. Krishnan, D. Blanding, A. Bhanot, A. M. Staley, and N. S. Lobo, “High reliabilitySRMdrive system for aerospace applications,” in Proc. Ind. Electron. Soc. (IECON’03),Nov. 2003, vol. 2, pp. 1110–1115. [10] J. Liang, D. H. Lee, and J. W. Ahn, “A novel four-level converter and instantaneous switching angle detector for high speed SR drive,” in Proc. IEEE Power Electron. Spec. Conf., Jun. 2006, pp. 1478–1483.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 20 References [11] V. P. Vujicic, S. N. Vukosavic, and M. B. Jovanovic, “Asymmetrical switched reluctance motor for a wide constant power range,” IEEE Trans. Energy Conv., vol. 21, no. 1, pp. 44–51, Mar [12] M. Dahmane, F. M. Tabar, and F. M. Sargos, “An adapted converter for switched reluctance motor/generator for high speed applications,” in Proc. IEEE Ind. Appl. Conf., Oct. 2000, vol. 3, pp. 1547–1554. [13] S. K. Mondal, S. N. Bhadra, and S. N. Saxena, “Application of currentsource converter for use of SRM drive in transportation area,” in Proc. Power Electron. Drive Syst. Conf., May 1997, vol. 2, pp. 708–713.

Department of Electrical Engineering Southern Taiwan University 2015/9/9 Robot and Servo Drive Lab. 21 Thank you for your listening!