本論文探討感應馬達之直接轉矩控制法，所產生轉矩漣波過大的現象，並實現一種以固定磁通變量之直接轉矩控制法，有效抑制轉矩漣波。
感應馬達之直接轉矩控制法有簡單、易於實現、且受參數變化影響不大的特性，但直接轉矩控制法最大的問題在於有限的電壓向量做切換時之轉矩變化，造成馬達噪音及震動的產生，多以空間電壓向量調變技術之控制法來克服，是以更多的電壓向量與高階磁滯比較器能使磁通變化平順，但增加電壓向量與磁滯比較器的階層，無法有效消除轉矩漣波的產生，原因於開關元件並無法快速的響應。
因此本論文提出固定磁通變量直接轉矩控制法，藉由即時的空間電壓向量運算，保持固定磁通變量，有效抑制轉矩漣波的產生，並在磁通誤差量大時使用傳統方法，而當磁通誤差量到達目標範圍後改為固定磁通變量法，如此即可實現兼顧暫態與穩態性能之控制法。
本研究以定點式數位訊號處理器與智慧型功率模組為基礎，實現全數位化驅動器，不但有效簡化電路，亦提升了系統之彈性，最後以實驗證實其可行性。

This research investigated the phenomenon of over-large ripple generated by direct torque control operated induction motors, and developed a fixed flux variation direct torque control to sufficiently inhibit the ripple.
Direct torque control is uncomplicated, easy to practice, and not affected much by factor variations. However, a huge problem of direct torque control is that switching limited voltage vector results in a torque change, and this change causes noise and vibration of the motor. This problem is usually solved by spatial voltage vector adjusting control, which uses more voltage vector and advanced hysteresis comparators to stablize the variation of flux. However, increasing voltage vector and the level of hystersis comparator cannot eliminate torque ripple efficiently because the switch element cannot follow this rapid adjustment.
This thesis proposed fixed flux variation direct torque control to stabilize the flux variation and inhibit torque ripple generation by instant spatial voltage vector computation. The traditional method is used when flux deviation is big; the fixed flux variation method is used when the flux deviation decreases to the targeted range. Therefore, this newly developed method accomplishes both transient and steady state control.
This research developed a full-digital drive based on the fixed-point digital signal processor and intelligent power module. This drive not only efficiently simplifies the circuit, it also increases the flexibility of the system. Finally, the experiment confirmed the feasibility of this method.

[1] T. A. Lipo, “Recent progress in the development of solid-state AC motor drives,”IEEE Trans. Power Electron., vol. 3, no. 2, pp. 105-117, Apr. 1988.
[2] F. Blaschke, “The principle of field-orientation as applied to the transected closed-loop control system for rotating-field machines,” Siemens Rev., vol. 34, pp. 217-220, 1972.
[3] G. Buja and D. Casadei,“DTC-based strategies for induction motor drives,”IECON‘97 23rd Int. Conf. Ind. Electron., Control and Instrumentation, vol. 4, pp. 1506-1516, 1997.
[4] E. K. K. Sng, A. C. Liew and T. A. Lipo, “New observer- based DFO scheme for speed sensorless field-oriented drives for Low-Zero-Speed operation,” IEEE Trans. Power Electron., vol. 13, no. 5, pp. 959-968, Sep. 1998.
[5] M. S. N. Said and M. E. H. Benbouzid,“Induction motors direct field oriented control with robust on-line tuning of rotor resistance,”IEEE Trans. Energy Conversion, vol. 14, no. 4, pp. 1038-1042, Dec. 1999.
[6] A. Consoli, G. Scarcella and A. Testa,“A new zero-frequency flux-position detection approach for direct-field-oriented- control drive,”IEEE Trans. Ind. Appl., vol. 36, no. 3, pp. 797-804, May-Jun. 2000.
[7] I. Takahashi and T. Noguchi, ”A new quick-response and high-efficiency control strategy of an induction motor,” IEEE Trans. Ind. Appl., vol. IA-22, no. 5, pp. 820-827, Sep./Oct. 1986.
[8] G. Buja and D. Casadei,“DTC-based strategies for induction motor drives,”IECON‘97 23rd Int. Conf. Ind. Electron., Control and Instrumentation, vol. 4, pp. 1506-1516, 1997.
[9] T. G. Haberler and D. M. Divan,“Control strategies for direct torque control using discrete pulse modulation,”IEEE Trans. Ind. Appl., vol. 27, no. 5, pp. 893-901, Sep.-Oct. 1991.
[10] H. Y. Zhong, H. P. Messinger and M. Rashad,“A new micro- computer based direct torque control system for three phase induction motor,”IEEE Trans. Ind. Appl., vol. 27, no. 2, pp. 294-298, Mar.-Apr. 1991.
[11] T. G. Habetler, F. Profumo, M. Pastorelli and L. M. Tolbert, “Direct torque control of induction machines using space vector modulation,”IEEE Trans. Ind. Appl., vol. 28, no. 5, pp. 1045–1053, Sep./Oct. 1992.
[12] D. Casadei, G. Grandi, G. Serra and A. Tani,“Effects of flux and torque hysteresis band amplitude in direct torque control of induction machines,”IECON‘94 20th Int. Conf. Ind. Electron., Control and Instrumentation, vol. 1, pp. 299-304, 1994.
[13] M. P. Kazmierkowski and A. B. Kasprowicz,“Improved direct torque and flux vector control of PWM inverter-fed induction motor drives,”IEEE Trans. Ind. Electron., vol. 42, no. 4, pp.344-349, Aug. 1995.
[14] C. Attaianese, A. Perfetto, A. Damiano and I. Marongiu,“A direct torque control algorithm imposing the mechanical response of speed controlled induction motor drives,”ISIE’96, Proc. IEEE Int. Symp. Ind. Electron., vol. 1, pp. 157-162, 1996.
[15] J. N. Nash,“Direct torque control, induction motor vector control without an encoder,”IEEE Trans. Ind. Appl., vol. 33, no. 2, pp. 333-341, Mar./Apr. 1997.
[16] A. Purcell and P. Acarnley,“Multilevel hysteresis comparator forms for direct torque control schemes,”Electron. Letters, vol. 34, no. 6, pp. 601–603, Mar. 1998.
[17] C. G. Mei, S. K. Panda, J. X. Xu and K. W. Lim,“Direct torque control of induction motor – variable switching sectors,”IEEE PEDS’99 Int. Conf. Power Electron. and Drive Systems, vol. 1, pp. 80-85, 1999.
[18] T. G. Habetler, F. Profumo, M. Pastorelli and L. M. Tolbert, “Direct torque control of induction machines using space vector modulation,”IEEE Trans. Ind. Appl., vol. 28, no. 5, pp. 1045–1053, Sep./Oct. 1992.
[19] C. Attaianese, V. Nardt, A. Perfetto and G. Tomasso,“Vectorial torque control : A novel approach to torque and flux control of induction motor drives,”IEEE Trans. Ind. Appl., vol. 35, no. 6, pp. 1399-1405, Nov.-Dec. 1999.
[20] D. Casadei, G. Serra and K. Tani,“Implementation of a direct control algorithm for induction motors based on discrete space vector modulation,” IEEE Trans. Power Electron., vol. 15, no. 4, pp. 769-777, Jul. 2000.
[21] J. H. Lee, C. G. Kim and M. J. Youn, “A dead-beat type digital controller for the direct torque control of an induction motor,” IEEE Trans. Power Electron., vol.17, no. 4, pp. 739-746, Sep. 2002.
[22] J. Maes and J. Melkebeek, “Discrete direct torque control of induction motors using back e.m.f. measurements,” in Conf. Rec. IEEE-IAS Annu. Meeting, vol. 1, pp. 407-414, 1998.
[23] D. Casadei, G. Serra and A. Tani, “Implementation of a direct torque control algorithm for induction motors based on discrete space vector modulation” IEEE Trans. Power Electron., vol.15, no. 4, Jul. 2000.
[24] D. Casadei, F. Profumo, G. Serra and A. Tani, “FOC and DTC: Two viable schemes for induction motors torque control,” IEEE Trans. Power Electron., vol. 17, pp. 779-787, Sep. 2002.
[25] D. Casadei, G. Serra and A. Tani, “Constant frequency operation of a DTC induction motor drive for electric vehicle,“ in Proc. ICEM’96, vol. 3, pp. 224-229, 1996.
[26] B. Singh and D. Goyal, “Improved DSVM-DTC based current sensorless permanent magnet synchronous motor drive,” in Proc. PEDS’07, Bangkok, Nov. 27-30, pp. 1354-1360, 2007.
[27] K. Gulez, A. A. Adam and H. Pastaci, “A novel direct torque control algorithm for IPMSM with minimum harmonics and torque ripples,” IEEE/ASME Trans. Mechatron., vol. 12, pp. 223-227, Apr. 2007.
[28] L. Lin, H. Zhong, J. Zhang, Y. Deng and Y. Zou, “A three-level induction motors DTC algorithm based on fixed synthesizing vectors with reduced flux and torque ripples,” in Proc. ICEMS, 2008, Huazhong, China, pp. 1359-1364. Oct. 17-20, 2008.
[29] K. Gulez, A. A. Adam and H. Pastaci, “A novel direct torque control algorithm for IPMSM with minimum harmonics and torque ripples,” IEEE/ASME Trans. Mechatron., vol. 12, no. 2, pp. 223-227, Apr. 2007.
[30] 陳泓傑, “直接轉矩控制於永磁同步馬達之轉矩漣波改善研究,” 中央大學碩士學位論文，民國96年6月。
[31] 鄧述先, “直接轉矩控制感應馬達驅動器之新式反流器切換策略之研究,” 成功大學碩士學位論文，民國94年6月。
[32] A. Tripathi, A. M. Khambadkone and S. K. Panda, “Stator flux based space vector modulation and closed loop control of the stator flux vector in overmodulation into six-step mode, ”IEEE Trans. Power Electron., vol. 19, no. 3, pp. 775-782, May 2004.
[33] A. Tripathi, A. M. Khambadkone and S. K. Panda, “Direct method of over modulation with integrated close loop stator flux vector control, “IEEE Trans. Power Electron., vol. 20, no. 5, pp. 1161-1168, Sep. 2005.
[34] A. Tripathi, A. M. Khambadkone and S. K. Panda, “Torque ripple analysis and dynamic performance of a space vector modulation based control method for AC-drives, ”IEEE Trans. Power Electron., vol. 20, no. 2, pp. 485-492, March 2005.
[35] A. Tripathi, A. M. Khambadkone and S. K. Panda, “Dynamic control of torque in over modulation and in the field weakening region,”IEEE Trans. Power Electron., vol. 21, no. 4, pp. 1091-1098, Jul. 2006.
[36] M. Cirrincione, M. Pucci, G. Vitale and G. Cirrincione, “A new direct torque control strategy for the Minimization of common-mode emissions, ”IEEE Trans. Ind. Appl., vol. 42, no. 2, pp. 504-517, Mar.-Apr. 2006.
[37] J. K. Kang and S. K. Sul, “New direct torque control of induction motor for minimum torque ripple and constant switching frequency, ”IEEE Trans. Ind. Appl., vol. 35, no. 5, pp. 1076-1082, Sep./Oct., 1999.
[38] Y. S. Lai and J. H. Chen, “A new approach to direct torque control of induction motor drives for constant inverter switching frequency and torque ripple reduction,” IEEE Trans. Energy Con., vol. 16, no. 3, pp. 220-227, Sep. 2001.
[39] J. K. Kang and S. K. Sul, “Analysis and prediction of inverter switching frequency in direct torque control of induction machine based on hysteresis bands and machine parameters, “IEEE Trans. Ind. Electron. , vol. 48, no. 3, pp. 545-553, Jun. 2001.
[40] K. B. Lee, J. H. Song, I. Choy and J. Y. Yoo ,” Torque ripple reduction in DTC of induction motor driven by three-level inverter with low switching frequency,” IEEE Trans. Power Electron., vol. 17, no. 2, pp. 255-264, Mar. 2002.
[41] direct torque control of induction machines,” IEEE Trans. Ind. Appl., vol. 42, no. 6, pp. 1358-1366, Nov./Dec. 2006.
[42] P. Vas, “Vector control of AC machines,” Clarendon Press Oxford, 1990.
[43] D. W. Novotny and T. A. Lipo, “Vector control and dynamic of AC drives,” Clarendon Press Oxford, 1990.
[44] B. K. Bose, “Power electronics and AC drives,” Englewood Cliffs, Prentice-Hall, 1986.
[45] R. Krishnan, “Electric motor drives modeling, analysis and control,” Prentce-Hall, Inc., 2001.
[46] Microchip Technology Inc., “An introduction to AC induction motor control using the dsPIC30F / dsPIC33F DSC,” 2005.
[47] Microchip Technology Inc., “dsPIC family data sheet,” 2007.
[48] Microchip Technology Inc., “Using the dsPIC30F / dsPIC33F for vector control of an ACIM,” 2007.
[49] 曾百由編著，數位訊號控制器原理與應用，宏友圖書開發股份有限公司，民國94年12月。
[50] 劉昌煥編著，交流電機控制，東華書局，民國94年9月第三版。
[51] Cyntec, “IPM SDIP-IPM IM22400E Data Sheet,” 2007.
[52] 張西川編譯，電子電路零組件應用手冊，全華科技圖書股份有限公司，民國89年9月。