就目前市面上之電動代步車而言，其動力源大部分仍使用直流有刷馬達。此類馬達因具有電刷、整流子以及定子永久磁鐵之機械結構，故其天生存在著大起動轉矩及控制簡單之優點。然而，這樣的機械式換相往往帶來了低功率密度、低可靠度以及散熱不易之問題。反觀永磁無刷馬達於結構上散熱良好，且效率高、不需定時維修，在電動代步車應用上具有高度潛力。因此，本論文將探討具梯形波與弦波反電動勢之永磁無刷馬達於方波、弦波電流驅動下之性能表現，並以低解析度之霍爾感測元件實現弦波電流驅動，達到低成本驅動器之目的。最後，針對各驅動策略之效率及最高轉速限制進行傅立葉分析及實驗驗證，結果發現使用方波、弦波之混合操作模式，可發揮永磁無刷馬達於不同轉速下之最大效能。因此本論文規劃了一套能即時切換方波與弦波電流之驅動方式，以提升電動代步車高速與低速下之穩態性能。

Nowadays, most mobility scooters are equipped with the DC brush motor. This type of motor has mechanical structures such as stator permanent magnets, brush, and a commutator. Therefore, it has large start-up torque and is easy to control. However, this kind of mechanical commutation often leads to drawbacks such as low power density, low reliability, and difficulties to disburse heat. In contrast with the DC brush motor, the permanent magnet brushless motor (PMBLM) has high efficiency and does not need regular maintenance. Hence, PMBLM has great potential in becoming the power source for mobility scooters. In this thesis, the performance of the PMBLM with ideal trapezoidal and sinusoidal back-emf waveforms under rectangular and sinusoidal current drives is evaluated. To reduce the cost, low-resolution Hall sensors are used to implement the sinusoidal current drives. Both the Fourier analysis and experimental results indicate that the proposed hybrid rectangular and sinusoidal current operations can indeed improve the performance of the permanent magnet brushless motors under various driving strategies.

[1] P. Pillay, and R. Krishnan, “Application characteristics of permanent magnet synchronous and brushless dc motors for servo drives,” IEEE Transactions on Industry Applications, vol. 27, pp. 986-996, 1991.
[2] Z. Q. Zhu, J. X. Shen, and D. Howe, “Flux-weakening characteristics of trapezoidal back-emf machines in brushless dc and ac modes,” in Proceedings of the IEEE Power Electronics and Motion Control Conference, Shanghai, China, 2006, pp. 1-5.
[3] Y. F. Shi, Z. Q. Zhu, and D. Howe, “Torque-speed characteristics of interior-magnet machines in brushless ac and dc modes, with particular reference to their flux-weakening performance,” in Proceedings of the IEEE Power Electronics and Motion Control Conference, Shanghai, China, 2006, pp. 1-5.
[4] 魏道炎，『直流無刷馬達驅動技術之研究，』 碩士論文，國立台灣大學機械工程學系，2002。
[5] T. M. Jahns, G. B. Kliman, and T. W. Neumann, “Interior Permanent-Magnet Synchronous Motors for Adjustable-Speed Drives,” IEEE Transactions on Industry Applications, vol. IA-22, pp. 738-747, 1986.
[6] T. M. Jahns, “Flux-weakening regime operation of an interior permanent-magnet synchronous motor drive,” IEEE Transactions on Industry Applications, vol. IA-23, pp. 681-689, 1987.
[7] S. Morimoto, M. Sanada, and Y. Takeda, “Design and control system of inverter-driven permanent magnet synchronous motors for high torque operation,” IEEE Transactions on Industry Applications, vol. 39, no. 3, pp. 792-801, 2003.
[8] S. Morimoto, M. Sanada, and Y. Takeda, “Wide-speed operation of interior permanent magnet synchronous motors with high-performance current regulator,” IEEE Transactions on Industry Applications, vol. 39, no. 3, pp. 792-801, 1994.
[9] T. M. Jahns, “Torque production in permanent-magnet synchronous motor drives with rectangular current excitation,” IEEE Transactions on Industry Applications, vol. IA-20, pp. 803-813, 1984.
[10] R. C. Becerra, and M. Ehsani, “High-speed torque control of brushless permanent magnet motors,” IEEE Transactions on Industrial Electronics, vol. 35, pp. 402-406, 1988.
[11] S. K. Safi, P. P. Acarnley, and A. G. Jack, “Analysis and simulation of the high-speed torque performance of brushless dc motor drives” IEE Proceedings, Electric Power Application, vol. 142, no. 3, pp. 191-200, 1995.
[12] C. C. Chan, J. Z. Jiang, W. Xia, and K.T. Chau, “Novel wide range speed control of permanent magnet brushless motor drives,” IEEE Transactions on Power Electronics, vol. 10, pp. 539-546, 1995.
[13] J. S. Lawler, J. M. Bailey, J. W. McKeever, and J. Pinto, “Limitations of the conventional phase advance method for constant power operation of the brushless dc motor,” in Proceedings of the IEEE SoutheastCon’02, vol. SEC-118, Columbia, South Carolina, USA, 2002, pp. 174-180.
[14] B. M. Nquyen, and M. C. Ta, “Phase advance approach to expand the speed range of brushless dc motor,” in Proceedings of the IEEE Power Electronics and Drives Systems Conference, Bangkok, Thailand, 2007, pp. 1255-1262.
[15] N. A. Patil, and J. S. Lawler, “Experimental verification of conventional phase advancement method for surface permanent magnet motor with fractional-slot concentrated windings,” in Proceedings of the IEEE Southeastcon, Huntsville, Alabama, USA, 2008, pp. 474-479.
[16] A. M. EL-Refaie, T. M. Jahns, P. J. McCleer, and J. W. McKeever, “Experimental verification of optimal flux weakening in surface PM machines using concentrated windings,” IEEE Transactions on Industry Applications, vol. 42, no. 2, pp. 443-453, 2006.
[17] J. S. Lawler, J. M. Bailey, J. W. McKeever, and J. Pinto, “Extending the constant power speed range of the brushless dc motor through dual-mode inverter control,” IEEE Transactions on Power Electronics, vol. 19, no. 3, pp. 783-793, 2004.
[18] P. Pillay, and R. Krishnan, “Modeling, simulation, and analysis of permanent-magnet motor drives, part I: the permanent-magnet synchronous motor drive,” IEEE Transactions on Industrial Electronics, vol. 25, pp. 279-279, 1989.
[19] S. Morimoto, M. Sanada, and Y. Takeda, “High performance current sensorless drive for PMSM and SynRM with only low resolution position sensor,” IEEE Transactions on Industry Applications, vol. 39, no. 3, pp. 792-801, 2003.
[20] F. G. Capponi, G. D. Donato, and L. D. Ferraro, “Brushless AC drive using an axial flux synchronous PM motor with low resolution position sensors,” in Proceedings of the IEEE Power Electronics Specialists Conference, vol. 3, 2004, pp. 2287-2292.
[21] F. C. Lee, “Energy efficient power conversion architecture and management for IT industries,”Virginia Polytechnic Institute and State University, USA, 2008.
[22] 羅銘翔，『永磁同步馬達調速驅動系統於跑步機之研製，』 碩士論文，國立成功大學電機工程學系，2007。
[23] 劉子瑜，『基於弦波電流驅動於永磁同步馬達電流迴路控制之研究，』 碩士論文，國立成功大學電機工程學系，2009。
[24] S. J. Chapman, Electric machinery fundamentals, McGraw-Hill companies, Inc., 2005.
[25] 孫清華，『最新無刷直流馬達』，全華圖書股份有限公司，2001。
[26] R. Carlson, M. Lajoie-Mazenc, and J. C. d. S. Fagundes, “Analysis of torque ripple due to phase commutation in brushless dc machines,” IEEE Transaction on Industry Applications, vol. 28, pp. 632-638, 1992.
[27] D. Hanselman, Brushless permanent magnet motor design, The Writers’ Collective, USA, 2003.
[28] S. Ruangsinchaiwanich, Z. Q. Zhu, and D. Howe, “Influence of magnet shape on cogging torque and back-emf waveform in permanent magnet machines,” in Proceedings of the IEEE Electrical Machines and Systems Conference, Vol. 1, 2005, pp. 284-289.
[29] C. L. Chu, M. C. Tsai, and H. Y. Chen. “Torque control of brushless dc motors applied to electric vehicles,” in Proceedings of the IEEE Electric Machines and Drives Conference, Cambridge, Massachusetts, USA, 2001, pp. 82-87.
[30] 陳瑞霖，『永磁同步電動機轉軸角度估測及驅動系統的研製，』 碩士論文，國立台灣科技大學電機工程系，2006。
[31] A. M. EL-Refaie, D. W. Novotny, and T. M. Jahns, “A simple model for flux weakening in surface PM synchronous machines using back-to-back thyristors,” IEEE Power Electronics Letters, vol. 2, pp. 54-57, 2004.
[32] R. H. Brown, S. C. Schneider, and M. G. Mulligan, “Analysis of algorithms for velocity estimation from discrete position versus time data,” IEEE Transactions on Industrial Electronics, vol. 39, pp. 11-19, 1992.
[33] H. Zeroug, D. Holliday, D. Grant, and N. Dahnoun, “Perfomance prediction and field weakening simulation of a brushless DC motor,” IEE Proceedings, Power Electronics and Variable Speed Drives, no. 475, pp. 321-326, 2000.