臺灣博碩士論文加值系統

對於具有九槽十二極的三相直流無刷的主軸馬達而言, 作為轉
子的永久磁石是馬達中最重要的元件之一。因此，在實際應用上，
對充磁座作精確的設計，來調整磁石的磁特性是值得注意且可行
的。在今日，藉由使用電腦與CAD套裝軟體，可以方便地分析充磁
座的設計對磁石的磁場分布與對馬達性能的影響。

在本文中，將表現充磁座的幾何形狀與瞬間充磁電流會如何影
響磁場分布、頓轉扭矩、感應電動勢常數等。從最小的頓轉轉矩表
現來看，可以考慮以充磁座Type R4於激磁電流7KA下來充磁的磁
石，且置入馬達後表現出的單相反電動勢常數Ke略小於以Type Rf
於激磁電流7KA下來充磁的磁石所表現出最高的Ke(約小6.5%)。

至於理想徑向飽和磁石雖在磁石內緣有最高的磁通密度Bm，
但因受到與矽剛片定子的磁耦合影響，並沒有提供最高的轉矩，卻
有最高的頓轉轉矩，不利於馬達的運轉性能。

總而言之，以磁路模擬建立充磁條件之資料庫來改善置入以較
低的外加磁場作磁化的磁石的馬達性能，是可行的。

For the three-phase brushless DC spindle motor with 9-slot stator and
12-pole rotor, the permanent magnet used as the rotor is one of the most
important components. Therefore, it''s noticeable and available to perform
accurate design of the impulse multipole magnetizing fixture to adjust
the properties of the magnet in the application. Today, it''s convenient to
analyze the influence of the fixture design on the field distribution of the
magnet and on the performance of the motor with the usage of computers
and CAD software packages .

In this study, it''s showed that how geometric shape of fixtures and
impulse multipole magnetizing currents can effect the field distribution,
cogging torque, back emf''s constant, and etc.. In the view of performing
the lowest cogging torque, it''s considerable on condition that the magnet
is magnetized in the fixture is chosen Type R4 with exciting current of
7KA, and arranged in the motor with performing one-phase back-emf
(Ke) which is slightly smaller than the highest one of the magnet under
magnetization in the fixture Type Rf with the exciting current of
7KA(about 6.5% off).

There is the highest magnitude (Bm) of flux density in the inner side of
ideal radial saturated magnetized magnet, which is not the best choice
because of its performance of the highest cogginig torque but not the
highest Ke in the motor.

Consequently, the database of magnetization condition of the magnet
developed by the simulation of magnetic circuit is avaliable to improve
the peformance of the spindle motor by the magnetization in low-level
applied field.

書名頁...................................................... i
論文口試委員審定書.......................................... ii
授權書...................................................... iii
摘要........................................................ v
致謝........................................................ vii
目錄........................................................viii
圖錄........................................................ x
表錄........................................................xiii

一、簡介.................................................... 1
二、研究目標與範圍.......................................... 3
2.1 研究目標與研究範圍............................. 3
2.2 電磁理論簡介................................... 4
三、磁路模擬與原理.......................................... 10
3.1 有限元素法應用之原理........................... 11
3.2 馬達中力與力矩之計算方法....................... 14
3.3 反電動勢計算方法............................... 15
3.4 磁路模擬流程................................... 17
四、研究內容................................................ 20
4.1 材料特性與量測................................. 20
4.2 充磁機參數與外加磁場........................... 28
4.3 馬達特性量測................................... 31
4.4 磁路模擬之模型................................. 35
五、研究結果與分析.......................................... 37
5.1 充磁座磁路模擬之結果........................... 43
5.3 馬達磁路模擬之結果............................. 50
六、討論與結論.............................................. 55
參考文獻.................................................... 56
附錄 釹鐵硼磁石充磁作之設計與分析.......................... 57
自傳........................................................ 63

[1] D. Howe and Z. Q. Zhu, "The Influence of Finite Discretisation on
the Prediction of Cogging Torque in Permanent Magnet Excited
Motors", IEEE Trans. on Magnetics, Vol. 28, No.2, pp1080~1083,
1992

[2] D. A. Lowther, P. P. Silvester, Computer-Aided Design in
Magnetics, Springer-verlag New York Inc., pp68~74, 1986

[3] Z. Q. Zhu and D. Howe, "Analytical Prediction of the Cogging
Torque in Radial-Field Permanent Magnetic Brushless Motors",
IEEE Trans. on Magnetics, Vol. 28, No.2, pp1317~1374, 1992

[4] B. D. Cullity, Introduction to Magnet Materials, pp49~61, 1972

[5] G. W. Jewell, D. Howe ,and C. D. Riley, "The Design of Radial-Field
Multiple Impulse Magnetizing Fixtures for Isotropic NdFeB Magnets",
IEEE Trans. on Magnetics, Vol. 33, No.1, pp708~722, 1997

[6] D. Chiang, S. J. Wang ,and D. R. Huang, "Magnetic Profiles of
Bonded Magnets Affected by the Magnetizing Fixtures", J. Appl.
Phys. 79(8), American Institute of Physics, pp5560~5562, 1996

[7] 加藤幸雄著，蘇品書譯，電子電氣有限要素基本理論篇，復漢出版社，
76年1月

[8] 加藤幸雄著，蘇品書譯，電子電氣有限要素應用實務篇，復漢出版社，
76年1月