具抗逆激磁機構之磁通分流式直流馬達設計與製作

Design and Fabrication of a Flux Shunt DC Motor with an Anti-Demagnetization Mechanism

巫承儒(Cheng-Ju Wu)

指導教授 ： 陽毅平

國立臺灣大學/工學院/機械工程學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.02867

摘要

高性能永磁式電機使用具有強大磁能積的稀土元素銣鐵硼永久磁鐵，可以提供強大的磁場，用來取代電流激磁，達成省電效益。然而，永久磁鐵所提供的磁場無法調控，而且成本高昂，若折衷採用次階永久磁鐵，則於受到逆激磁可能產生不可逆的退磁，導致馬達輸出效能變差。為解決上述問題，本研究採用次階永久磁鐵與線圈激磁之混合磁動勢，做為可控磁場，並且結合磁通分流之概念，設計出創新的電機結構，稱為具抗逆激磁機構之磁通分流式直流馬達，能克服傳統永磁電機性能上的先天限制。研究中提出一套完整的馬達設計流程，首先由磁路觀點與馬達設計方程式建立本馬達的二維磁路模型，結合多目標函數最佳化設計軟體，同時對馬達輸出力矩、轉速、效率以及重量進行最佳化設計，並且經由有限元素分析軟體加以驗證，最後製作出馬達原型，並實測出馬達性能。根據馬達測試結果顯示，增加線圈激磁電流能使馬達在定電樞電壓下的效率與力矩提高，且控制線圈激磁電流能改變馬達定電樞電壓下的轉速，此優異電機特性可應用於無段變速伺服驅動系統。

關鍵字

退磁 ； 磁路 ； 永久磁鐵 ； 直流電機 ； 磁通分流 ； 混合激磁

並列摘要

High energy product rare earth magnets are widely used in high performance permanent magnet machines to replace the current excitation methods and to improve machine efficiency. However, the magnetic field provided by a permanent magnet cannot be adjusted and the price of rare earth magnets is high. If the machine adopts low grade permanent magnet, there is a high risk of irreversible demagnetization. To address this problem, a novel DC commutator machine that incorporates the concepts of hybrid
magnetomotive force and flux shunt is proposed in this research. The hybrid magnetomotive force is provided by a low grade permanent magnet and an additional field winding to form an adjustable magnetic field, which is connected in the flux shunt magnetic circuit. The design procedures of this machine are presented in the following order: magnetic circuit model construction, optimization, and finite element analysis verification. Finally, a conceptual prototype is fabricated. The experimental results show
that increases in the field winding current can increase the machine efficiency and torque, while the armature voltage is kept constant. Moreover, the machine speed can also be changed by controlling the field winding current at constant armature voltage. This excellent machine characteristic could be applied to a continuous speed variation servo drive system.

並列關鍵字

Demagnetization ； magnetic circuits ； permanent magnet ； DC machine ； flux shunt ； hybrid excitation

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