陽毅平Yang, Yee-Pien臺灣大學:機械工程學研究所巫承儒Wu, Cheng-JuCheng-JuWu2010-06-302018-06-282010-06-302018-06-282009U0001-2707200911260700http://ntur.lib.ntu.edu.tw//handle/246246/187097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。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 hybridagnetomotive 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 showhat 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.中文摘要 ......................................................................................................... Ibstract ....................................................................................................... IIIontents ......................................................................................................... Vist of Figures .......................................................................................... VIIIist of Tables .............................................................................................. XIIist of Symbols ........................................................................................ XIIIhapter 1 Introduction ................................................................................. 1.1 Background.................................................................................................................... 1.2 Literature Review .......................................................................................................... 5.2.1 Topology of Permanent Magnetic Machine ......................................................... 5.2.2 Studies on the Demagnetization Phenomenon ................................................... 17.3 The Motivation and Objective of the Research ........................................................... 22.4 Thesis Organization ..................................................................................................... 23hapter 2 A Flux Shunt DC Motor with an Anti-Demagnetizationechanism ................................................................................. 26.1 Design Concept of the Flux Shunt DC Motor ............................................................. 26.2 Specifications of a Flux Shunt DC Motor Prototype ................................................... 34.3 Design Procedure ......................................................................................................... 35.4 Demagnetization of the Permanent Magnet ................................................................ 37.5 The Causes of Irreversible Demagnetization ............................................................... 39.6 The Effects of Irreversible Demagnetization ............................................................... 45hapter 3 Material Selection Analysis...................................................... 47.1 Brief Review of Magnetic Materials ........................................................................... 47.2 Selection of Armature Lamination Steels .................................................................... 50.3 Selection of Stator Permeable Pole Face Material ...................................................... 52.4 Selection of Permanent Magnet Materials ................................................................... 53hapter 4 The Magnetic Circuit Model and Optimal Design................. 57.1 The Magnetic Circuit [30] ........................................................................................... 57.1.1 The Basic Concept of a Magnetic Circuit .......................................................... 57.1.2 The PM Magnetic Circuit Model ....................................................................... 61.1.3 Flux Linkage and Back-EMF ............................................................................. 64.2 Determination of Design Variables .............................................................................. 66.3 Magnetic Equivalent Circuit Construction .................................................................. 69.3.1 Calculation of Air Gap Permeance ..................................................................... 72.3.2 Calculation of Magnet, Permeable Material, and Leakage Permeance .............. 76.3.3 Calculation of Air Gap Flux ............................................................................... 78.3.4 Calculation of Torque ......................................................................................... 81.3.5 Calculation of Inductance ................................................................................... 83.3.6 Calculation of Speed .......................................................................................... 87.4 Sensitivity Analysis ..................................................................................................... 90.4.1 Objective Functions............................................................................................ 90.4.2 Sensitivity Analysis ............................................................................................ 96.4.3 Sensitivity Indices ............................................................................................ 110.5 Optimal Design...........................................................................................................113.5.1 The Optimal Design Tool ................................................................................. 113.5.2 Optimal Design Process ................................................................................... 115hapter 5 Finite Element Verification.....................................................120.1 Introduction of Finite Element Analysis Tools .......................................................... 120.2 The Flux Density Distribution in the Air Gap ........................................................... 122.3 Thermal Analysis ....................................................................................................... 126hapter 6 Experiment and Discussion.................................................... 128.1 Fabrication................................................................................................................. 128.2 Experimental Equipment ........................................................................................... 131.3 Performance Test of the Flux Shunt DC motor ......................................................... 134.4 Temperature Test ........................................................................................................ 155.5 Measurement of Back EMF Waveform ..................................................................... 158hapter 7 Conclusions.............................................................................. 161.1 Conclusions................................................................................................................ 161.2 Contributions..............................................................................................................163.3 Future Work............................................................................................................... 164eferences .................................................................................................. 165ppendix A ................................................................................................. 169ppendix B ................................................................................................. 177ppendix C ................................................................................................ 187ppendix D ................................................................................................ 1904196930 bytesapplication/pdfen-US退磁磁路永久磁鐵直流電機磁通分流混合激磁Demagnetizationmagnetic circuitspermanent magnetDC machineflux shunthybrid excitationthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/187097/1/ntu-98-R96522803-1.pdf