脈寬調變造型磁鐵於永磁同步馬達少稀土設計的研究

Study of Less Rare-Earth Permanent Magnet Synchronous Motor with Pulse-Width-Modulation Shaped Magnets

賴冠宇(Guan-Yu Lai)

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(2014年)

https://doi.org/10.6342/NTU.2014.10463

摘要

本文利用脈寬調變技術設計磁鐵外型，其設計目標主要在於減低稀土磁鐵用量，並盡量降低性能損失。在馬達的分析中，利用一維的無槽型馬達氣隙磁通解析解搭配等效磁路模型及槽效應與氣隙漏磁等現象，求得馬達的氣隙磁通密度分布函數，並進一步得到馬達的性能，再利用妥協規劃法來評鑑各磁鐵尺寸的表現，並利用二維有限元素分析模型驗證其準確性。最後選出三組經過設計後的磁鐵和一組未做外型設計的比較其性能及磁鐵使用量上的差異。根據本文的設計方法可以降低9~13%的磁鐵用量，而馬達力矩輸出下降約3~5%，在維持了應有的性能下減少磁鐵用量。

關鍵字

永磁同步馬達 ； 磁鐵表面外形 ； 最佳化設計 ； 少稀土磁鐵 ； 有限元素分析

並列摘要

This thesis proposes a pulse-width modulation (PWM) technology of designing the surface shape of rotor magnet in a permanent magnet synchronous motor (PMSM). The main purpose of the design was to decrease as much amount of rare earth magnets and power losses as possible. An optimal design process uses an analytical magnetic-circuit model for the motor. This model is derived in a form of one-dimensional analytical solution of the slotless air-gap flux density distribution and an equivalent magnetic circuit model. An effective air-gap permeance distribution function is used to correct the flux distribution considering slot effect and flux leakage. In the search of optimum magnet shapes, the Compromise Programming is used to assess a set of magnet parameters by minimizing or maximizing objectives. The two-dimensional finite elements method (FEM) is used to verify and refine the resulting. Finally, three motors of PWM-shaped magnets were chosen for comparing their performance with the motor without PWM-shaped magnets. With the proposed PWM-shaped magnet, the motor were 9.39-13.13% less magnet in volume than the motor without PWM-shaped magnet. However, the corresponding torque is reduced by 3.34-5.87%.

並列關鍵字

permanent magnet synchronous motor ； magnet shape ； optimal design ； less rare-earth magnet ； finite element analysis

參考文獻

[1] W. T. Benecki, T. K. Claggett, S. R. Trout, "Permanent magnets 2010-2020 : a comprehensive overview of the global permanent magnet industry ", 2010

[2] Alliance LLC Official Website. (2013,May). Commodity Price [Online] Available: http://www.allianceorg.com/magnetandmaterialcosts.html

[3] Q. Gu and H. Gao, "Air gap field for PM electric machines," Electric Machines & Power Systems, vol. 10, no. 5, 1985, pp. 459-470.

[4] Z. Zhu and D. Howe, "Instantaneous magnetic field distribution in brushless permanent magnet DC motors. III. effect of stator slotting," IEEE Transactions on Magnetics, vol. 29, no. 1, Jan. 1993, pp. 143-151.

[5] D. G. Gweon, "Effect of stator slotting in the magnetic field distribution of linear brushless permanent magnet motor," Journal of Magnetics, vol. 6, no. 3, Apr. 2001, pp. 101-107.