爪極式永磁型步進馬達之性能分析研究

Analytical study on the performance of the claw-poles PM stepping motor

陳威成(Wei-Cheng Chen)

指導教授 ： 劉宗平

元智大學/工程學院/電機工程學系/碩士(2002年)

摘要

本文的研究重點在於探討掃描器用馬達的組立方式，將上下定子以不同的間隙或材質隔開，試圖改變馬達的磁性轉子與定子間的磁交互作用，目的是找出哪種狀況下會有小的頓轉力矩。頓轉力矩在馬達運轉時會與激磁時之力矩合成保持力矩，產生力矩相消長的情形，如果此合成力矩變動過大，力矩弦波波形嚴重失真，將直接影響步進角精確度，所以我們要設法降低頓轉力矩。同樣的，降低了頓轉力矩可使馬達在高速工作時表現出較佳的特性，不但降低了振動、噪音，同時也提升了步進角精確度，對於整個馬達運用系統來說，就是增加了產品的解析度，提升了產品的競爭力。
雖然有關步進馬達特性的研究很多，但大多偏重於電氣特性技巧的探討，尤其是驅動電路及控制方面的研究，而利用磁路模擬技巧來探討馬達性能的分析卻比較少。所以我們將以有限元素法為基礎，希望藉由磁路模擬和一連串的實驗印證，證實我們所建構的馬達模型是正確的，或是可接受的，以建立步進馬達微型化之基礎。此外，如果求證無誤或是確實可用，那麼在往後開發此型馬達的工作上，即可因透過磁路模擬的分析技術，而節省了大量的研發成本。

關鍵字

爪極式永磁型步進馬達 ； 無激磁頓轉力矩(D.T.) ； 保持力矩(H.T.) ； 磁路模擬 ； 有限元素法 ； 步進角誤差

並列摘要

The key point of our study is to improve the performance by changing the assemblage of the claw-poles stepping motor used in the scanner. The upper and lower stators are separated in different intervals with different materials.
Generally, there is an interaction between the detent torque and the holding torque. In order to get lower detent torque, we tried to eliminate the inherent magneto-coupling interaction occurred between the stator and the magnetic rotor. If the sharp variations from the detent torque appeared, the typical pattern of the sinusoidal wave of the holding torque might seriously be distorted. Thus, the disturbance can directly affect the accuracy of the step angle. That’s the reason why we need the lower detent torque. It is known that the better performance can be obtain by decreasing the detent torque as the motor operated at high speed. Therefore, lower detent torque can decrease the vibration and the noise to increase the accuracy of the step angle. If this work can be accomplished, the resolution of the scanning will be improved substantial.
Most researches on stepping motors focus on their electrical properties, especially in designing the control circuit of the driver. However, few papers reported the performance of the motors with the magnetic—circuit simulation technique. We examined the simulation results with a serious of experimental data. That will help us to confirm whether the models used in the simulations are correct and acceptable or not. If they work, we can build up the fundamental models for miniaturizing the stepping motor. Consequently, we can reduce the cost whenever we develop a new motor.

並列關鍵字

claw-poles PM stepping motor ； detent torque ； holding torque ； magnetic-circuit simulation ； finit element method ； step position error

參考文獻

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