有限元素於不同電磁結構之研究：以變壓器為例

本研究提出單相變壓器於不同搭接結構鐵芯電磁分析，並針對鐵芯損失及噪音振動關係進行研究。當鐵芯受到激磁時所產生的磁力線，將會通向鐵芯的搭接磁阻，並造成鐵芯磁通密度的變化。基本上，軟磁性材料矽鋼片鐵芯具有磁滯伸縮變化特性，將影響其內部磁通密度分佈情形。本研究提出鐵芯不同搭接結構以及其複合式鐵芯結構等，分析其鐵芯損失、磁通密度、磁力線方向、磁滯伸縮力及噪音振動等相關聯特性。首先，建立本研究變壓器鐵芯之幾何模型，將模型帶入Ansoft Maxwell 3D有限元素法進行電磁分析，實驗樣本包含三角型、橢圓型、正方型、平切型以及斜切型等鐵芯搭接組數，透過有限元素法電磁分析結果，觀察各搭接組其磁特性（磁通密度、磁力線、振動及噪音）結果變化。實驗結果證實，三角型搭接組，因鐵芯磁路路徑短，鐵芯磁阻較小，磁通密度較低，故具有較佳磁特性，平切型搭接組，因氣隙磁阻較大，磁通密度較高，故磁特性較差，另外，本研究提出複合式鐵芯亦能有效降低鐵芯振動。

關鍵字

氣隙；鐵芯損失；振動；有限元素法

並列摘要

This dissertation proposes experimental results for single-phase pad-mounted transformer in electromagnetic study with different multi-step lap joint core structure which is analyzed the magnetism priorities including core loss and vibration. When the transformer core was excited during power rating, the magnetic flux line has passed through the magnetic reluctance of the core, which effect of magnetic flux density on core insides, has been occurred. Basically, soft magnetic silicon steel material characteristic dependent on magnetostriction variation, which is affected to the internal core of magnetic flux density distribution. This dissertation is proposed correlation of multi-step lap’s core joint structures on single-phase distribution transformer, including magnetic flux density, magnetostrictive force, core loss and vibration, respectively. Core laminating length, air-gapped distance of core as well as air-gapped distribution, will be indispensable key point of magnetism characteristic. Firstly, this study presents a geometry model for multi-step lap core. Then, it also established Ansoft Maxwell 3D by using finite element method to analyze the electromagnetic model for each different core structures. Secondly, experimental approach for different core structure, including triangular-step, rectangular-step, oval-step, butt-lap -step and half mitre-lap-step, is used the finite element analysis to simulate electromagnetic properties which is observed different core joint structure dependent on each magnetic variation. It is indicated that a better core property with different joint structure has significantly validated. Consequently, for composited-core structure, is also has shown the results in lower magnetic vibration.

並列關鍵字

Air gap ； Core losses ； Vibration ； Finite element method

參考文獻

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[4]. F. Loffler, H. Pfutzner, T. Booth, and C. Bengtsson, “Influence of air gaps in stacked transformer cores consisting of several packages,” IEEE Transactions on Magnetics, vol. 30, no. 2, pp. 535-544, March 1994.

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[6]. M. V. F. da Luz, P. Dular, J. Vianei Leite, and P. Kuo-Peng, “Modeling of transformer core joints via a subproblem FEM and a homogenization technique,” IEEE Transactions on Magnetics, vol. 50, no. 2, pp. 175-180, February 2014.

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有限元素於不同電磁結構之研究：以變壓器為例

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