本論文之目標在於研究傳統配電用三相低壓乾式變壓器，在不同疊片鐵心型式下對變壓器鐵心內部磁場分佈的影響。本論文提出10種新型鐵心型式，以與傳統E、I型式鐵心變壓器特性做比較。
　　本論文首先根據實際量測以及有限元素之電磁模擬結果比對，求出既有E、I型式鐵心變壓器的等效電路參數，並且建立此變壓器之軟體模型，再以為此基礎擴展出其他10種相同容量的新型鐵心變壓器，以分析各個不同鐵心型式變壓器的運作情形與優缺點，最後再模擬該變壓器的鐵共振與突入電流的暫態響應。本論文之研究成果可給予未來三相低壓乾式變壓器產品的鐵心型式及製造提供新的開發方向，以提高相同類型變壓器產品的競爭力。

　　The purpose of this thesis is to analyze the influence of lamination shape and its core improvement on magnetic field distribution inside iron core of three-phase low-voltage dry-type distribution transformers. This thesis proposes 10 different laminated-core types to compare the performance of the new core types with the one of E-I laminated-core type. The electromagnetic field simulated software based on finite-element method (FEM) is employed to simulate the magnetic field distribution in the iron core of the studied three-phase transformer with various new core types.
　　The measured results of the studied transformer are first compared with the simulated results to obtain the parameters of equivalent circuit of E-I laminated-core type transformer and then establish its simulated FEM model. The characteristics of ten different laminated-core types based on this model are then compared with the ones of the E-I laminated-core type transformer. Finally, simulated transient responses of both ferroresonance and inrush current of the studied transformer are presented. The proposed new core type for the three-phase distribution transformers can give a new manufactured direction to enhance the competitive ability in the world.

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