本研究主要目的是評估三角形連接中性點接地結構的配電變壓器在配電系統的損失。首先，運用變壓器數學模型與重疊定理，將三角形連接中性點接地結構的配電變壓器轉換為三相多繞組變壓器電路模型。其次，將此變壓器電路模型導入 IEEE 4 Nodes Test Feeder 標準系統，藉以比較供電品質與變壓器效率的差異。最後，以台灣現有的配電系統為例，將缺相的配電變壓器更換為此變壓器，結果顯示可改變饋線損失與電壓降。本研究開發的程式，皆在 Matlab/Simulink 實現，已使用 IEEE 標準系統驗證其正確性。

The main purpose of this study is to evaluate the power loss of a distribution transformer with the Delta-connected neutral grounding structure in the distribution system. First, the Delta-connected neutral grounding structure was converted into three-phase multi-winding transformer circuit model with the transformer mathematical model and the superposition theorem. Secondly, the transformer circuit model is imputed into the IEEE 4 Nodes Test Feeder standard system to compare the difference of power supply quality and transformer efficiency. Finally, the existing power distribution
system in Taiwan is used as a benchmark. Distribution transformers with UV connection replaced by the proposed transformers. The results show that are the feeder are power loss and voltage drop can be improved effectively. The programs developed in this research are all implemented in Matlab/Simulink, and their correctness has been verified using the IEEE Standard System.

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