本論文主旨為研製一台固態變壓器，架構採用高頻操作的主動雙橋式轉換器。傳統變壓器在電力系統中被廣泛使用，以執行許多功能，如電氣隔離、電壓轉換、雜訊隔離等等。但因傳統變壓器有體積較大、重量較重等問題，故需要新的技術來取代。而採用高頻操作的固態變壓器便是其中之一，透過提升操作頻率的方式，減小變壓器的尺寸與重量；另一方面，透過相移調變控制功率潮流的大小與方向。但因採用高頻操作的關係，在輸入輸出側均需使用二階低通濾波器來濾除高頻成分。因此，在設計時需要仔細考量，以免喪失減少整體變壓器體積重量的目的。
本論文實際完成一台輸入電壓為220 Vrms、輸出電壓為220 Vrms以及輸出功率2 kW，以交流-交流主動雙橋式轉換器為應用的固態變壓器原型，並以數位訊號處理器來實現數位控制，在不同的負載下效率均在92%以上。

In this thesis, a solid-state transformer is studied and implemented. The structure adopted is a high-frequency operated active-dual-bridge converter. Conventional transformers are widely applied in electric power systems for performing many functions, such as electric isolation, voltage level transformation, noise decoupling, etc. However, these conventional transformers have larger volume, heavy weight which are becoming unacceptable nowadays; therefore, newer technologies are highly expected. High-frequency operated solid-state transformers are one of solutions. By increasing the operating frequency, the volume and weight of the transformer can be reduced; on the other hand, phase-shift modulation can be used to regulate the power flow in either direction. However, the use of high-frequency operation induces unwanted high-frequency components, which claim for second-order low pass filters on both input and output sides to filter out these unwanted ingredients. Therefore, carefulness on design is required in order not to lose the objective of reducing weight and volume.
A prototype circuit based on ac-ac dual-active-bridge converter has been built and tested in lab successfully. The circuit is with rated of 220 Vrms input voltage, 220 Vrms output voltage and 2 kW output power. A digital-signal processor is used to realize the control of this circuit. The measured efficiency is higher than 92% within the overall range of load conditions.

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