本論文主要研製一台輸出規格為 500W/12 V、數位控制雙變壓器全橋串聯諧振式直流-直流轉換器，其變壓器一次側全橋開關導通時具有零電壓切換的特性，可以用來減少切換損失。本文一開始先探討全橋串聯諧振轉換器與全橋LLC型式的串聯諧振轉換器的理論基礎，以及分析各個階段的電路動作原理和等效電路推導，並利用數學軟體 Mathcad 和推導出來的諧振槽轉移函數，來繪製不同品質因數 Q、電感比值 K、特性阻抗Z0、諧振電感Lr、變壓器圈數比 n在諧振槽增益曲線上的變化趨勢，以利設計轉換器諧振槽時，能掌握參數變化對於諧振槽的影響。
最後實作出一台輸出規格為 500W/12 V 之數位控制雙變壓器全橋串聯諧振式直流-直流轉換器，並利用德州儀器所開發的數位信號處理器 TMS320F28035 來實現數位控制，將實測結果和理論相互印證。

This thesis presents the study and implementation of a digitally- controlled two-transformer full-bridge series-resonant converter. The output specifications of this circuit are an output voltage of 12 V and an output current of 42 A. The primary-side switches possess the turn-on with zero-voltage switching ( ZVS ) in order reduce the switching losses. Firstly, the analysis of basic circuit theories for full-bridge SRC and full-bridge LLC are discussed. The operation principles and equivalent circuits of different working intervals of SRC and LLC are also discussed and derived, respectively. Then, according to the derived transfer function of the resonant tank, a mathematical software Mathcad is used to plot the different parameter curves for quality factor ( Q ), inductance ratio ( K ), characteristic impedance ( Z0), resonant inductance ( Lr ), transformer turns ratio ( n ) on the frequency response of the voltage gain of resonant tank.
Finally, a 500-W prototype circuit of a two-transformer full-bridge series-resonant converter was implemented, and control stage of the prototype circuit was realized by using Texas Instruments DSP chip TMS320F28035. Theoretical analyses are verified with the experimental results.

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