本論文主要研製「電流饋入推挽式轉換器」，此電路為雙級式電源供應器，前級為降壓式轉換器，功能為調節輸出電壓，而後級為推挽式轉換器，提供電氣隔離與電壓轉換功能。此架構非常適合應用於低電壓大電流之負載及廣泛的輸入電壓。本論文首先探討此電路之特性與優缺點，其次是分析推挽式轉換器操作於責任週期50%之工作原理，並做穩態分析。最後實作一部「電流饋入推挽式轉換器」，轉換器之輸入電壓為36~72V，輸出為2.5V/70A，當輸入電壓為48V時，滿載效率為82.3%；當輸出電流為20A時，轉換器之效率可達91.3%。

This thesis mainly studies and implements a current-fed push-pull converter, which is two-stage power supply. The first stage is a buck converter with the output voltage regulator function, and the second is a push-pull converter with the electrical isolation and step-down function. The topology is very suitable for low-output-voltage, high-output-current applications with a wide input voltage range. First, the characteristics of the topology are discussed, and the operation principle of the push-pull converter with a 50% duty cycle is studied in this thesis. Finally, a current-fed push-pull buck converter with a 36~72VDC input voltage range and 1.5V/70A output is performed. The experimental results show that efficiency of the proposed converter is 82.3% at full load condition and the maximum efficiency is 91.3% at 20A output current.

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