現今市面上許多產品具備儲能系統，無論是再生能源系統、工業應用或車用系統，其輸出電壓普遍高於電池額定電壓。為了將能量儲存於電池上，必須將輸出電壓降至電池之額定電壓。本文提出一主動箝位降壓順向式轉換器且具有寬零電壓導通功能，以應用於電池充電。本論文利用儲能電感與漏電感對開關上的寄生電容儲能與釋能，在變壓器一次側增加簡單的主動式箝位電路，改善輸入高壓所產生的電壓應力的問題，且不需增加第三側繞組，增加轉換器整體效率。本論文實現輸入為 150-250 VDC、輸出12VDC且額定功率為200W之實體電路，並以模擬及實作結果驗證所提轉換器之理論與可行性。
關鍵字：主動箝位、順向式轉換器、零電壓導通

Nowadays, the renewable energy, industrial and vehicle systems usually are needed the energy storage system to connect the output terminal. Generally, the output voltages of these systems are higher than energy storage systems. Thus, these systems need high step-down gain to meet the requirements for the battery charging systems. This thesis presents a ZVS active-clamped forward converter for battery charging applications. In the proposed topology, the magnetizing and leakage inductor can be employed to resonate with the parallel capacitors of the MOSFETs. Since the input voltage is relatively high, the voltage stress of the MOSFET in forward converter cannot be restricted. In this case, a ZVS active-clamp forward converter can be chosen as an alternative to limit the semiconductor voltage stress. Thus, a simple active-clamp circuit is added in the primary winding of the transformer. Furthermore, the third winding of the transformer can be saved and the efficiency can be improved effectively with including the active-clamp circuit. A 200 W, 12 VDC output voltage active-clamp forward converter with an input voltage various form 150 to 250 VDC prototype is designed and implemented to verify the effectiveness of the proposed converter.
Keywords: active-clamp, Forward converter , zero-voltage turn- on

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