在功因校正電源轉換器之設計上，必須謹慎處理由逆向恢復電流所導致的硬切換消耗。目前已經有兩種解決硬切換消耗問題的方式被提出來。一者是被動軟切換方法，再者是主動軟切換方法。在實務上，被動軟切換方法已經廣泛應用於工業上。因為有簡單、低成本和可靠的優點。雖然被動軟切換方法擁有諸多優點，仍然存在著一些缺陷，有待改善。本文研製一改良式零電流切換方法，不但解決了硬切換消耗問題，並且同時改善被動軟切換方法的缺點。特別是利用飽和電感和一分支電路來取代零電流切換電路中的電感器。這種提議的方式使被動軟切換電路達到最佳化，而且改善了已知的缺點。 在本文中除詳細介紹改良式零電流切換功因校正器的工作原理外，並經由實際的電路實作結果跟一般被動軟切換及硬切換功因校正器做比較。證明出本實驗電路的可行性，而且改善了大部份的軟切換方式之缺點。 In the PFC converter design must carefully deal with the hard switching losses due to the recovery current of boost diode. There are two approaches had proposed to solve the hard switching losses issue. One is passive soft switching method and the other is active soft switching method. Practically, the passive soft switching method has been used more widely in industry, because of it has simple, low cost, and reliable. Although, the passive soft switching method has more merits but it still exists some drawbacks that need to be improved. This thesis proposes the improved zero current switching method not only to solve the hard switching issue but also to improve drawbacks of the passive soft switching method. Especially, the saturable core (Amorphous core) and a branch circuit are proposed to substitute the fixed inductor in ZCS circuit. This proposal optimizes the passive soft switching circuit and improves many drawbacks. In this thesis, besides the principle of operation is introduced in detail, the experimental results of the real implementation is compared with the hard switching PFC converter as well as others passive soft switching. According to experimental results, this proposed improved zero current switching method is proved feasible, and also improves the most of drawbacks of passive soft switching methods.
