摘要
功率因數修正(Power Factor Correction, PFC)線路已廣泛地使用在各種電源供應器，用以改善電源供應器的輸入電流諧波失真以及功率因數。現今世界上對於環保以及節能的要求日趨嚴謹，因此，要提升電源供應器整體效率，PFC電路的效率提升也是目前研究的重心。 本文提出一被動式ZCS PFC線路架構，利用可飽合耦合電感的特性，當PFC電路在穩態工作時，可飽合耦合電感呈現飽和短路特性使電感損失降到最低。同時在PFC電路功率開關導通時，可飽合耦合電感離開飽和狀態呈現耦合電感特性，抑制並吸收PFC線路中升壓二極體的逆向回復電流能量，使升壓二極體能夠工作在零電流截止工作條件，同時降低主功率開關的導通切換損失。另外當PFC電路功率開關截止升壓二極體導通前，ZCS電路將已經吸收的逆向回復電流能量重新釋放到輸出端，以達到提高PFC電路工作效率的目的。
並列摘要
The PFC (Power Factor Correction) circuit is widely used in various power supplies so as to reduce the corresponding harmonic distortion and to increase power factor. Up to now, the environment protection and the energy saving are getting more and more attractive in the world. Consequently, improvement in the overall efficiency of the power supply is indispensable, and hence enhancement of the efficiency of the PFC circuit is an important research topic. Consequently, a passive ZCS (Zero Current Switching) PFC circuit topology is presented herein, which is used on the characteristics of the saturable coupling inductor. As the PFC circuit works in the steady state, such an inductor is short-circuited, so as to make the loss in this inductor as minimum as possible. On the other hand, as the power switch of the PFC circuit is switched on, the saturable coupling inductor gets far away from the saturated condition and is represented as an inductor, so as to reduce the reverse recovery current of the boost diode and to absorb the portion of the energy created from this current. By doing so, the boost diode can be switched off under ZCS, and at the same time the switching loss of the main power switch can be reduced. Besides, before the main power switch is turned off and the boost diode is turned on, the ZCS circuit releases this stored energy to the output, so as to further upgrade the efficiency of the PFC circuit.