具耦合電感之單級非對稱半橋功因校正轉換器

Abstract

本論文提出一個具耦合電感之單級非對稱半橋功因校正轉換器。此轉換器是將一個非對稱半橋轉換器與一組耦合電感及一個阻隔二極體做整合所發展而來。透過此組耦合電感及此阻隔二極體，本論文所提出之轉換器可達成具buck-boost型功率因數校正功能之單級交流直流電能轉換。因此，此轉換器可在不使用額外的功率開關及控制電路的情況下，在通用輸入電壓條件下達成趨近於一之功率因數及低總諧波失真。另外，此轉換器之兩個功率開關在通用輸入電壓條件下皆可達成零電壓切換以減少切換損失。因此，此轉換器可提升交流直流轉換器之整體效率及功率密度。故，本論文所提出之轉換器在通用輸入電壓條件下具有功率因數趨近於一、總諧波失真低、元件數量少、控制策略簡單，以及轉換效率高之特點。最後，透過電腦模擬及實作一台100W之原型電路，來驗證本論文所提出的具耦合電感之單級非對稱半橋功因校正轉換器之概念及功能。

A single-stage asymmetrical half-bridge (AHB) power factor correction (PFC) converter with coupled inductors is proposed in this thesis. The proposed converter is developed from the combination of an AHB converter and a set of coupled inductors along with a blocking diode. By applying the set of coupled inductors and the blocking diode, the proposed converter can achieve single-stage AC-DC conversion with the buck-boost type PFC. Hence, the proposed converter can provide near unity power factor (PF) and low total harmonic distortion (THD) under the universal input condition without using any extra power switch and control circuit. In addition, the proposed converter can achieve zero-voltage switching (ZVS) operation for both of the power switches under the universal input condition to reduce switching loss. As a result, the proposed converter can improve the overall conversion efficiency and power density of the AC-DC converter. Therefore, the proposed converter features the advantages of near unity PF, low THD, little component counts, simple control strategy, and high circuit efficiency under the universal input condition. Computer simulation and hardware experimental results of a 100W prototype circuit are presented to verify the effectiveness of the proposed single-stage AHB PFC converter with coupled inductors.