整合式高功因降升壓/返馳式發光二極體驅動電路

Abstract

本論文提出一全新之單級高功因交流轉直流發光二極體驅動電路架構，將降升壓式功因修正電路(Buck-Boost PFC)及返馳式轉換器(Flyback Converter)整合成單級架構，同時達到低成本、小體積、高效率、高功率因數、低總諧波失真(Total-Harmonic-Distortion)並可提供一穩定輸出電流驅動發光二極體。本論文透過巧妙安排各電路元件位置，形成一漏感能量回收路徑，可回收返馳式變壓器之漏感能量，提升電路效率。此外，本論文也針對所提出之單級高功因之交流轉直流發光二極體驅動電路設計兩種控制電路，一為傳統之二次側回授搭配電壓模式控制，另一為新型之一次側回授搭配電流模式控制。本論文提出之新型一次側回授控制技術，改良了傳統式一次側回授控制之回授路徑設計，可提升控制電路之抗干擾能力。另一方面，本論文不僅透過理論分析所提出電路，並推導相關操作模式、等效電路及設計數學式，亦利用實驗驗證理論分析之結果。

This dissertation proposes a novel single-stage high-power-factor AC/DC light-emitting-diode (LED) driver circuit, which integrates a buck-boost power factor corrector (PFC) with a flyback DC/DC converter. A recycling path is built to recover the leakage inductive energy. In this way, the presented circuit can provide not only high power factor and low total harmonic distortion (THD), but also high conversion efficiency and low switching voltage spikes. On the other hand, this dissertation also proposes two control circuits for the proposed driver circuit, one is the voltage-mode control integrates with a secondary-side regulation (SSR), and the other is the current-mode control merges with a novel primary-side regulation (PSR). The proposed PSR technique can enhance the noise immunity of the current-mode control. Besides the theoretical analysis, the proposed driver and control circuits are verified by the experiment.