具高功率因數與低總諧波失真之AC LED驅動器之效率改善

Efficiency Improvement of AC LED Driver with High PF and Low THD

房玉堂(Yu-Tang Fang)

指導教授 ： 胡國英

國立臺北科技大學/電資學院/電機工程系研究所/碩士(2012年)

摘要

本論文採用一具高功率因數與低總諧波失真之AC LED驅動器，於輸入橋式整流後端加入一切換式LED模組，並以場效可規劃邏輯閘陣列(Field Programmable Gate Array, FPGA)做為控制核心，主要乃針對此驅動器之效率來進行改善。其切換式LED模組係由數串LED串列所構成，而各LED串列各自具有一由金氧半場效電晶體(Metal Oxide Semiconductor Field Effect Transistor, MOSFET)所構成之開關。當切換式LED模組上之開關導通時，該串LED串列相當於被短路而不導通發亮；當開關截止時，多餘的輸入電壓將跨至該LED串列上使其導通發亮，以減少多餘的輸入電壓跨在BJT電流源的集極與射極間所造成之不必要的功率損耗，以提高驅動器的整體效率。

關鍵字

AC LED驅動器 ； 功率因數 ； 總諧波失真 ； 效率 ； 切換式LED模組 ； 場效可規劃邏輯閘陣列

並列摘要

In this thesis, one AC LED driver with high PF and low THD is adopted, which is added with the proposed switched LED module and is controlled based on the field programmable gate array (FPGA). By doing so, the efficiency of such an AC LED driver can be improved greatly. This switched LED module is constructed by several LED strings, which have individual series-connected MOSFET switches. As the switch of the switched LED module is turned on, the corresponding LED string is short-circuited and hence is not conducted, whereas as the switch of the switched LED module is turned off, the corresponding LED string is conducted due to the redundant input voltage across this LED string. By doing so, the redundant input voltage across between the collector and the emitter of the BJT current source can be reduced, that is, the unwanted power dissipation in the BJT current source can be decreased, so as to upgrade the efficiency of the overall system.

並列關鍵字

AC LED Driver ； Power Factor ； Total Harmonic Distortion ； Efficiency ； Switched LED Module ； Field Programmable Gate Array

參考文獻

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