新型單級LED路燈驅動電路之研製

在全球節能減碳熱潮下，具備體積小、亮度高且以半導體科技為基礎的LED固態照明，是在日常照明應用中最熱門的節能方案。傳統LED路燈照明驅動電路為兩級式架構，由前級具有功因修正功能的交錯式升壓型轉換器與後級半橋式LLC諧振轉換器組成，或是具有功因修正功能的升壓型轉換器與後級半橋式LLC諧振轉換器所構成。兩種傳統LED路燈驅動電路的電路元件數目與成本較多，且因為輸入能量經過兩級功率轉換導致電路效率不高。因此，本論文研製具耦合電感之新型單級LED驅動電路，整合具耦合電感之交錯式降壓轉換器與半橋式LC串聯諧振串接全波整流器成為單一級的電路架構，透過設計耦合電感操作在不連續導通模式，以達到功因修正的功能。此外，設計半橋式LC串聯諧振電路之參數使諧振槽路呈現電感性負載，讓功率開關具有零電壓切換(ZVS)的功能，減少切換損耗，提高電路整體的效率。本論文已完成單級LED路燈驅動電路的動作模式分析，以及165W雛型電路的研製。藉由實測電路波形結果得知，在110伏特的交流輸入電壓下，本論文的單級LED路燈驅動電路具有功因大於0.98、輸入電流總諧波失真因數小於3%、效率大於89%、輸出電壓漣波率小於6%、輸出電流連波率小於7%等特點。

關鍵字

驅動電路；功因修正；發光二極體；路燈

並列摘要

Under the global energy saving and carbon reduction boom, LED solid-state lighting with small size, high brightness and semiconductor technology-based is the most popular energy-saving solution in daily lighting applications. The traditional LED streetlight driver circuit is a two-stage topology, consisting of an interleaved boost converter with power factor correction function at the first stage and a half-bridge LLC resonant converter at the second stage, or boost converter with power factor correction function at the first stage and a half-bridge LLC resonant converter at the second stage. The disadvantages of the two traditional LED streetlight drivers are the large number of circuit components and the cost, and because the input energy undergoes two-stage power conversion, the circuit efficiency is not high. Therefore, this thesis develops a new single-stage LED streetlight driver circuit with coupled inductors, integrating the interleaved buck converter with coupled inductors and the half-bridge LC series-resonant converter with a full-wave rectifier into a single-stage circuit topology. By designing the coupled inductors inside the streetlight driver at discontinuous-conduction mode, the function of power factor correction is achieved. In addition, the resonant tank in the half-bridge LC series-resonant converter is designed to resemble an inductive load, so that the power switches have the function of zero voltage switching (ZVS), reducing the switching loss and improving the overall efficiency of the circuit. Analysis of operational modes in the single-stage LED streetlight driver circuit and the development of the 165W prototype circuit are completed in this thesis. According to the measured circuit waveform results, under the AC input voltage of 110 volts, a power factor greater than 0.98, an input current total harmonic distortion factor less than 3%, an efficiency greater than 89%, an output voltage ripple rate less than 6%, and an output current ripple less than 7% are obtained in the single-stage LED streetlight driver circuit.