- 學位論文
應用串聯輸入並聯輸出雙LLC共振轉換電路之高功因LED驅動器
A High-Power-Factor LED Driver with Series-Input Parallel-Output Dual LLC Resonant Conversion Circuits
摘要
本文提出利用兩組無橋單級高功因諧振式轉換器，以串聯型式連接，並以交錯式交互操作，作為高效率LED照明驅動器。串聯連接使每一無橋單級高功因諧振式轉換器之輸入電壓減半，使電路中的直流鏈電壓也具有減半之效果，達到降低電路元件之電壓應力之優點。交錯式的功因修正電流具有降低電源電流的高頻諧波成分，達到更佳的功率因數修正效果。本文使用的無橋單級高功因諧振式轉換器，同時達成無橋電路的功因修正與半橋LLC諧振式轉換器的直流轉換之功能。結合無橋功因修正電路與LLC諧振轉換器高效率之特點，電路效率可更進一步的提升。本文最終設計出輸入電壓為市電220伏特之200瓦LED驅動電路，經實驗結果得出，滿載時效率達到94.2%，功率因數高於0.99，電路最高效率為96.6%。
並列摘要
In this thesis, a high efficiency LED driver is proposed by series two bridgeless single-stage high power factor resonant converters with interleaved control being used. The series connection makes each single-stage converter experience half the input voltage and, accordingly, halves the DC link voltage, thus reducing the voltage stress on the circuit components. With the interleaved control being used, the power factor correction currents of the upper and lower single-stage converter will appear in complimentary way which can effectively reduce the high frequency harmonic components and, therefore, improve the power factor. The proposed bridgeless single-stage resonant converter can accomplish power factor correction and decrease the amount of component usage by the design of bridgeless power factor correction stage and promote the conversion efficiency due to the design of the half-bridge LLC resonant converter. The integrated single-stage topology further lowers the complexity the circuit structure. Finally, a prototype 200W LED driver with 220V input voltage is implemented and realized. The experimental measurements reveal that the full load efficiency can reach 94.2% while the power factor exceeds 0.99. In the dimmable range, the maximum circuit efficiency can reach 96.6%.