- 學位論文
閉迴路降昇壓式轉換器發光二極體驅動電路之設計
Design of Closed-Loop Buck-Boost Converter for LED Driver Circuit
摘要
近來因地球暖化現象加劇，各國紛紛提出節能減碳政策，積極尋求潔淨能源，其中LED在照明設備中，具有省電、環保、耐用等優點的設備之ㄧ。目前LED產品與一般照明設備價格仍偏高，本論文提出簡單之電路以驅動LED照明，使其相關產品價格降低，近而取代傳統之照明器具。 本論文主要探討具有昇壓與降壓功能的降昇壓轉換器，選用LED規格之順向偏壓為3.1~4.3V、順向電流為0.7A。而電路所驅動LED為12顆串聯之3W白光LED，單一LED額定電壓為4V，電流為0.6A，以交流電110V經橋氏整流後，再輸入直流電至驅動LED之電路，然後操作於降昇壓之連續電流模式並以Isspice輔助軟體模擬出結果並比較。 因LED使用時，只有15%~25%電能轉換成光能，且內阻會隨著溫度而改變，故以閉迴路電壓系統控制模式驅動LED。本論文首先完成驅動電路與降昇壓電路架構及工作模式，以狀態空間平均法導出穩壓控制器之轉移函數所需最短穩壓時間，並利用MATLAB加以模擬，達到控制器穩態要求。最後，由實驗結果證明可得知LED整體照明系統之功率因數為1。而設計之控制器能確實將輸出電壓控制於48V。
並列摘要
In recent years, since the phenomenon of accelerated global warming, the countries have proposed carbon reduction policies and actively seek clean energy. LED lighting devices which to be with saving energy, environmental protection, durable one of the advantages of the device. At present, the prices of general LED lighting products are still expensive. To instead of the conventional lighting apparatus, a simple driver circuit of the LED lighting proposed in this thesis to reduce the price of related products. In this thesis, the driver with Buck-Boost converter would be study. The specifications of LED used which the voltage and current ratings is 3.1~4.3V and 0.7A. The proposed circuit would drive the 3W of 12 series white light LED. The voltage operated in 4V and 0.6A for each LED, to AC 110V rectified by the bridge, then enter the direct current to drive LED of the circuit, And it would be operated with continue mode of Buck-Boost. these results simulated by the Isspice software to be compared. Because of the LED use, only 15% to 25% energy converted into light, various resistance by the temperature, the closed-loop controller of voltage would be used in the circuit proposed. The circuit scheme and operation mode would be done first in this thesis. To make use of the state-space averaging method to export the shortest time required of the stabilizer, and be simulated by the MATLAB required to achieve steady-state controller. Finally, The results showof the LED lighting fixture can achieve a high power factor 1. it is feasible from the experimental results, and is available at the output voltage controlled 48V.