由於有限石化能源及溫室效應之影響，使得各國政府積極發展及推動再生能源，而其中太陽光伏發電系統由於太陽能取之不盡、用之不竭與無震動噪音之優點，所以近年來始終持續很高的成長率。然而由於太陽能電池輸出端電壓會隨日照量強弱而有高低變化，需要一轉換器調控以擷取最大輸出功率。由於邱克轉換器具有可昇/降壓、輸入/輸出電流連續等優點，故本文選用其作為太陽能電池之最大輸出功率控制轉換器。其次，針對切換式電力轉換器固有之電流漣波會造成太陽能電池輸出功率無法保持運轉於最大輸出功率點、導致其平均輸出功率減少等問題，本論文更深入一層探討轉換器之電流漣波對於太陽能光伏系統所造成的具體量化影響，並提出漣波消除技術以解決上述困境。
基本上，本論文的主要貢獻有四點：第一點，吾人以精確數學模式，探討電流漣波大小所造成太陽能電池輸出功率的量化損失。第二點，本文首先提出一種主動式漣波消除技術，透過輔助電路的設計、以補償漣波之方式使轉換器之輸入與輸出電流達到零漣波效果，此方法能有效減小轉換器儲能電感、且不需要增加額外控制與迴授電路。此外，本文更基於此主動漣波補償的概念進一步研發出更精簡的被動式漣波消除電路，使得邱克轉換器在工作點改變的情形下亦能維持零輸入電流漣波，並精確擷取太陽能電池之最大輸出功率。第三點，針對所提轉換器推導其數學模型，以利迴授控制器之設計，並以電路模擬軟體驗證其數學模型之正確性。第四點，本文並實際製作出一輸入電壓為24V至34V、輸出電壓為19V以及額定功率為90W的雛型系統。實測結果顯示，本文所研製轉換器可有效減小傳統邱克轉換器之輸入電流漣波最高約達98%，其漣波大小可降至30mA；同時在日照強度為0.8 kW/m^2、太陽能板表面溫度為50℃之測試條件下，本論文所提轉換器可使太陽能電池之平均輸出功率約達75W，相較於原邱克轉換器可增加約7%平均功率輸出。

Due to the limited fossil energy and greenhouse effect, more and more countries are devoting to development and promotion of renewable energy sources. Among the various renewable energy sources, solar energy has the advantages of being inexhaustible and noiseless. Hence, installation of photovoltaic (PV) power generation systems keeps a rather high growing rate in recent years. However, the output voltage of the solar cells changes rapidly with the insolation. Hence, a switching power converter is required as a regulator for achieving the maximum output power of the PV power generation system. In this thesis, Cuk converter is adopted because of its step up/down capability and nonpulsating input/output current feature. However, the inherent current ripple of switching power converter indeed may cause significant impact on the output power. Hence, the major objective of this thesis is focused on the further study of the quantitative output power reduction effect of the input current ripple of PV systems as well as proposing ripple cancelling techniques to solve the above dilemmas.
Basically, the contributions of this thesis can be summarized as follows. First, the power reduction caused by the current ripple of solar cells is analyzed through an accurate mathematical model. Second, an active ripple cancelling technique is proposed to eliminate the current ripple of the conventional Cuk converter effectively. By proper design of an auxiliary circuit, zero input and output current ripples can be achieved. The proposed method does not require an extra control and feedback circuit. Furthermore, based on the ripple cancelling concept, a simple passive ripple cancel technique is proposed. It turns out that the maximum output power of the PV system can now be fully extracted. Third, both DC and AC models of the proposed zero input current ripple Cuk converter are derived for convenient closed-loop controller design. Also, simulation results are made to verify the accuracy of the models. Finally, a 90W, 24V~34V input, 19V output laboratory prototype is constructed to verify the effectiveness of the proposed converter. It is seen that the resulting peak to peak input current ripple is about 2% of the current ripple due to the conventional Cuk converter. Furthermore, at 0.8 kW/m^2 insolation, 50℃ test condition, it is seen that the average output power of the PV array can reach 75W by using the proposed technique. In other words, this amounts to an increase of 7% averaged output power as compared with the conventional Cuk converter.

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