結合超電容於太陽能系統以提升低日照功率轉換效率

Solar power system with supercapacitors for improvement conversion at low irradiance

李嘉晏(Jia-Yan Li)

指導教授 ： 葉哲良

國立清華大學/工學院/微機電工程研究所/碩士(2007年)

摘要

太陽能電池受到天氣日照的影響，不是一個穩定的電能來源，在不同日照強度會改變太陽能電池輸出功率與電壓的特性，造成在不同日照下，太陽能電池無法維持最大功率輸出，造成功率上的損失。以往為了讓太陽能電池在不同日照下輸出最大功率，會在太陽能電池與負載間加入具有直流變壓器的最大功率追蹤器電路，透過監控太陽能電池或是負載端的電壓、電流，在經邏輯運算比較前後取樣時間的輸出功率的變化，作為調整直流變壓器的變壓倍率與太陽能電池操作電壓位置的依據。本論文提出另外一種不需要透過直流變壓器控制太陽能電池操作電壓位置，經由超電容器與比較放大器，簡單邏輯控制及可以維持太陽能電池輸出最大功率附近操作位置。透過超級電容器以儲存與補償兩階段管理太陽能電池輸出電能與操作電壓，尤其可以改善在低日照時太陽能電池輸出功率的效率。

關鍵字

太陽能 ； 低日照 ； 超級電容器

並列摘要

Solar cells’ current - voltage (I-V) characteristic is affected by the weather irradiance. To obtain the maximum power output of solar cells, the DC converter circuit with MPPT (Maximum Power Point Tracking) system was typically implemented between solar cells and load. This research proposed another kind of solar energy system that uses supercapacitor for power management.Supercapacitors use two operation modes, storing and compensating solar energy to control solar cells’operation point near maximum power point. The proposed system can improve solar cells output power efficiency especially at low irradiance.

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