【正文】 不是能夠讓光電組件產(chǎn)生最大可用電能的理想工作電壓。 C 電池溫度和 1000w/m2 日照強度的標準測試條件下的電流 /電壓曲線。由于 75W 的模塊被鉗制在 12V 電壓下工作，傳統(tǒng)的控制器人為的限制了產(chǎn)生的電能大約在 53W 左右 。這個例子中模塊產(chǎn)生最大功率時的電壓（ VMP）是 17V。一個高效率的 DC/DC 電力轉(zhuǎn)換器轉(zhuǎn)換在控制器輸入端的 17V 模塊電壓為輸出端電池的電壓。 VBATTERY x IMODULE 或 17V 247。通過收獲那些本來會被傳統(tǒng)控制器浪費的電能并將它轉(zhuǎn)化為可用的充電電流， 將增加 的充電電流或達到 42%的增量。 有用充電電流增量隨工作條件的變化而變化。降低光伏電池單元的溫度傾向于產(chǎn)生更高的最大功率點電壓（ VMP） ，也就更大的充電電流增量。 C 時的最大功率點電壓高于 17V 也同樣能夠產(chǎn)生更大的充電電流，因為此時實際的最大功率點電壓將比蓄電池電壓更高。在適當?shù)牡蜏貤l件和典型電池條件下，人們可以看到充電電流將增加 10 – 25%。寒 冷氣候下的客戶報道說充電電流甚至超過了 40%的增幅。在寒冷環(huán)境下，白天很短暫，太陽離地平線低 ,蓄電池將被更完全的放電。 為什么要最大功率點跟蹤（ MPPT） ? MPPT 附加在太陽能電池板上使它工作在最大功率點上。它要求將電路設(shè)計得高效率、重量輕、體積小、高可靠性。而這些參數(shù)在白天總是變化的，太陽能電池、太陽能電池板輸出特性也各不相同。如果將太陽能電池板直接連接到電池，系統(tǒng)會產(chǎn)生功耗，因為在某些時段太陽能電池板的運行特性將隨環(huán)境條件的改變而改變?；诖?，在太陽能電池板和電池之間加設(shè)電池最大功率點跟蹤電路。 充電控制器又出現(xiàn)了新的特點。它在一定條件下從你的光伏陣列攝取額外的電能。MPPT 的功能類似于汽車的傳動裝置，當傳動裝置運轉(zhuǎn)在錯誤的檔位，車輪得不到最大的動力。傳動裝置的作用是連接引擎和車輪使引擎不管在任何速度，任何地形都運行在一個最佳的轉(zhuǎn)速范圍。它的電壓類似于引擎速度。 VPP 隨陽光強度和太陽能電池溫度變化，蓄電池的電壓類似汽車車輪的速度，它會隨電池充電狀況 ,以及系統(tǒng)負載（任何電器和燈泡等等）而變化。為了對電池充電 (增加它的電壓 )，光電組件必須提供高于電池電壓的充電電壓。所以 ,為了這方面的安全 ,典型的光電組件的 VPP 在 25℃光電池單元溫度時測量大約 17v 左右。 然而 ,在一個非常寒冷的日子 ,它可以上升到 18V!在 VPP 遠遠高于電池電壓的情況下會發(fā)生什么樣的事呢？ 模塊電壓拉低到低于理想的電壓?，F(xiàn)在，讓我們再作比喻，汽車的傳動裝置改變汽車傳輸速度及扭矩比例，低擋時，車輪的速度降低，扭矩加大，對不對？同樣， MPPT 改變送往電池的電壓和電流的比例，以提供最大功率。此外，它像一個自動傳動裝置一樣。 在現(xiàn)實世界 MPPT 有什么好處？這取決于你的光伏陣列，你的氣候，和你的季節(jié)性負荷特點。在炎熱的天氣，情況可能并非如此，除非電池欠充電。如果你能源利用最大的時候是冬季 (最典型的家庭 )，有寒冷的冬天，那么在你最需要能量的時候你可以得到可靠的能源供應(yīng)！ （二） Enengy or Solar Enegry Energy means the power which does work and drives machines. All living things (including humans) rely on the sun as a source of energy. Coal, petroleum, and natural gas are energy sources available today because anisms in the past captured unlight energy and stored it in the plex anic molecules that made up their bodies, which were then pressed and concentrated. With the development of society, alarge of energy sources have been used,such as coal, petroleum, natural gas,geothermal energy, nuclear fission power, nuclear fusion power, solar energy, and Hydrogen gas. however, under the circumstances, the quantity of energy source is limited. unlimited usage of energy source results in energy crisis. At present, most of the energy consumed by humans is produced from fossi fuels. The greatest recoverable fossil is in the form of coal and lignite. Although world coal resources are enomous and potentially can fill energy needs for a century or two, their utilization is limited by environmental disruption from mining and emissions of carbon dioxide and sulfur dioxide. These would bee intolerable long before coal resources were exhausted. Only a small percentage of coal and lignite has been utilized to date, whereas much of the recoverable petroleum and natural gas has already been consumed. Petroleum has several characteristics that make it superior to coal as a source of energy. Its extraction causes less environmental damage than does coal mining. It is a more concentrated source of energy than coal, and it burns with less pollution, and it can be moved easily through pipes. These characteristics make it an ideal fuel for automobiles. Since first mercial oil well in 1859, somewhat more than 100 million barrels of oil have been produced in the United States, most of it in recent years. In 1990 world petroleum consumption was at a rate of about 65 million barrels per day. Projected use of petroleum and natural gas indicates rapid depletion. Alaskan oil can help the petroleum supply only temporarily. Peak world petroleum resources production will be reached within a few years. Since the first energy crisis of 19731974, some concrete actions have even taken place. However, the severalfold increase in crude oil prices since 1973 has extacted a toll. In the . and other industrialized nations, the economy has been plagued by inflation, recession, unemployment, and obsolescence of industrial equipment. The economies of some petroleumdeficient developing countries have been devastated by energy prices. Energy crisis was acpanied by