太陽能畢業(yè)設(shè)計外文翻譯

1、<p>　?。ㄒ唬?What is Maximum Power Point Tracking (MPPT) and How Does it Work? </p><p>　　Photovoltaic (PV) generation is becoming increasingly important as a renewable source since it offers many advan

2、tages such as incurring no fuel costs, not being polluting, requiring little maintenance, and emitting no noise, among others. PV modules still have relatively low conversion efficiency; therefore, controlling maximum po

3、wer point tracking (MPPT) for the solar array is essential in a PV system. </p><p>　　The amount of power generated by a PV depends on the operating voltage of the array. A PV’s maximum power point (MPP) var

4、ies with solar insulation and temperature. Its V-I and V-P characteristic curves specify a unique operating point at which maximum possible power is delivered. At the MPP, the PV operates at its highest efficiency. Ther

5、efore, many methods have been developed to determine MPPT. </p><p>　　Maximum Power Point Tracking, frequently referred to as MPPT, is an electronic system that operates the Photovoltaic (PV) modules in a ma

6、nner that allows the modules to produce all the power they are capable of. MPPT is not a mechanical tracking system that “physically moves” the modules to make them point more directly at the sun. MPPT is a fully electr

7、onic system that varies the electrical operating point of the modules so that the modules are able to deliver maximum available power. Additio</p><p>　　To understand how MPPT works, let’s first consider the

8、 operation of a conventional (non-MPPT) charge controller. When a conventional controller is charging a discharged battery, it simply connects the modules directly to the battery. This forces the modules to operate at ba

9、ttery voltage, typically not the ideal operating voltage at which the modules are able to produce their maximum available power. The PV Module Power/Voltage/Current graph shows the traditional Current/Voltage curve for a

10、 typi</p><p>　　Rather than simply connecting the module to the battery, the patented MPPT system in a Solar Boost charge controller calculates the voltage at which the module is able to produce maximum power

11、. In this example the maximum power voltage of the module (VMP) is 17V. The MPPT system then operates the modules at 17V to extract the full 75W, regardless of present battery voltage. A high efficiency DC-to-DC power co

12、nverter converts the 17V module voltage at the controller input to battery voltage at th</p><p>　　Actual charge current increase varies with operating conditions. As shown above, the greater the difference

13、between PV module maximum power voltage VMP and battery voltage, the greater the charge current increase will be. Cooler PV module cell temperatures tend to produce higher VMP and therefore greater charge current increas

14、e. This is because VMP and available power increase as module cell temperature decreases as shown in the PV Module Temperature Performance graph. Modules with a 25°C VMP r</p><p>　　WHY MPPT? </p>

15、<p>　　MPPT loads solar panel that it operates at the maximum power point. MPPT is a DC-DC converter that uses high frequency switching and control algorithm. It is desired to design the circuit at high efficient,

16、light weight, small size, and reliable for the event. Solar cells are dependent on environment conditions like temperature, sun light, and load voltage. While this parameters always changing daytime, solar cell or solar

17、panel output characteristics vary also. Some hours photovoltaic system m</p><p>　　INCREASE SOLAR CHARGING WITH AN MPPT POWER TRACKING CHARGE CONTROLLER </p><p>　　A new feature is showing up in

18、 charge controllers. It's called maximum power point tracking (MPPT). It extracts additional power from your PV array, under certain conditions. This article explains the process by a mechanical analogy, for people

19、who do not understand basic electricity.The function of a MPPT is analogous to the transmission in a car. When the transmission is in the wrong gear, the wheels do not receive maximum power. That's because the engine

20、 is running either slower or faster th</p><p>　　Let's compare a PV module to a car engine. Its voltage is analogous to engine speed. Its ideal voltage is that at which it can put out maximum power. This

21、is called its maximum power point. (It's also called peak power voltage, abbreviated Vpp). Vpp varies with sunlight intensity and with solar cell temperature. The voltage of the battery is analogous to the speed of t

22、he car's wheels. It varies with battery state of charge, and with the loads on the system (any appliances and lights that may be </p><p>　　What advantage does MPPT give in the real world? That depends on

23、 your array, your climate, and your seasonal load pattern. It gives you an effective current boost only when the Vpp is more than about 1V higher than the battery voltage. In hot weather, this may not be the case unless

24、the batteries are low in charge. In cold weather however, the Vpp can rise to 18V. If your energy use is greatest in the winter (typical in most homes) and you have cold winter weather, then you can gain a substantia<

25、/p><p><b>　　中文翻譯 </b></p><p>　　什么是最大功率點跟蹤(MPPT),它是又如何工作的? </p><p>　　光伏發(fā)電作為可再生能源變得日益重要，它有許多有點，如不需燃料、沒有污染、需要很少的維護(hù)費用、沒有噪聲等等。光電模塊的轉(zhuǎn)換效率依然很低，所以控制光伏陣列的最大功率點跟蹤成為光伏系統(tǒng)的要點。 </p>

26、<p>　　光伏系統(tǒng)產(chǎn)生的能量取決于陣列的開路電壓。PV 的最大功率點（MPP）隨光照強(qiáng)度和和溫度變化。它的 V-I 和 V-P 特性曲線表示了一個特定的工作點，在這個點上可以提供最大功率。在最大功率點上，光伏系統(tǒng)工作具有最高效率。所以許多方法被用來確定最大功率跟蹤。</p><p>　　最大功率點跟蹤，經(jīng)常被稱為 MPPT，是一個使光電(PV)模塊工作在一種特定運作模式的電子系統(tǒng)，這種運作模式能夠

27、讓模塊產(chǎn)生它們所能夠產(chǎn)生的最大電力。 MPPT 不是一種移動模組本身來使它們更直接面對太陽的機(jī)械跟蹤系統(tǒng)。 MPPT是完全的電子系統(tǒng),它通過改變模組的電特性工作點，讓模塊能夠提供最大可用電力。從模塊得到的額外電力將以電池充電電流的形式得到利用。MPPT 可與機(jī)械跟蹤系統(tǒng)配合使用,但這兩個系統(tǒng)完全不同。</p><p>　　為了了解 MPPT 使如何工作的，我們先了解一下常規(guī)的(非 MPPT)充電控制器是如何工作的

28、。當(dāng)一個 常規(guī)控制器在為用完的蓄電池充電的時候，它只是簡單的將光伏模組與電池直接相連。這就促使模組工作在蓄電池的電壓上，而這個電壓通常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。光電模塊的功率/電壓/電流圖顯示了典型的傳統(tǒng)75W的光伏模塊在25°C電池溫度和1000w/m2日照強(qiáng)度的標(biāo)準(zhǔn)測試條件下的電流/電壓曲線。這個圖表也顯示了光電組件電壓變化時功率的變化. 如例子所示，傳統(tǒng)的控制器只是簡單的將光電模塊和電池相連，這就

29、促使模塊工作在 12V 電壓。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。 </p><p>　　與簡單地連接光電模塊與電池不同的是，在光電 Boost 充電控制器中使用的專利 MPPT 系統(tǒng)計算模塊能夠產(chǎn)生最大電能的工作電壓。這個例子中模塊產(chǎn)生最大功率時的電壓（VMP）是 17V。 MPPT 系統(tǒng)將使模塊工作在 17V 的電壓下來充分獲得 75W 的

30、電能，而不管目前電池的電壓。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。 如果整個系統(tǒng)布線全部是100%的效率,在目前這個例子中電池電流為 VMODULE ÷ VBATTERY x IMODULE 或17V ÷12V x 4.45A = 6.30A。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 1.85A 的充電電流或達(dá)到 42%的增量

31、。 但是,沒有什么是 100%的效率， 由于部分電力損失在線路、 保險絲、 電路斷路器和 Boost太陽能充電控制器上面，所以電流增量通常都會低一些。 </p><p>　　有用充電電流增量隨工作條件的變化而變化。如上所述,光電組件最大功率點電壓（VMP）與電池電壓的差異越大，充電電流增加的也就越大。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。 這是因為， 隨著光伏電

32、池單元的溫度降低最大功率點電壓和可用電能將增加，如光電組件溫度特性曲線所示， 模塊 25°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。 一個完全用完的蓄電池也將增加充電電流， 因為電池電壓更低同時通過 MPPT輸出到蓄電池的電能可以認(rèn)為時連續(xù)的。在適當(dāng)?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%。更低的溫度和更完全使用的蓄電池將使

33、充電電流增幅超過 40%。寒冷氣候下的客戶報道說充電電流甚至超過了 40%的增幅。這是意味著最需要的時候，充電電流增加的最大。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。在那些沒有可以利用的額外能量（滿充的蓄電池和高溫光電組件）的條件下，Boost 光電充電控制器將替代傳統(tǒng)的 PWM 型控制器。 </p><p>　　為什么要最大功率點跟蹤（MPPT）? </p><p&

34、gt;　　MPPT 附加在太陽能電池板上使它工作在最大功率點上。MPPT 是一個利用高頻開關(guān)和控制算法的 DC/DC 變換器。它要求將電路設(shè)計得高效率、重量輕、體積小、高可靠性。太陽能電池單元依賴環(huán)境條件比如溫度條件，光照強(qiáng)度，負(fù)載電壓。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。某些小時內(nèi)光電系統(tǒng)可能產(chǎn)生的功率低于額定負(fù)載功率。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

35、行特性將隨環(huán)境條件的改變而改變。這個問題可以通過使用較大的太陽能板來解決，但解決方案較昂貴?；诖耍谔柲茈姵匕搴碗姵刂g加設(shè)電池最大功率點跟蹤電路。 </p><p>　　利用 MPPT 功率跟蹤充電控制器增加光伏充電電能。 </p><p>　　充電控制器又出現(xiàn)了新的特點。它被稱為最大功率點跟蹤(MPPT)。它在一定條件下從你的光伏陣列攝取額外的電能。 本文為那些根本不懂電的人對這一

36、過程做了機(jī)械類比。MPPT 的功能類似于汽車的傳動裝置，當(dāng)傳動裝置運轉(zhuǎn)在錯誤的檔位，車輪得不到最大的動力。那是因為發(fā)動機(jī)運行速度低于或高于理想轉(zhuǎn)速范圍。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。 讓我們把光電組件和汽車發(fā)動機(jī)做下比較。它的電壓類似于引擎速度。理想的電壓是指在這一電壓點能夠輸出最大功率， 這就是所謂的最大功率點 (也被稱作峰值功率電壓,簡稱 VPP)。VPP 隨陽光強(qiáng)度和太陽能

37、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(fù)載（任何電器和燈泡等等）而變化。一個 12V 系統(tǒng)，則由約 11 至 14.5V 之間變化。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。如果光電組件的 VPP 只是僅僅略低于電池電壓,則電流也下降到近乎為零(如發(fā)動機(jī)轉(zhuǎn)得比車輪慢)。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</p>

38、<p>　　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(fù)荷特點。它為你提供有效的涌流，只有當(dāng) VPP 超過電池電壓約 1V 的時候。在炎熱的天氣，情況可能并非如此，除非電池欠充電。然而在寒冷天氣，VPP可以升到 18v。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)！ </p><p>　?。ǘ?

39、 Enengy or Solar Enegry</p><p>　　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 natur

40、al gas are energy sources available today because organisms in the past captured unlight energy and stored it in the complex organic molecules that made up their bodies, which were then compressed and concentrated. With

41、the development of society, alarge of energy sources have been used,such as coal, petroleum, natural gas,geothermal en</p><p>　　At present, most of the energy consumed by humans is produced from fossi fuels

42、. 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 di

43、sruption from mining and emissions of carbon dioxide and sulfur dioxide. These would become intolerable long before coal resources were exhausted. Only a small percentage of coal and lignite ha</p><p&g

44、t;　　Since first commercial 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 6

45、5 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 withi

46、n a few years. </p><p>　　Since the first "energy crisis" of 1973-1974, some concrete actions have even taken place. However, the several-fold increase in crude oil prices since 1973 has extacted a

47、toll. In the U.S. and other industrialized nations, the economy has been plagued by inflation, recession, unemployment, and obsolescence of industrial equipment. The economies of some petroleum-deficient developing count

48、ries have been devastated by energy prices. </p><p>　　Energy crisis was accompanied by worldwide shortages of some foods and minerals, followed in some cases by surpluses, such as the surplus wheat resulting

49、 from increased planting and a copper surplus resulting from the efforts of copper-producing nations to acpuire foreign currency by copper export. </p><p>　　As known to all,the availability and cost of energ

50、y has become dominant factors in society today. Obviously, solving the "energy crisis" makes good sense. Many schemes has been proposed for conserving present energy resources and for developing new ones. It is

51、 always possible to use less energy in any process. Therefore, energy engineer is created and developed. The first goal of energy engineer is to determine the methods by which energy utilization is reduced but the output

52、 remains the same, o</p><p>　　Conventional engineering techniques are used to evaluated the mechanisms of energy use. Economic considerations are of equal importance and life cycle cost and saving techniques

53、 are used to determine cost-effective measures. The evaluation focuses on those uses which are significant in the overall picture and attempts to determine those technical measures that can reduce usage and save money. &

54、lt;/p><p>　　Meanwhile, looking for ideal energy sources is also very important to solve energy crisis. The recipe for an ideal energy source calls for one that is unlimited in supply, widely available, and inex

55、pensive; it should not add to the earth's total heat burden or produce chemical air and water pollutants. Solar energy fulfills all of these criteria. Solar energy does not add excess heat to that which must be radia

56、ted from the earth. On a global basis, utilization of only a small fraction of solar e</p><p>　　Solar energy is unlimited in supply, but its exploitation and utilization are limited owing to the limitation o

57、f technology and conditions. Solar energy utilization needs an enormous amount of land, and there are economic and environmental problems related to the use of even a fraction of this amount of land for solar energy coll

58、ection. Certainly, many residents of Arizona would not be pleased at having so much of the state devoted to solar collectors, and some environmental groups would protest</p><p>　　Solar power cells for the di

59、rect conversion of sunlight to electricity have been developed and are widely used for energy in space vehicles. With present technology, however, they remain too expensive for large-scale generation of electricity. Ther

60、efore, most schemes for the utilization of solar power depend upon the collection of thermal energy, followed by conversion to electrical energy. The simplest such approach involves focusing sunlight on a steam-generatin

61、g bioler. Parabolic refkectors c</p><p><b>　　能源與太陽能</b></p><p>　　能源就是能夠用于工作和驅(qū)動機(jī)器的能量。所有的生物（包括人類）都是依靠陽光作為能量的來源。煤、石油和天然氣都是可以利用的能源，這些能源都是過去的生物體在太陽光能源的作用下生成復(fù)雜的存儲這些能源有機(jī)分子結(jié)構(gòu)經(jīng)過長時間的壓縮集中后生成的。大

62、量的能源已經(jīng)被使用，如煤炭、石油、天然氣、地?zé)豳Y源、核聚變能源、核裂變能源、太陽能和氫氣等。然而，在這種情況下，由于許多能夠產(chǎn)生能量的資源是不可再生的，大量的使用這些能源可能會引起能源危機(jī)。</p><p>　　目前，人類的能源消耗主要體現(xiàn)在燃料資源的消耗上?，F(xiàn)在的固體狀能源主要是煤炭，目前已知的加上潛藏的煤炭儲量最多可使用一到兩個世紀(jì)，而且煤炭的開采和使用會破壞環(huán)境并且產(chǎn)生大量的二氧化碳與二氧化硫。當(dāng)煤炭資源用

63、盡前這些影響將會越來越惡劣。煤炭在能源的利用方面的比例已經(jīng)越來越低，而石油和天然氣正在被大量的使用著。作為能源，石油比煤炭有更大的優(yōu)勢。其開采地比煤炭更為集中因此對環(huán)境的破壞要少，其燃燒產(chǎn)生的污染物要比煤炭少，而且石油可以很容易的通過管道進(jìn)行運輸。同時這些優(yōu)勢使石油成為理想的汽車燃料。</p><p>　　自從1859年第一個商業(yè)油田的建成以來，美國已經(jīng)生產(chǎn)了超過100萬桶石油，其中大部分是在最近幾年生產(chǎn)的。19

64、90年全世界約消耗了65萬桶石油。石油與天然氣資源在迅速的消耗著，阿拉斯加出產(chǎn)的石油只能暫時緩解石油的供應(yīng)危機(jī)。世界石油的生產(chǎn)將在幾年之內(nèi)達(dá)到最高值。</p><p>　　自從1973～1974年的第一次“能源危機(jī)”以來，已經(jīng)出現(xiàn)了一些具體的措施。然而，自1973年以來，原油的價格已經(jīng)提高了若干倍。美國和其他工業(yè)化國家一直受到通貨膨脹、經(jīng)濟(jì)衰退、大批的失業(yè)和工業(yè)設(shè)備的過時的困擾。一些石油不足的發(fā)展中國家由于能源價

65、格的關(guān)系其經(jīng)濟(jì)已經(jīng)遭到破壞。</p><p>　　在能源危機(jī)的同時，世界范圍內(nèi)還有一些食品和礦產(chǎn)資源的短缺，其次一些物品的生產(chǎn)則出現(xiàn)過剩，如小麥和銅的生產(chǎn)過剩，一些銅生產(chǎn)國將銅以銅幣的形式出口。</p><p>　　眾所周知，能源的供應(yīng)和成本已經(jīng)成為當(dāng)今社會的一個主要的話題。很顯然，解決“能源危機(jī)”是非常有意義的。目前已經(jīng)有許多節(jié)約能源和發(fā)展新能源的計劃被提出來。在任何領(lǐng)域節(jié)約能源都是可行

66、的。因而，能源工程師這個職業(yè)產(chǎn)生并迅速發(fā)展起來。能源工程師的第一個提議是想辦法減少能源的消耗同時保證產(chǎn)量不變甚至有所提高，第二個提議是尋找降低能源成本的方法。</p><p>　　傳統(tǒng)的工程技術(shù)被用來評估能源利用的技術(shù)。周期成本與用于節(jié)省資金的方法與經(jīng)濟(jì)利益同等重要。評價的重點是整個大局中的重要性和減少浪費和使用的資金的方法。</p><p>　　同時，尋找更為理想的能源是非常重要的。解決

67、能源危機(jī)的一種理想的能源的要求應(yīng)該是無限的供應(yīng)、能夠被廣泛的使用、價格低廉、而且其使用后不會添加地球的總熱量的負(fù)擔(dān)或者不會產(chǎn)生化學(xué)空氣和水污染物的排放。太陽能滿足這些標(biāo)準(zhǔn)，其產(chǎn)生的多余的熱量會從地球輻射出去。而且利用照射到地球的一小部分太陽能就能夠提供地球所需的能源。</p><p>　　太陽能的供應(yīng)是無限的，但是由于技術(shù)和條件的限制，其開發(fā)和利用是有限的。太陽能的利用需要大量的土地，還有經(jīng)濟(jì)和環(huán)境方面的要求，而

68、且這一部分土地上太陽能的收集也只能達(dá)到一小部分。當(dāng)然，亞利桑那州的許多居民渴不喜歡國家大力發(fā)展太陽能的收集，而且一些環(huán)保組織也因為太陽能的收集對響尾蛇的生活習(xí)性等產(chǎn)生的影響而抗議太陽能收集裝置的實行。</p><p>　　太陽能電池能夠?qū)⑻柲苤苯愚D(zhuǎn)化為電能，而且已經(jīng)廣泛應(yīng)用于空間飛行器能源的提供。然而，以目前的技術(shù)水平如果應(yīng)用于大規(guī)模發(fā)電其代價于昂貴。因此，目前大多數(shù)太陽能發(fā)電方式仍舊是首先將太陽能轉(zhuǎn)化為熱能，