外文翻譯--太陽能發(fā)電的基礎(chǔ)

1、the basics of solar power for producing electricityusing solar power to produce electricity is not the same as using solar to produce heat. solar thermal principles are applied to produce hot fluids or air. photovoltaic principles are used to produce electricity. a solar panel is made of the natural

2、 element, silicon, which becomes charged electrically when subjected to sun light.solar panels are directed at solar south in the northern hemisphere and solar north in the southern hemisphere (these are slightly different than magnetic compass north-south directions) at an angle dictated by the geo

3、graphic location and latitude of where they are to be installed. typically, the angle of the solar array is set within a range of between site-latitude-plus 15 degrees and site-latitude-minus 15 degrees, depending on whether a slight winter or summer bias is desirable in the system. many solar array

4、s are placed at an angle equal to the site latitude with no bias for seasonal periods.the intensity of the suns radiation changes with the hour of the day, time of the year and weather conditions. to be able to make calculations in planning a system, the total amount of solar radiation energy is exp

5、ressed in hours of full sunlight perm, or peak sun hours. this term, peak sun hours, represents the average amount of sun available per day throughout the year.it is presumed that at peak sun, 1000 w/m of power reaches the surface of the earth. one hour of full sun provides 1000 wh perm = 1 kwh/m -

6、representing the solar energy received in one hour on a cloudless summer day on a one-square meter surface directed towards the sun. to put this in some other perspective, the united states department of energy indicates the amount of solar energy that hits the surface of the earth every +/- hour is

7、 greater than the total amount of energy that the entire human population requires in a year. another perspective is that roughly 100 square miles of solar panels placed in the southwestern u.s. could power the country.the daily average of peak sun hours, based on either full year statistics, or ave

8、rage worst month of the year statistics, for example, is used for calculation purposes in the design of the system. to see the average peak sun hours for your area in the united states, u.s.-solar insolation choose the area closest to your location for a good indication of your average peak sun hour

9、s.for a view of global solar isolation values (peak sun-hours) use this link: global peak sun-hour maps , then, you can use back or previous on your browser to return right here if you want to.so it can be concluded that the power of a system varies, depending on the intended geographical location.

10、folks in the northeastern u.s. will need more solar panels in their system to produce the same overall power as those living in arizona. we can advise you on this if you have any doubts about your area.the four primary components for producing electricity using solar power, which provides common 120

11、 volt ac power for daily use are: solar panels, charge controller, battery and inverter. solar panels charge the battery, and the charge regulator insures proper charging of the battery. the battery provides dc voltage to the inverter, and the inverter converts the dc voltage to normal ac voltage. i

12、f 240 volts ac is needed, then either a transformer is added or two identical inverters are series-stacked to produce the 240 volts.the output of a solar panel is usually stated in watts, and the wattage is determined by multiplying the rated voltage by the rated amperage. the formula for wattage is

13、 volts times amps equals watts. so for example, a 12 volt 60 watt solar panel measuring about 20 44 inches has a rated voltage of 17.1 and a rated 3.5 amperage.v a = w 17.1 volts times 3.5 amps equals 60 wattsif an average of 6 hours of peak sun per day is available in an area, then the above solar

14、panel can produce an average 360 watt hours of power per day; 60w times 6 hrs= 360 watt-hours. since the intensity of sunlight contacting the solar panel varies throughout the day, we use the term peak sun hours as a method to smooth out the variations into a daily average. early morning and late-in

15、-the-day sunlight produces less power than the mid-day sun. naturally, cloudy days will produce less power than bright sunny days as well. when planning a system your geographical area is rated in average peak sun hours per day based on yearly sun data. average peak sun hours for various geographica

16、l areas is listed in the above section.solar panels can be wired in series or in parallel to increase voltage or amperage respectively, and they can be wired both in series and in parallel to increase both volts and amps. series wiring refers to connecting the positive terminal of one panel to the n

17、egative terminal of another. the resulting outer positive and negative terminals will produce voltage the sum of the two panels, but the amperage stays the same as one panel. so two 12 volt/3.5 amp panels wired in series produces 24 volts at 3.5 amps. four of these wired in series would produce 48 v

18、olts at 3.5 amps. parallel wiring refers to connecting positive terminals to positive terminals and negative to negative. the result is that voltage stays the same, but amperage becomes the sum of the number of panels. so two 12 volt/3.5 amp panels wired in parallel would produce 12 volts at 7 amps.

19、 four panels would produce 12 volts at 14 amps.a charge controller monitors the batterys state-of-charge to insure that when the battery needs charge-current it gets it, and also insures the battery isnt over-charged. connecting a solar panel to a battery without a regulator seriously risks damaging

20、 the battery and potentially causing a safety concern.charge controllers (or often called charge regulator) are rated based on the amount of amperage they can process from a solar array. if a controller is rated at 20 amps it means that you can connect up to 20 amps of solar panel output current to

21、this one controller. the most advanced charge controllers utilize a charging principal referred to as pulse-width-modulation (pwm) - which insures the most efficient battery charging and extends the life of the battery. even more advanced controllers also include maximum power point tracking (mppt)

22、which maximizes the amount of current going into the battery from the solar array by lowering the panels output voltage, which increases the charging amps to the battery - because if a panel can produce 60 watts with 17.2 volts and 3.5 amps, then if the voltage is lowered to say 14 volts then the am

23、perage increases to 4.28 (14v 4.28 amps = 60 watts) resulting in a 19% increase in charging amps for this example.many charge controllers also offer low voltage disconnect (lvd) and battery temperature compensation (btc) as an optional feature. the lvd feature permits connecting loads to the lvd ter

24、minals which are then voltage sensitive. if the battery voltage drops too far the loads are disconnected - preventing potential damage to both the battery and the loads. btc adjusts the charge rate based on the temperature of the battery since batteries are sensitive to temperature variations above

25、and below about 75f degrees.the deep cycle batteries used are designed to be discharged and then re-charged hundreds or thousands of times. these batteries are rated in amp hours (ah) - usually at 20 hours and 100 hours. simply stated, amp hours refers to the amount of current - in amps - which can

26、be supplied by the battery over the period of hours. for example, a 350ah battery could supply 17.5 continuous amps over 20 hours or 35 continuous amps for 10 hours. to quickly express the total watts potentially available in a 6 volt 360ah battery; 360ah times the nominal 6 volts equals 2160 watts

27、or 2.16kwh (kilowatt-hours). like solar panels, batteries are wired in series and/or parallel to increase voltage to the desired level and increase amp hours.the battery should have sufficient amp hour capacity to supply needed power during the longest expected period no sun or extremely cloudy cond

28、itions. a lead-acid battery should be sized at least 20% larger than this amount. if there is a source of back-up power, such as a standby generator along with a battery charger, the battery bank does not have to be sized for worst case weather conditions.the size of the battery bank required will d

29、epend on the storage capacity required, the maximum discharge rate, the maximum charge rate, and the minimum temperature at which the batteries will be used. during planning, all of these factors are looked at, and the one requiring the largest capacity will dictate the battery size.one of the bigge

30、st mistakes made by those just starting out does not understand the relationship between amps and amp-hour requirements of 120 volt ac items versus the effects on their dc low voltage batteries. for example, say you have a 24 volt nominal system and an inverter powering a load of 3 amps, 120vac, whi

31、ch has a duty cycle of 4 hours per day. you would have a 12 amp hour load (3a 4 hrs=12 ah). however, in order to determine the true drain on your batteries you have to divide your nominal battery voltage (24v) into the voltage of the load (120v), which is 5, and then multiply this times your 120vac

32、amp hours (5 12 ah). so in this case the calculation would be 60 amp hours drained from your batteries - not the 12 ah. another simple way is to take the total watt-hours of your 120vac device and divide by nominal system voltage. usingthe above example; 3 amps 120 volts 4 hours = 1440 watt-hours di

33、vided by 24 dc volts = 60 amp hours.lead-acid batteries are the most common in pv systems because their initial cost is lower and because they are readily available nearly everywhere in the world. there are many different sizes and designs of lead-acid batteries, but the most important designation i

34、s that they are deep cycle batteries. lead-acid batteries are available in both wet-cell (requires maintenance) and sealed no-maintenance versions. agm and gel-cell deep-cycle batteries are also popular because they are maintenance free and they last a lot longer.太陽能發(fā)電的基礎(chǔ)太陽能發(fā)電板由天然成分的硅制成，受太陽光控制的電池板。太

35、陽能電池板是針對南方太陽北半球與的北方太陽南半球（這是稍有不同，羅盤的南北方向）的角度由地理位置和緯度位置來安裝的。通常，太陽能電池列陣的角度被設(shè)置在站點緯度加15度及實地緯度減15度，取決于冬季或夏季稍有的偏差。許多太陽能電池陣列處于一個沒有偏見的季節(jié)性周期的角度相等的站點。電荷被控制在光伏電池板內(nèi)，對外輸出一個低壓（直流電）通常是6-24v，最常見的輸出是12v，有效輸出高達17v。12v只是一個名義上的參考電壓，但是工作電壓是17v或者更高的電壓。就像您的汽車交流發(fā)電機充電為12v，可以超過12v。所以是有差別的參考電壓和實際操作電壓。太陽的輻射強度變化是以每天的天氣變化和時間的改變來變

36、化的。在計劃系統(tǒng)內(nèi)計算太陽總的輻射量，是以太陽光充足時每平方米的輻射量計算的。這個界限代表一年四季的平均輻射量。據(jù)推測，在“太陽峰值”時，熱量以1000w/m，到達地球的表面。熱量以每平方米1000千瓦時=1/米收到的太陽能代表一個小時晴朗夏日一平米太陽輻射到地表面。一方面，美國能源部表示，每小時太陽到達地球的輻射量大于整個人類一年的能量總額。另一方面，美國西南部地區(qū)能放置大約100平方英里的太陽能板。每日平均高峰太陽小時，或是基于全年統(tǒng)計最壞的一年或是平均每月統(tǒng)計數(shù)字，例如，用于計算系統(tǒng)的設(shè)計。要看到平均高峰小時的平均面積在美國，美國太陽日光浴選擇區(qū)域最接近你的位置為您的平均高峰太陽小時的一

37、個好征兆。因此可以斷定，系統(tǒng)的力量變化，取決于預(yù)定的地理位置。在美國東北部需要更多的太陽能電池板。如果你在這方面有任何懷疑的話，我們可以告訴你。四個主要部件使用太陽能發(fā)電，其中規(guī)定普通日用120伏特交流電源：太陽能電池板、充電控制器、蓄電池和逆變電源。太陽能電池板負(fù)責(zé)保險監(jiān)管的機構(gòu)，負(fù)責(zé)對電池的安全充電。電池提供直流電壓給逆變器，逆變器的直流電壓轉(zhuǎn)換為正常的交流電壓。如果需要240伏交流，然后加上一個變壓器或兩個相同的變頻器產(chǎn)生240伏特。太陽能發(fā)電板的輸出通常是瓦特，瓦數(shù)是由額定電壓乘額定電流得到。公式為瓦數(shù)是伏特乘安培等于瓦特。例如12伏特60瓦特太陽能電池板面積約為2044厘米，有17.

38、1v的額定電壓和3.5a的額定電流。va =w17.1伏特乘3.5安培均等60瓦特如果平均每天有6個小時高峰太陽是在可利用的區(qū)域，那么上述太陽能發(fā)電板可能平均每天產(chǎn)生360瓦特小時的電力，60w計時6小時的424倍=360個瓦特小時。由于接觸陽光的太陽能發(fā)電板，每天強度不一樣，我們用“太陽峰時間”考慮平均時間。凌晨和午后的陽光輻射量比午間太陽輻射量小。自然地，多云天的太陽輻射量也比明亮的晴天的太陽輻射量小。當(dāng)您的規(guī)劃系統(tǒng)區(qū)域內(nèi)的太陽輻射量明確后，平均高峰太陽小時也就列出了。太陽能板可以串聯(lián)或并聯(lián)以增加電壓電流。布線終端連接從一個小組到另一端的負(fù)極。由此正負(fù)電壓的終端將產(chǎn)生兩個的總和，但作為一個小組的電流不變。并行連接電線指正面和負(fù)面終端負(fù)轉(zhuǎn)正。結(jié)果是電壓不變，但電流得到一個總和。充電控制器