外文翻譯---電源系統(tǒng)的歷史

1、<p><b>　　附 錄</b></p><p><b>　　附錄A 英文原文：</b></p><p>　　history of electric power system</p><p>　　In 1878, Thomas A. Edison began work on the electric ligh

2、t and formulated the concept of a centrally located power station with distributed lighting serving a surrounding area. He perfected his light by October 1879, and the opening of his historic Pearl Street Station in New

3、York city on September 4, 1882, marked the beginning of the electric utility industry. At Pearl Street, dc generators, then called dynamos, were driven by steam engines to supply an initial load of 30kW for 110-V incande

4、sce</p><p>　　The introduction of the practical dc motor by Sprague electric, as well as the growth of incandescent lighting, promoted the expansion of Edison’s dc systems. The development of three-wire 220-V

5、 dc systems allowed load to increase somewhat, but as transmission distances and loads continued to increase, voltage problems were encountered. These limitations of maximum distance and load were overcome in 1885 by Wil

6、liam Stanley’s development of a commercially practical transformer. Stanley installed </p><p>　　The growth of ac systems was further encouraged in 1888 when Nikola Tesla presented a paper at a meeting of the

7、 American Institute of Electrical Engineers describing two-phase induction and synchronous motors, which made evident the advantages of polyphase versus single-phase systems. The first three-phase line in Germany became

8、operational in 1891, transmitting power 179 km at 12 kV. The first three-phase line in the United States (in California) became operational in 1893, transmitting power 1</p><p>　　In the same year that Edison

9、’s steam-driven generators were inaugurated, a waterwheel-driven generator was installed in Appleton, Wisconsin. Since then, most electric energy has been generated in steam-powered and in water-powered (called hydro) tu

10、rbine plants. Today, steam turbines account for more than 85% of U.S. electric energy generation, whereas hydro turbine account for about 7%. Gas turbines are used in some cases to meet peak loads.</p><p>　　

11、Steam plants are fueled primarily by coal, gas, oil, and uranium. Of these, coal is the most widely used fuel in the United States due to its abundance in the country. Although many of these coal-fueled power plants were

12、 converted to oil during the early 1970s, that trend has been reversed back to coal since the 1973/74 oil embargo, which caused an oil shortage and created a national desire to reduce dependency on foreign oil. In 1957,

13、nuclear units with 90MW steam-turbine capacity, fueled by ur</p><p>　　Starting in the 1990s, the choice of fuel for new power plants in the United States has been natural gas. The gas-fired turbine is safe,

14、clean, more efficient than competing technologies, and uncontroversial. As of 2001, the tread toward natural gas has accelerated. It is estimated that 200 large gas-fired plants are being developed, accounting for 75-90%

15、 of planned U.S. Expansion. However, increasing natural gas prices may slow this trend. </p><p>　　Other types of electric power generation are also being used, including wind-turbine generators; geothermal p

16、ower plants, wherein energy in the form of steam or hot water is extracted from the earth’s upper crust; solar cell arrays; and tidal power plants. These sources of energy cannot be ignored, but they are not expected to

17、supply a large percentage of the world’s future energy needs. On the other hand, nuclear fusion energy just may. Substantial research efforts have shown nuclear fusion ene</p><p>　　The early ac systems opera

18、ted at various frequencies including 25, 50, 60, and 133 Hz. In 1891, it was proposed that 60 Hz be the standard frequency in the United States. In 1893, 25-Hz systems were introduced with the synchronous converter. Howe

19、ver, these systems were used primarily for railroad electrification (and many are now retired) because they had the disadvantage of causing incandescent lights to flicker. In California, the Los Angeles Department of Pow

20、er and Water operated at 50 Hz, bu</p><p>　　The rate of growth of electric energy in the United States was approximately 7% per year from 1902 to 1972. This corresponds to a doubling of electric energy consu

21、mption every 10 years over the 70-year period. In other words, every 10 years the industry installed a new electric system equal in energy-producing capacity to the total of what it had built since the industry began. Th

22、e annual growth rate slowed after the oil embargo of 1973/74. Kilowatt-hour consumption in the United States increase</p><p>　　Along with increases in load growth, there have been continuing in creases in th

23、e size of generating units. The principal incentive to build larger units has been economy of scale – that is, a reduction in installed cost per kilowatt of capacity for larger units. However, there have also been steady

24、 improvements in generation efficiency. For example, in 1934 the average heat rate for steam generation in the U.S. electric industry was 17,950 BTU/kWh, which corresponds to 19% efficiency. By 1991, </p><p>

25、;　　There have been continuing increases, too, in transmission voltages. From Edison’s 220-V three-wire dc grid to 4-kV single-phase and 2.3-kV three-phase transmission, ac transmission voltages in the United States have

26、risen progressively to 150, 230, 345, 500, and now 765 kV. And ultra-high voltages (UHV) above 1000 kV are now being studied. The incentives for increasing transmission voltages have been: (1) increases in transmission d

27、istance and transmission capacity, (2) smaller line-voltage dro</p><p><b>　　附錄B 英文翻譯：</b></p><p><b>　　電源系統(tǒng)的歷史</b></p><p>　　1878年，愛迪生開始研究電燈，提出由位于中央的電站向四周地區(qū)提供照

28、明的想法。1879年10月，他進(jìn)一步改進(jìn)了他的電燈的設(shè)計(jì)，1882年9月4，紐約Peral街電站的運(yùn)行標(biāo)志著電力工業(yè)的開始。在Pearl街，由蒸汽機(jī)驅(qū)動(dòng)直流發(fā)電機(jī)向1平方里范圍內(nèi)的59個(gè)用戶的110V的白熾燈供電，供電負(fù)荷最初為30kW。從1882年至1972年，電力工業(yè)成長速度驚人，電能價(jià)格持續(xù)下降，主要原因是由于科技上不斷取得的成就和工程界創(chuàng)造性的成果。</p><p>　　由Sprague電力引進(jìn)的實(shí)用的直

29、流電機(jī)及白熾燈的發(fā)展推動(dòng)了愛迪生的直流系統(tǒng)的發(fā)展。3線220V直流系統(tǒng)的發(fā)明在一定程度上提高了供電負(fù)荷，但是當(dāng)輸電距離和負(fù)荷繼續(xù)增加，電壓成為一大問題。1885年William Stanley發(fā)明的經(jīng)濟(jì)可行的變壓器解決了這一在輸電距離和負(fù)荷上的限制問題。Stanley在Massachusetts的Great Barrington建立了一個(gè)交流配電系統(tǒng)，為150盞燈供電。變壓器使得電能可以在更高電壓和更低電流傳輸，降低了線路電壓降，使交流

30、系統(tǒng)比直流系統(tǒng)跟具吸引力。美國第一條單相交流線路1889年在Oregon運(yùn)行，該線路21公里，電壓等級為4kV，連接Oregon和Portland。</p><p>　　1888年Nikola Tesla在美國電氣工程師協(xié)會(huì)的會(huì)議上，提交了一篇講解兩相感應(yīng)和同步電機(jī)的論文，使得多相系統(tǒng)相對單相系統(tǒng)的優(yōu)勢更加明顯了，這更加推進(jìn)了交流系統(tǒng)的發(fā)展。1891年，第一條三相線路在德國運(yùn)行，傳輸距離179km,電壓等級12k

31、v。在1893年美國（加利福尼亞）的第一條三相線路開始運(yùn)行，傳輸距離12km，電壓等級2.3kv。Tesla所設(shè)想的三相感應(yīng)電動(dòng)機(jī)逐漸成為工業(yè)的主力。</p><p>　　蒸汽電廠的主要燃料是煤，天然氣，石油和鈾。其中，由于儲(chǔ)量豐富，煤是在美國使用最廣泛的燃料。雖然，在20世紀(jì)70年代早期很多以煤為燃料的電廠都轉(zhuǎn)化為以石油為燃料，然而由于1973年至1974年石油禁運(yùn)而導(dǎo)致的石油短缺，這一趨勢又被反轉(zhuǎn)以燃煤為主，

32、以減少對外國石油的依賴。1957年，相當(dāng)于90MW汽輪機(jī)裝機(jī)容量，以鈾為燃料的核電機(jī)組投建，如今，具有1312MW汽輪機(jī)裝機(jī)容量的核電機(jī)組在使用中。但是，由于建設(shè)費(fèi)用的增加，申請?jiān)S可的拖延和公眾的輿論阻礙了美國核電容量的增長。</p><p>　　自從20世紀(jì)90年代以來，美國新建電廠的燃料一直是天然氣。燃?xì)廨啓C(jī)安全，干凈，一致認(rèn)為比其他技術(shù)更有效率。截至2001年，天然氣的發(fā)展趨勢一直在加快。據(jù)估計(jì)，200個(gè)大

33、型燃?xì)怆姀S正在發(fā)展中，占據(jù)了美國電源規(guī)劃的75%－90%。然而，天然氣價(jià)格的提高可能會(huì)減慢燃?xì)怆姀S的發(fā)展。</p><p>　　其他類型的電力發(fā)電也在使用中，包括風(fēng)力渦輪發(fā)電機(jī)；從地殼獲得蒸汽或熱水形式能源的地?zé)岚l(fā)電廠，太陽電池陣列和潮汐發(fā)電廠。這些能源不容忽視，但預(yù)計(jì)它們不能滿足世界未來的大部分能源需求。相反，核聚變能源卻能夠滿足這一需求。大量的研究已經(jīng)表明，因核聚變能源生產(chǎn)安全，無污染并且節(jié)約（經(jīng)濟(jì)）電力能源

34、，其將是21世紀(jì)后期及以后一項(xiàng)大有可為的技術(shù)。核聚變反應(yīng)消耗的氚，海水是其幾乎取之不盡的補(bǔ)給。</p><p>　　最早的交流系統(tǒng)以25Hz, 50Hz, 60Hz和133Hz各種頻率運(yùn)行。1891年60Hz成為美國的標(biāo)準(zhǔn)頻率。1893年，通過采用同步換流器，開始使用25Hz系統(tǒng)。但是，這些系統(tǒng)主要用于鐵路電氣化(很多現(xiàn)在已經(jīng)退役)，因?yàn)樗鼈冇性斐砂谉霟糸W爍的缺點(diǎn)。加利福尼亞的水利電力部采用50Hz，但是，當(dāng)19

35、37年Hoover大壩開始運(yùn)作，頻率就轉(zhuǎn)換為60Hz。1949年南加利福尼亞的Edison公司也將頻率從50Hz轉(zhuǎn)變?yōu)?0Hz。今天，60Hz(在美國，加拿大，日本和巴西使用)和50Hz(在歐洲，前蘇聯(lián)，除巴西以外的南美洲，印度以及日本使用)是世界上發(fā)電，輸電和配電的兩個(gè)標(biāo)準(zhǔn)頻率。60Hz系統(tǒng)的優(yōu)點(diǎn)在于系統(tǒng)中的發(fā)電機(jī)，電動(dòng)機(jī)和變壓器通常比同等級50Hz系統(tǒng)的設(shè)備小。50Hz系統(tǒng)的優(yōu)點(diǎn)是傳輸線和變壓器的電抗在50Hz時(shí)較60Hz時(shí)小。&l

36、t;/p><p>　　從1902年到1972年美國電力能源以每年大約7％的速度增長。這相當(dāng)于在70年中每10年電能消耗就增加了一倍。換而言之，每10年電力工業(yè)新增的容量等于初始時(shí)所建容量的總和。1973/1974的石油禁運(yùn)之后，每年的增長率就比較緩慢了。1972到1980年美國的千瓦時(shí)消耗每年增長3.4％，而1980至2000年每年增長2.1％。</p><p>　　隨著負(fù)荷的增長，發(fā)電機(jī)組的

37、規(guī)模也在不斷的增加。投建較大機(jī)組的主要目的就是規(guī)模效應(yīng)，即減少了每千瓦容量的安裝成本。不過，發(fā)電效率也在穩(wěn)步的提高。由于機(jī)組規(guī)模和蒸汽溫度、壓力的改進(jìn)，還有蒸汽再加熱的使用，使得熱效率得到提高，節(jié)約了燃料費(fèi)用和總的運(yùn)行費(fèi)用。</p><p>　　傳輸電壓也在不斷地提高。從愛迪生的220V三相直流電網(wǎng)到單相4kV和三相2.3kV輸電，美國的交流輸電電壓已經(jīng)逐步上升到150，230，345，500和現(xiàn)在的765kV。