電力系統(tǒng)的演化外文翻譯-其他專業(yè)-展示頁
2025-01-31 03:23本頁面
【正文】 ized from the beginning and interconnections continue to grow. Almost all the utilities in the United States and Canada are now part of one i nterconnected system of enormous plexity. The design of such a system and its secure operation are indeed challenging problems. STRUCTURE OF THE POWER SYSTEM Electric power system varies in size and structural ponents. However, they all have the same basic characteristics: ● Are prised of threephase ac systems operating essentially at constant voltage. Generation and transmission facilities use threephase equipment. Industrial loads are invariably threephase。中文 2188 字 EVOLUTION OF ELECTRIC POWER SYSTEMS The mercial use of electricity began in the late1870s when arc lamps were used for lighthouse illumination and street lighting. The first plete electric power system (prising a generator, cable, fuse, meter, and loads)was built by Thomas Edisonthe historic Pearl Street Station in New York City which began operation in September was a dc system consisting of a steamenginedriven dc generator supplying power to 59 customers within an area roughly in radios. The load, which consisted entirely of incandescent lamps, was supplied at 110 V through an underground cable system. Within a few years similar systems were in operation in most large cities throughout the world. With the development of motors by Frank Sprague in 1884, motor loads were added to such systems. This was the beginning of what would develop into one of the largest industries in the world. In spite of the initial widespread use of dc systems, they were almost pletely superseded by ac systems. By 1886, the limitations of dc systems were being increasingly apparent .They could deliver power only a short distance from the generators. To keep transmission power losers (RI2) and voltage drops to acceptable levels, voltage levels had to be high for longdistance power transmission. Such high voltages were not acceptable for generation and consumption of power。 therefore, a convenient means for voltage transformation became a necessity. The development of the transformation and ac transmission by L. Gaulard and . Gibbs of Paris, France, led to ac electric power systems. Gee Westinghouse secured rights to these developments in the United States. In 1886, William Stanley, an associate of Wes
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