电气工程及其自动化专业英语翻译

1、电气工程及其自动化专业英语 翻译电气工程及其自动化专业英语 翻译Electric Power Systems.The modern society depends on the electricity supply more heavily than ever before. It can not be imagined what the world should be if the electricity supply were interrupted all over the world. Electric power systems (or electric energy systems

2、), providing electricity to the modern society, have become indispensable components of the industrial world.The first complete electric power system (comprising a generator, cable, fuse, meter, and loads) was built by ThomasEdison the historic Pearl Street Station in NewYork City which began operat

3、ion in September 1882. This was a DC system consisting of a steam-engine-driven DC generator supplying power to 59 customers within an area roughly 1.5 km in radius. The load, which consisted entirely of incandescent lamps, was supplied at 110 V through an underground cable system. Within a few year

4、s 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 widesp

5、read use of DCsystems, they were almost completely superseded by ACsystems. By 1886, the limitations of DC systems were becoming increasingly apparent. They could deliver power only a short distance from generators. To keep transmission power losses ( I 2 R ) and voltage drops to acceptable levels,

6、voltage levels had to be high for long-distance power transmission. Such high voltages were not acceptable for generation and consumption of power; therefore, a convenient means for voltage transformation becamea necessity.The development of the transformer and AC transmission by L. Gaulard and JD G

7、ibbs of Paris, France, led to AC electric power systems. In 1889, the first AC transmission line in North America was put into operation in Oregon between Willamette Falls and Portland. It was a single-phase line transmitting power at 4,000 V over a distance of 21 km. With the development of polypha

8、se systems by Nikola Tesla, the AC system became even more attractive. By 1888, Tesla held several patents on ACmotors, generators, transformers, and transmission systems. Westinghouse bought the patents to these early inventions, and they formed the basis of the present-day AC systems. In the 1890s

9、, there was considerable controversy over whether the electric utility industry should be standardized on DC or AC. By the turn of the century, the AC system had won out over the DC system for the following reasons:( 1) Voltage levels can be easily transformed in AC systems, thus providing the flexi

10、bility for use of different voltages for generation, transmission, and consumption.( 2) AC generators are much simpler than DC generators.( 3) AC motors are much simpler and cheaper than DC motors.The first three-phase line in North America went into operation in 1893 a 2,300 V, 12 km line in southe

11、rn California. In the early periodof AC power transmission, frequency was not standardized. This poses a problem for interconnection. Eventually 60 Hz was adopted as standard in North America, although 50 Hz was used in many other countries. The increasing need for transmitting large amounts of powe

12、r over longer distance created an incentive to use progressively high voltage levels. To avoid the proliferation of an unlimited number of voltages, the industry has standardized voltage levels. In USA, the standards are 115, 138, 161, and 230 kV for the high voltage (HV) class, and 345, 500 and 765

13、 kV for the extra-high voltage (EHV) class. In China, the voltagelevels in use are 10, 35, 110 for HVclass, and 220, 330 (only in Northwest China) and 500 kV for EHV class . The first 750 kVtransmission line will be built in the near future in Northwest China. With thedevelopment of the AC/DC conver

14、ting equipment, high voltage DC (HVDC) transmission systems have become more attractive and economical in special situations. The HVDC transmission can be used for transmissionof large blocks of power over long distance, and providing an asynchronous link between systems where AC interconnection wou

15、ld be impractical because of system stability consideration or because nominal frequencies of the systems are different. The basic requirement to a power system is to provide an uninterrupted energy supply to customers with acceptable voltages and frequency. Because electricity can not be massively

16、stored under a simple and economic way, the production and consumption of electricity must be done simultaneously. A fault or misoperation in any stages of a power system may possibly result in interruption of electricity supply to the customers. Therefore, a normal continuous operation of the power

17、 system to provide a reliable power supply to the customers is of paramount importance. Power system stability may be broadly defined as the property of a power system that enables it to remain in a state of operating equilibrium under normal operating conditions and to regain an acceptable state of

18、 equilibrium after being subjectedto a disturbance. Instability in a power system may be manifested inmany differentways depending on the system configuration and operatingmode. Traditionally, the stability problem has been one of maintainingsynchronous operation. Since power systems rely on synchro

19、nous machines for generation of electrical power, a necessary condition for satisfactory system operation is that all synchronous machines remain in synchronism or, colloquially "in step". This aspect of stability is influenced by the dynamics of generator rotor angles and power-angle rela

20、tionships, and then referred to " rotor angle stability "译文：电力系统现代社会比以往任何时候更多地依赖于电力供应。如果世界各地电力供应中断了 ,无法想象世界会变成什么样。电力系统（或电力能源系统），提供电力到现代社会， 已成为产业界不可缺少的组成部分。 历史上第一个完整的电力系统 （包括发电机，电缆，熔断器，计量，加载）由托马斯爱迪生所建纽约市珍珠街电站， 始于 1882 年 9 月运作。 这是一个直流系统组成蒸汽发动机驱动的直流发电机，供电范围面积约 1.5 公里，送给59 个客户。他们的负载，其中包括白炽灯， 通

21、过地下电缆系统提供110V 电压。 一个个类似的系统在世界各地大多数大城市运行了数年。随着弗兰克斯普拉格在1884 年对马达的发展， 电机负载被添加到这些系统，从此开始发展成为世界上最大的产业之一。最初的直流系统被广泛使用，尽管如此，他们几乎完全被交流系统所取代。到 1886 年，直流系 统的局限性也日益明显。他们从发电机提供功率只有很短的距离。为了保持发射功率损失（ I 2 R ）和电压下降到可接受的水平，长途输电电压必须高。如此高的电压发电和电力消耗是可以接受的，因此，电压转换有一个方便的手段成为了必要。 法国的 L. 巴黎戈拉尔和 JD 吉布斯发展了变压器和交流输电并引领了交流电力系统。

22、 1889 年，在北美波特兰和威拉梅特大瀑布之间的俄勒冈州第一次实施交流传输线。这是一个单相线路传输为 4,000 伏，超过 21 公 里距离的系统。随着交流的发展多相系统由尼古拉特斯拉，成为更具吸引力的。在 1888 年，尼古拉特斯拉取得多项交流专利，包括电动机，发电机，变压器和输电系统。西屋公司购买了这些早期的发明专利，并形成了现在交流系统的基础。 19 世纪 90 年代，有很大的争议在于直流或交流电力行业是否应该统一。到了世纪之交时，下面的原因使交流系统赢过了直流系统：（ 1）交流系统电压水平可以很容易地改变，从而提供了传输的灵活性，发电用不同的电压和消费。（ 2）交流发电机比直流发电机简单得多。（ 3）交流电机的马达比直流简单且便宜得多。首次三相交流电线1893 年投产于北美南加州 - 1 根 2300V ， 12 公里长的线路。在电力传输初期交流频率并不规范。 有许多不同频率在使用： 25 ， 50， 60 ， 125 ，和