电气工程及其自动化专业英语翻译中国电力出版社苏小林56页PPT
电气工程及其自动化专业英语第一章课文翻译
第一章第一篇sectiongTwo variables u(t) and i(t) are the most basic concepts in an electric circuit, they characterize the various relationships in an electric circuitu(t)和i(t)这两个变量是电路中最基本的两个变量，它们刻划了电路的各种关系。
the charge e on an electron is negative and equal in magnitude to 1.60210×10 19C, while a proton carries a positive charge of the same magnitude as the electron. The presence of equal numbers of protons and electrons leaves an atom neutrally charged. 我们从基础物理得知一切物质是由被称为原子的基本构造部分组成的，并且每个原子是由电子，质子和中子组成的。
我们还知道电子的电量是负的并且在数值上等于 1.602100×10-12C，而质子所带的正电量在数值上与电子相等。
质子和电子数量相同使得原子呈现电中性。
We consider the flow of electric charges. A unique feature offlow of negative charges, as Fig.l-1 illustrates. This convention was introduced by Benjamin Franklin (l706～l790), the American scientist and inventor. Although we now know that current in metallic conductors is due to negatively charged electrons, we will follow the universally accepted conventionthat current is the net flow of positive charges. Thus, Electriccurrent is the time rate of charge, measured in amperes (A).Mathematically, the relationship among current i , charge q , andtime t is 当我们把一根导线连接到某一电池上时(一种电动势源)，电荷被外力驱使移动；正电荷朝一个方向移动而负电荷朝相反的方向time in several ways that may be represented by different kindsof mathematical functions 我们通过方程（1－1）定义电流的方式表明电流不必是一个恒值函数，电荷可以不同的方式随时间而变化，这些不同的方式可用各种数学函数表达出来。
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 thanever 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), 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 Thomas Edison –the historic Pearl Street Station in New York City which began operation 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 suppliedat 110 V through an underground cable system.. Within a few years similar systems were in operation in most large cities throughout the world. Withthe development of motors by Frank Sprague in 1884, motor loads were addedto such systems. This was the beginning of what would develop into oneof the largest industries in the world. In spite of the initial widespreaduse of DC systems, they were almost completely superseded by AC systems. 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, 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 became a necessity.The development of the transformer and AC transmission by L. Gaulard and JD Gibbs 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 overa distance of 21 km. With the development of polyphase systems by Nikola Tesla, the AC system became even more attractive. By 1888, Tesla held several patents on AC motors, 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, 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）V oltage levels can be easily transformed in AC systems, thus providing the flexibility for use of different voltages forgeneration, 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 southern California. In the early periodof AC power transmission, frequency was not standardized. This poses a problem for interconnection. Eventually 60 Hz was adopted as standardin North America, although 50 Hz was used in many other countries. The increasing need for transmitting large amounts of power over longer distance created an incentive to use progressively high voltage levels.To avoid the proliferation of an unlimited number of voltages, theindustry 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 kV for the extra-high voltage (EHV) class. In China, the voltage levels in use are 10, 35, 110 for HV class, 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 the development of the AC/DC converting 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 asynchronouslink between systems where AC interconnection would be impracticalbecause of system stability consideration or because nominal frequenciesof the systems are different. The basic requirement to a power systemis to provide an uninterrupted energy supply to customers with acceptablevoltages and frequency. Because electricity can not be massively storedunder a simple and economic way, the production and consumption ofelectricity must be done simultaneously. A fault or misoperation in anystages of a power system may possibly result in interruption ofelectricity supply to the customers. Therefore, a normal continuousoperation of the power system to provide a reliable power supply to the customers is of paramount importance. Power system stability may bebroadly defined as the property of a power system that enables it to remainin a state of operating equilibrium under normal operating conditionsand to regain an acceptable state of equilibrium after being subjectedto a disturbance.. Instability in a power system may be manifested inmany different ways depending on the system configuration and operatingmode. Traditionally, the stability problem has been one of maintaining synchronous operation. Since power systems rely on synchronous machinesfor generation of electrical power, a necessary condition forsatisfactory system operation is that all synchronous machines remainin synchronism or, colloquially in step. This aspect of stability isinfluenced by the dynamics of generator rotor angles and power-angle relationships, 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。
电气工程及其自动化专业专业英语-词-选择和引申课件.ppt
A car needs a lot of power to go fast. 汽车高速行驶需要很大的动力。
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根据词的联立关系确定词义
Universal meter 万用表 Universal motor 交直流两用电动机（通用式） Universal valve 万向阀 Universal contact 万能接头 Universal constant 普适常量 Universal rules 普遍规律
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根据词的联立关系确定词义
Low damping Low limit Low life Low key Low brake Low order
弱阻尼 下限 下层社会生活 低音调键 低速制动 低位
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使用场合的提示
Operational order
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根据词类选择词义(2)
Round surface reflector is a key unit for the solar energy device. 弯曲面反射器是太阳能装置的关键元件。（形容词）
The tree measures about one meter round. 这棵树树围约一米。（副词）
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词义的引申(续)
概括化或抽象化引申 ➢ The plan for launching the man-made satellite still lies on the table. 发射人造卫星的计划仍被搁置。 ➢ Military strategy may bear some similarity to the chessboard(棋盘) but it is dangerous to carry the analogy too far 打仗同下棋可能有某些相似之处，但如果把这 两者之间的类比搞过了头则是危险的。
电气工程及其自动化专业英语翻译
One operating system might be better suited to some computing tasks than others.To provide clues to their strengths and weaknesses,operating systems are informally categorized and characterized using one or more of the following terms:(1) A single-user operating system expects to deal with oneset of input devices -those that can be controlled by one user at a time.Operating systems for handheld computers and many personal computers fit into the single-user category.(2)A multiuser operating system is derigned to deal with input,output,and processing requests from many users-all atthe same time.One of its most difficult responsibilities is to schedule all of the processing requests that must be performed by a centralized computer-often a mainframe.(3)A network operating system(also referred to as a “server operating system”) provides communications and routing services that allow compoters to share data,programs,and peripheral devices.Novell Netware,for example,is almost always referred to as a network operating system。
(完整版)电气工程及其自动化专业英语第一章课文翻译
第一章第一篇sectiongTwo variables u(t) and i(t) are the most basic concepts in an electric circuit, they characterize the various relationships in an electric circuitu(t)和i(t)这两个变量是电路中最基本的两个变量，它们刻划了电路的各种关系。
Charge and CurrentThe concept of electric charge is the underlying principle for explaining all electrical phenomena. Also, the most basic quantity in an electric circuit is the electric charge. Charge is an electrical property of the atomic particles of which matter consists, measured in coulombs (C).电荷和电流电荷的概念是用来解释所有电气现象的基本概念。
也即，电路中最基本的量是电荷。
电荷是构成物质的原子微粒的电气属性，它是以库仑为单位来度量的。
We know from elementary physics that all matter is made of fundamental building blocks known as atoms and that each atom consists of electrons, protons, and neutrons. We also know that the charge e on an electron is negative and equal in magnitude to 1.60210×10 19C, while a proton carries a positive charge of the same magnitude as the electron. The presence of equal numbers of protons and electrons leaves an atom neutrally charged.我们从基础物理得知一切物质是由被称为原子的基本构造部分组成的，并且每个原子是由电子，质子和中子组成的。
电气工程及其自动化专业英语翻译中国电力出版社苏小林ppt课件
第三节 欧姆定律
用来模拟材料阻流性能的电路元件是电阻 ，电阻是最简单的无源元件。
德国物理学家乔治西蒙欧姆（1787～ 1854），1826年根据实验提出电阻的电流— —电压关系，为此而享誉世界。这一关系被 称为欧姆定律。
欧姆定律表明电阻器两端的电压正比于流过 电阻器的电流。这个比例常值就是该电阻器以欧 姆为单位的电阻值。电阻器的电路符号如图1－8 所示。
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Exercises（12） 在下面进行的工作中我们要研究的简单电路元件 可以根据流过元件的电流与元件两端的电压的关系进行 分类。例如，如果元件两端的电压正比于流过元件的电 流，即u＝ki，我们就把元件称为电阻器。其他的类型的 简单电路元件的端电压正比于电流对时间的导数或正比 于电流关于时间的积分。还有一些元件的电压完全独立 于电流或电流完全独立于电压，这些是独立源。此外， 我们还要定义一些特殊类型的电源，这些电源的电压或 电流取决于电路中其他的电流或电压，这样的电源将被 称为非独立源或受控源。
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idq dt
从时间t0到时间t所移送的电荷可由方程（1－1）两 边积分求得。我们算得：
t
q idt t0
我们通过方程（1－1）定义电流的方式表明电流 不必是一个恒值函数，电荷可以不同的方式随时间 而变化，这些不同的方式可用各种数学函数表达出 来。
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电压，能量和功率 在导体中朝一个特定的方向移动电荷需要一些功 或者能量的传递，这个功是由外部的电动势来完成的。 图1－1所示的电池就是一个典型的例子。这种电动势 也被称为电压或电位差。电路中a、b两点间的电压等 于从a到b移动单位电荷所需的能量（或所需做的功） 。数学表达式为：
pdw dt
式中p是以瓦特为单位的功率，w是以焦耳为 单位的能量，t是以秒为单位的时间，从方程（ 1－1）、（1－3）和（1－5）可以推出
电气工程及其自动化专业英语 ppt课件
If possible (necessary)如果可能（必要）Where possible 在可能的情况下
Grammar Features
语法特点
(4) It句型和祈使句使用频繁 （准确、精炼）
It句型：it 充当形式主语，避免句子“头重脚轻”
祈使句: 无主语，精炼。
It is very important (possible, necessary, natural, inevitable) to… It takes very much time learning… It is clear (possible, necessary, natural, inevitable) that… It happened that … It must be admitted that…
Let A be equal to B.设A等于B。 Consider a high-pressure chamber. 假如有一个高气压气候室。
Grammar Features
语法特点
(5) 复杂长句使用频繁 （准确、精炼）
为了完整、准确地表达事物内在联系，使用大量从句
1) It has been mentioned above that the electrons in a metal are able to move freely through the metal, that their motion constitutes an electric current in the metal and that they play an important part in conduction of heat.
就像图1所示的那样，这个闭环系统中有一个反馈元件。
电气工程及其自动化专业专业英语-词-转换增译省译课件.ppt
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为符合汉语表达习惯而增译
These motors are expensive, but good. 这批马达很贵，但质量很好
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代词转译成汉语名词
The voltage induced in the core is small, because it is essentially a winding having but one turn. 铁芯的感应电压小，因为铁芯实质上是一个只有 一匝的绕组
This means the permittivity of oil is greater than that of air. 这就意味着油的介电系数大于空气的介电系数
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动词转译成汉语形容词
Light waves differ in frequency just as sound waves do. 同声波一样，光波也有不同的频率
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转译成汉语副词
The language allows a concise expression of arithmetic and logic processes. 这种语言能简要地表达算术和逻辑过程
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省译冠词
冠词：a, an, the
A transistor is a device controlling the flow of electricity in a circuit 晶体管是在电路中控制电流的器件