电气工程及其自动化专业英语
专业英语电路基础characterize描绘…的特征，塑造人物，具有….的特征property 性质，财产equal in magnitude to 在数量（数量级）上等同于convert 转换converter 转换器time rate 时间变化率mathematically 从数学上来讲differen tiate v 区分，区别in honor of 为纪念某人name in honor of为纪念某人而以他命名electromotive force （e m f ）电动势voltaic battery 伏打电池，化学电池an element 一个电器元件interpret 口译，解释，说明the potential at point a with respect to point b is点a关于点b的电势Potential difference/voltage 电势差/电压expend 花费，消耗instantaneous 瞬时的，促发的passive sign convention 关联参考方向the law of conservation of energy 能量守恒定律reference polarity 参考极性electron 电子electronic 电子的electric 电的，电动的time-varying 时变的constant-valued 常量的metal lic 金属的be due to 是因为，由于，归功于building block 模块Coulomb库伦，Ampere安培，joule焦耳，Volt伏特，Watt瓦特，work 功变量u（t），i(t)是电路中最基本的概念。
他们描述了电路中的各种关系。
电荷量的概念是解释电现象的基本原理，电荷量也是电路中最基本的量。
电荷也是构成物质的原子的电器属性，量纲是库伦。
我们从初等物理可以得知所有物质是由基本组成部分原子组成，而原子又包括电子（electron），质子（proton）和中子（neutron）我们都知道电荷e是带负电的电子，在数量上等于1.60210*1019 C, 而质子携带同等电荷量的正电荷，相同数量的质子，电子使原子呈现电中性（neutrally charged）。
我们细想一下电荷的流动，电荷或电流的一个特征就是它是可移动的，就是说从一个地方以能量转换的形式转移到另外一个地方。
当一根导线与电池相连，电荷被迫移动，正负电荷朝相反方向移动，这种移动形成电流，通常把正电荷移动的方向当成电流移动的方向，也就是负电荷移动的反方向。
这个规定是由美国科学家本杰明-富兰克林提出的。
尽管我们现在知道金属导体中的电流是由负电荷运动引起的，我们还是遵从“电流是正电荷的正向移动”这个普遍接受的规定。
所以，电流时电荷的时间变化率。
数学上来讲，电流，电量，时间的关系是i=d q/d t ，t0到t时间内转移的电荷量可以通过等式两端积分得到。
我们定义电流的方式表明电流是一个恒量函数，电荷随时间以各种形式的变化可用不同的数学函数来表现。
要让电子在导体中按特定方向移动需要做功或有能量转移。
这功被当成是（electromotive force）外部电动势，这个电动势也被称作电压降或者电势差，电路中a，b两点间的电压就是把单位电荷从a移到b所需要的能量，从数学的角度讲，U=d w/d q，，式中w表示功，单位是焦，q表示电荷，单位是库伦，u表示电压，单位是伏，是为纪念第一个制造出化学电池的意大利物理学家亚历山大-安东尼奥-伏特而以他命名。
所以，电压（电势）就是让单位电荷通过一个元件所需的能量，量纲是伏特。
图展示了连接于a，b两点间元件两端的电压，加号和减号用来表示参考方向或电压极性。
电压可以用两种方式解释：1.a点电势高于b点电势2.点a关于点b的电压。
它遵循的逻辑关系一般这样表示U a b=-U b a。
尽管电压，电流是电路中两个基本的变量，单靠它们是不够的。
出于实用目的，我们要知道功率和能量。
要把功率和能量和电压，电流联系起来，我们回想一下物理可知，功率是消耗或吸收能量的时率，量纲是瓦特。
我们把这种关系记作p=d w/d t，式中p是功率，单位是瓦，w是能量，单位是焦。
从上面几个式子可得p=u*i，因为u和i通常是时间函数，而功率是时变的量，被称为瞬时功率。
这吸收或放出的功率是元件两端电压和通过它的电流的乘积。
如果功率有一个加号，那么被输送功率或元件吸收功率。
相反，如果功率有一个减号，则元件提供（释放）能量，但是我们怎么知道什么时候功率是正或负呢？电流方向和电压极性在决定功率符号起决定作用。
所以注意电压和电流之间的关系是非常重要的。
电压极性和电流方向必须如图示一致才能保证功率符号是正的，这就是我们熟知的关联参考方向（passive sign convention）从关联参考方向得知，电流从电压的正极流入，在这种情况下，p大于0，表示元件吸收功率，但是如果p小于0，元件释放或提供能量。
实际上，所有电路都遵循（the law of conservation of energy ）能量守恒定律，因此，电路中功率的代数和在任何时刻都等于0。
这再次验证了提供给电路的总功率和吸收的总功率相等这个事实。
电路元件Active/passive element 有源/无源元件Inductor 电感器Ideal independent source 理想独立源Dependent/controlled source 受控源Constant voltage source 恒定电压源Diamond-shaped 菱形的Transistor 晶体管Amplifier 放大器Integrated circuit 集成电路By the same token 同理，同样，另外，还有一个电路就是一些电气元件的连接。
电路中有两种类型的元件：无源元件和有源元件。
有源元件能够产生能量而无源元件则不能。
无源元件的例子有：电阻，电容，电感。
最重要的有源元件就是向电路中所有与之相连的元件提供电能的电压和电流源。
一个理想的独立源是一个能够提供独立于其他变量的特定电压或电流。
一个独立电压源是一个二端元件，就像电池或发电机那样两个段子间维持特定电压值，这个电压和通过元件的电流是独立的。
电压源的符号是两个端子间有一个U伏的电压，如图所示。
极性如图，表明a端电压比b端高U伏，所以，如果U大于0，a端电势比b端电势高（terminal a is at a higher potential than terminal b ），反之亦可解释。
当然，如果U小于0，电压U可能是时变的，也有可能是恒定的，所以我们尚且标记为电压U。
另一个经常用作恒定电压源的符号，就好像是电池两端有U伏电压，如图所示。
恒流源情况下可以用左图两种方式表示，而且可以互换。
由于极性可以通过电池符号长线短线的位置来确定，我们可以观察到这时图示的极性符号就是多余的。
一个独立电流源就能有特定值电流流过的二端元件，这个电流与元件两端的电压是独立的。
独立电流源的符号如图所示，其中是一个定值，电流方向通过箭头方向表明。
独立源注定是向外部电路输出功率而不是吸收功率。
所以，如果Ｕ为独立源两端电压，电流Ｉ的方向是正端流出，考虑到ｐ＝ｕ×ｉ那么这个元件就是向外电路输出能量，否则就是在吸收能量。
图ａ中的电源向外电路输出２５ｗ功率，图ｂ中电源吸收２５ｗ功率，就像电池在充电一样。
（图b中电池就向充电一样，吸收24w功率）。
理想受控源是一个数值能被另外的电压或电流控制的有源元件。
受控源被设计成用菱形符号表示，如图。
因为受控源的控制是通过电路中其它的元件电压或电流来实现的，而且受控制的是电压或电流，所以它们有以下四种可能的类型。
电压控制电压源（v c v s）电流控制电压源（c c v s）电压控制电流源（v c c s）电流控制电压源（c c v s）独立源在模拟像晶体管，运算放大器，集成电路这样的元件时非常有用。
需要注意的是理想电压源（独立或受控）会产生任意大小的电流以确保两端电压，而理想电流源会产生必要的电压确保电流。
所以一个理想的独立源理论上会提供无穷大的能量。
还需注意的是独立远不仅给电路提供能量，还可以从电路中吸收能量。
对于电压源，我们知道它提供或吸收电压而不是电流，同理，我们知道电流源提供电流而不是两端的电压。
翻译所有处于某种工作状态的全部简单电路元件可以根据其通过电流和两端电压的关系来分类，例如，元件端电压正比于其通过的电流，或者u=k*I,我们把这种元件叫做电阻。
另外一种类型的电路元件端电压和时间的导数或者电流对于时间的积分成比例。
还有的电路元件电压与电流没有特定关系，也就是独立源，另外，我们还需定义被电路中其他支路上的电压或电流决定的特殊能量源，这种能量源被称为非独立源或受控源。
欧姆定律Incandescent 白炽（热）的，炽热的Incandescent lamp 白炽灯Voltage-current characteristic 伏安特性Si e mens 西门子Conductance 电导Short circuit 短路open circuit 开路具有阻碍电流的现象的这类物质就叫做电阻，电阻是最简单的无源元件。
乔治-西门-欧姆，德国物理学家，被认为在1826通过实验明确了电阻电压与电流的关系。
这种关系就是欧姆定律。
欧姆定律声明电阻两端电压正比于通过它的电流。
这个比例的数值就是电阻的电阻值，单位是欧姆（ohm）。
电路符号如图。
表示电阻的符号是大写的希腊字母Ω。
因为r是常数，图像是一条直线。
出于这种原因，电阻常称为线性电阻。
U对i的图像是一条经过原点斜率为r的直线。
因为无论电流是多少，电压对电流的比值是常数，图像只可能是一条直线。
不同电流时不维持恒定的电阻称为非线性电阻，这种电阻，阻值是电流的函数。
非线性电阻最简单的一个例子就是白炽灯。
图示是一种典型伏安特性曲线，可以看出，图像不再是一条直线。
因为r不为定值，使得有非线性电阻的电路更难分析了。
事实上，所有实际电阻都是非线性的，因为所有导体的电气特性受环境因素如温度的影响。
许多材料，在某一段工作区内非常接近线性电阻，我们可以关注这一类元件并且把它们当成线性电阻。
因为电阻值的范围是从0到无穷。
考虑这两种极端情况是非常重要的。
电阻为零称之为短路，图示电压为零，但是电流可以为任意值。
实验中，短路就是一根被认为是理想导体的导线。
短路就是电气元件的电阻接近0.相同的，电阻无穷大被称为是开路，开路表明电流是零，但是电压可以为任意值。
所以，开路就是电阻值接近无穷大。
在电路分析中另外一种很重要的量是电导。
电导是元件导电能力好坏的量度。
电导的单位是西门子。
电气工程及其自动化专业英语 Chapter 1 Fundamentals of Electric Circuits
Section1 Current and Voltage
flow as the movement of positive charges, that is, opposite to the flow 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 convention that current is the net flow of positive charges. Thus, Electric current is the time rate of charge, measured in amperes (A). Mathematically, the relationship among current i, charge q, and time t is
Section1 Current and Voltage
i
The charge transferred between time t0 and t is obtained by integrating both sides of Eq. (1-1). We obtain t
dq dt
(1-1)
q idt
电气工程及其自动化专业英语介绍
电气工程及其自动化专业英语介绍Introduction:Electrical Engineering and its Automation is a field of study that combines electrical engineering principles with automation techniques. This discipline focuses on the design, development, and implementation of electrical systems and their control using various automation technologies. In this article, we will delve into the various aspects of Electrical Engineering and its Automation, including its scope, key concepts, job opportunities, and future prospects.Body:1. Scope of Electrical Engineering and its Automation:1.1 Importance of Electrical Engineering:- Electrical engineering plays a vital role in various industries, including power generation, telecommunications, transportation, and manufacturing.- It involves the design and maintenance of electrical systems, such as power distribution networks, control systems, and electronic devices.1.2 Automation in Electrical Engineering:- Automation techniques are applied to enhance the efficiency, reliability, and safety of electrical systems.- Automation technologies, such as PLC (Programmable Logic Controller) and SCADA (Supervisory Control and Data Acquisition), are used for process control, monitoring, and data acquisition.1.3 Integration of Electrical Engineering and Automation:- The integration of electrical engineering principles with automation technologies enables the development of advanced control systems and intelligent machines.- It facilitates the automation of various industrial processes, leading to increased productivity and reduced human intervention.2. Key Concepts in Electrical Engineering and its Automation:2.1 Electrical Circuit Analysis:- This involves the study of electrical circuits and their behavior using mathematical models and techniques.- Concepts such as Ohm's law, Kirchhoff's laws, and circuit theorems are used to analyze and solve electrical circuit problems.2.2 Power Systems:- Power systems deal with the generation, transmission, and distribution of electrical energy.- Concepts like power generation, power factor correction, and power system protection are essential in ensuring a stable and reliable power supply.2.3 Control Systems:- Control systems involve the regulation and control of electrical processes.- Concepts like feedback control, PID (Proportional-Integral-Derivative) controllers, and system stability are crucial in designing and implementing control systems.3. Job Opportunities in Electrical Engineering and its Automation:3.1 Electrical Engineer:- Electrical engineers are responsible for designing, developing, and maintaining electrical systems.- They work in various industries, including power generation, telecommunications, and manufacturing.3.2 Automation Engineer:- Automation engineers specialize in the design and implementation of automation systems.- They develop control strategies, program PLCs, and integrate automation technologies into electrical systems.3.3 Research and Development:- Electrical engineering and its automation offer numerous research and development opportunities.- Researchers work on developing innovative technologies and improving existing systems to meet the evolving demands of industries.4. Future Prospects in Electrical Engineering and its Automation:4.1 Renewable Energy:- The growing focus on renewable energy sources, such as solar and wind power, presents new challenges and opportunities in electrical engineering and its automation.- Engineers are needed to design and optimize renewable energy systems and integrate them into the existing power grid.4.2 Internet of Things (IoT):- The integration of electrical systems with IoT technologies opens up new avenues for automation and control.- Electrical engineers can leverage IoT to develop smart grids, intelligent buildings, and efficient energy management systems.4.3 Artificial Intelligence (AI):- AI techniques, such as machine learning and neural networks, can be applied to enhance the automation capabilities of electrical systems.- Electrical engineers can explore the use of AI for predictive maintenance, fault detection, and optimization of electrical processes.Conclusion:Electrical Engineering and its Automation is a dynamic field that combines electrical engineering principles with automation technologies. It plays a crucial role in various industries and offers a wide range of job opportunities. The integration of electrical engineering with automation enables the development of advanced control systems and intelligent machines. With the increasing focus on renewable energy, IoT, and AI, the future prospects in this field are promising. As technology continues to advance, electrical engineering and its automation will continue to evolve, driving innovation and shaping the future of industries.。
电气工程及其自动化专业英语介绍
电气工程及其自动化专业英语介绍Introduction to Electrical Engineering and its AutomationElectrical engineering is a field of study that deals with the design, development, and maintenance of electrical systems and equipment. It involves the application of principles and theories from physics and mathematics to solve problems related to electricity and electronics. With the rapid advancements in technology, electrical engineering has become an integral part of various industries, including power generation, telecommunications, electronics, and automation.The study of electrical engineering equips students with a strong foundation in core subjects such as circuit analysis, electromagnetic theory, power systems, and control systems. These subjects provide students with the necessary knowledge and skills to design, analyze, and optimize electrical systems. Additionally, students also gain hands-on experience through laboratory work and practical projects, which enhance their problem-solving abilities and technical expertise.The specialization in automation within the field of electrical engineering focuses on the application of control systems and computer science to automate industrial processes. Automation plays a crucial role in improving efficiency, productivity, and safety in various industries. Students studying automation learn about programmable logic controllers (PLCs), human-machine interfaces (HMIs), robotics, and computer-aided design (CAD) software. They also acquire skills in programming languages such as C++, Python, and MATLAB, which are essential for designing and implementing automation systems.The curriculum for electrical engineering and its automation specialization covers a wide range of topics to provide students with a comprehensive understanding of the field. Some of the subjects typically included in the program are:1. Circuit Analysis: This subject focuses on the analysis of electrical circuits using techniques such as Ohm's Law, Kirchhoff's Laws, and network theorems. Students learnto analyze and solve complex circuits to determine voltage, current, and power distributions.2. Electromagnetic Theory: This subject deals with the study of electromagnetic fields and their interactions with electrical systems. Students learn about Maxwell's equations, electromagnetic wave propagation, and the behavior of electromagnetic devices such as transformers and motors.3. Power Systems: This subject covers the generation, transmission, and distribution of electrical power. Students learn about power generation technologies, power system components, and the design of electrical grids. They also study power system protection and control to ensure the reliable operation of power networks.4. Control Systems: This subject focuses on the analysis and design of control systems to regulate and optimize the behavior of dynamic systems. Students learn about feedback control, PID controllers, stability analysis, and system modeling. They also gain practical experience in designing and implementing control systems through laboratory experiments.5. Digital Electronics: This subject introduces students to the fundamentals of digital logic circuits and systems. They learn about Boolean algebra, logic gates, flip-flops, and sequential logic. Students also gain hands-on experience in designing and testing digital circuits using simulation software and hardware components.6. Automation and Robotics: This subject explores the principles and applications of automation and robotics in industrial processes. Students learn about industrial automation technologies, robotic manipulators, and sensor integration. They also study topics such as motion planning, trajectory control, and machine vision.7. Computer Programming: This subject provides students with the necessary programming skills to develop software for electrical engineering applications. Students learn programming languages such as C++, Python, and MATLAB. They also gain experience in algorithm development, data analysis, and simulation techniques.Upon graduation, students with a degree in electrical engineering and its automation specialization have excellent career prospects. They can work in various industries, including power generation companies, telecommunications firms, manufacturing companies, and automation solution providers. Job roles for electrical engineering graduates include electrical design engineer, control systems engineer, automation engineer, power systems engineer, and research scientist.In conclusion, electrical engineering and its automation specialization offer students a comprehensive understanding of electrical systems and their automation. The program equips students with theoretical knowledge, practical skills, and programming expertise to design, analyze, and optimize electrical systems. With the increasing demand for automation in various industries, graduates in this field have promising career opportunities.。
电气工程及其自动化专业英语
电气工程及其自动化专业英语Section I basic electric circuit Chapter 1 Introduction to electric circuitsNew Words and Expressions1. electrical circuit n. 电路2. voltage n. 电压，伏特3. current n. 电流，通用的, 流通的, 现在的4. current flow n. 电流5. resistor n. 电阻，电阻器6. battery n. 电池7. load n. 负载，负荷8. performance n. 性能9. circuit diagram n. 电路图10. idealized model n. 理想模型Introduction*A simple circuit and its components.*Idealized model of the circuit*Model can be changed if necessary.*summarizeIn elementary physics classes you undoubtedly have been introduced to the fundamental concepts of electricity and how real components can be put together to form an electrical circuit. A very simple circuit, for example, might consist of a battery, some wire, a switch, and an incandescent light bulb as shown in Fig.1-1. The battery supplies the energy required to force electrons around the loop, heating the filament of the bulb and causing the bulb to radiate a lot of heat and some light. Energy is transferred from a source, the battery, to a load, the bulb. ————You probably already know that the voltage of the battery and the electrical resistance of the bulb have something to do with the amount of current that will flowin the circuit. From your own practical experience you also know that no current will flow until the switch is closed. That is, for a circuit to do anything, the loop has to be completed so that electrons can flow from the battery to the bulb and then back again to the battery. And finally, you probably realize that it doesn’t much matter whether there is one foot or two feet of wire connecting the battery to the bulb, but that it probably would matter if there is a mile of wire between it and the bulb.Also shown in Fig. 1-1 is a model made up of idealized components. The battery is modeled as an ideal source that puts out a constant voltage, VB, no matter what amount of current, i, is drawn. The wires are considered to be perfect conductors that offer no resistance to current flow. The switch is assumed to be open or closed. There is no arcing of current across the gap when the switch is opened, nor is there any bounce to the switch as it makes contact on closure. The light bulb is modeled as a simple resistor, R, that never changes its value, no matter how hot it becomes or how much current is flowing throughit.Fig. 1-1 (a) A simple circuit(b) An idealized representationof the circuitFor most purposes, the idealized model shown in Fig. 1-1b is an adequate representation of the circuit; that is, our prediction of the current that will flow through the bulb whenever the switch is closed will be sufficiently accurate that we can consider the problem solved. There may be times, however, when the model is inadequate. The battery voltage, for example, may drop as more and more current is drawn, or as the battery ages. ————The light bulb’s resistance may change as it heats up, and the filament may have a bit of inductance and capacitance associated with it as well as resistance so that when the switch is closed, the current may not jump instantaneously from zero to some final, steady state value. The wires may beundersized, and some of the power delivered by the battery may be lost in the wires before it reaches the load. These subtle effects may or may not be important, depending on what we are trying to find out and how accurately we must be able to predict the performance of the circuit. If we decide they are important, we can always change the model as necessary and then proceed with the analysis. The point here is simple. The combinations of resistors, capacitors, inductors, voltage sources, current sources, and so forth, that you see in a circuit diagram are merely models of real components that comprise a real circuit, and a certain amount of judgment is required to decide how complicated the model must be before sufficiently accurate results can be obtained. For our purposes, we will be using very simple models in general, leaving many of the complications to more advanced textbooks.Chapter 2 Definitions of key electrical quantitiesNew Words and Expressionscharge n. vt. 电荷；充电nucleus n. 原子核（pl.）；nuclear adj.negative n. 否定, 负数, 底片adj.否定的, 消极的, 负的, 阴性的positive adj. [数]正的adj.[电]阳的in general 通常,大体上, 一般而言，总的说来algebraic adj. 代数的, 关于代数学的solution to the circuit problem n. 关于电路问题的解法the units of power n. 功率的单位direct current (dc) n 直流电alternating current(ac) n. 交流电sinusoidally adv. 正弦地transistor n. 晶体管Part 1 Charge and CurrentAn atom consists of a positively charged nucleus surrounded by a swarm of negatively charged electrons. The charge associated with one electron has been found to be 1.602×10−19coulombs; or, stated the other way around, one coulomb can be defined as the charge on 6.242×1018 electrons. While most of the electrons associated with an atom are tightly bound to the nucleus, good conductors, like copper, have free electrons that are sufficiently distant from their nuclei that their attraction to any particular nucleus is easily overcome. These conduction electrons are free to wander from atom to atom, and their movement constitutes an electric current.In a wire, when one coulomb’s worth of charge passes a given spot in one second, the current is defined to be one ampere (abbreviated A), named after the nineteenth-century physicist Andr’e Marie Amp`ere. That is, current i is the net rate of flow of charge q past a point, or through an area:i=d q/d t (1.1) In general, charges can be negative or positive. For example, in a neon light, positive ions move in one direction and negative electrons move in the other. Each contributes to current, and the total current is their sum. By convention, the direction of current flow is taken to be the direction that positive charges would move, whether or not positive charges happen to be in the picture. Thus, in a wire, electrons moving to the right constitute a current that flows to the left, as shown in Fig.1-2.Fig. 1-2 By convention, negative charges moving in one direction constitute a positive current flow in the opposite directionWhen charge flows at a steady rate in one direction only, the current is said to be direct current, or dc. A battery, for example, supplies direct current. When charge flows back and forth sinusoidally, it is said to be alternating current, or ac. In the United States the ac electricity delivered by tes of ac and dc are shown in Fig.1-3.(a) (b)Fig. 1-3 (a) Steady-state direct current (dc) (b) Alternating current (ac)Part 2 Kirchhoff’s Current LawTwo of the most fundamental properties of circuits were established experimentally a century and a half ago by a German professor, Gustav Robert Kirchhoff (1824–1887). The first property, known as Kirchhoff’s current law (abbreviated KCL), states that at every instant of time the sum of the currents flowing into any node of a circuit must equal the sum of the currents leaving the node, where a node is any spot where two or more wires are joined. This is a very simple, but powerful concept. It is intuitively obvious once you assert that current is the flow of charge, and that charge is conservative—neither being created nor destroyed as it enters a node. Unless charge somehow builds up at a node, which it does not, then the rate at which charge enters a node must equal the rate at which charge leaves the node.There are several alternative ways to state Kirchhoff’s current law. The most commonly used statement says that the sum of the currents flowing into a node is zero as shown in Fig. 1-4a, in which case some of those currents must have negative values while some have positive values. Equally valid would be the statement that the sum of the currents leaving a node must be zero as shown in Fig. 1-4b(again some of these currents need to have positive values and some negative). Finally, we could say that the sum of the currents entering a node equals the sum of the currents leaving a node (Fig. 1-4c). These are all equivalent as long as we understand what is meant about the direction of current flow when we indicate it with an arrow on a circuit diagram. Current that actually flows in the direction shown by the arrow is given a positive sign. Currents that actually flow in the opposite direction have negative values.Fig. 1-4 Illustrating various ways that Kirchhoff’s current law can be stated(a) The sum of the currents into a node equals zero(b) The sum of the currents leaving the node is zero(c) The sum of the currents entering a node equals the sum of the currents leaving the nodeNote that you can draw current arrows in any direction that you want—that much is arbitrary—but once having drawn the arrows, you must then write Kirchhoff’s current law in a manner that is consistent with your arrows, as has been done in Fig.1-4. The algebraic solution to the circuit problem will automatically determine whether or not your arbitrarily determined directions for currents were correct.Example 1.1 Using Kirchhoff’s Current LawA node of a circuit is shown with current direction arrows chosen arbitrarily. Having picked those directions, i1 = −5 A, i2 = 3 A, and i3 = −1 A. Write an expression for Kirchhoff’s current law and solve for i4.Solution. By Kirchhoff’s current law,i1 + i2 = i3 + i4−5 + 3 = −1 + i4so that i4 = −1 AThat is, i4 is actually 1 A flowing into the node. Note that i2, i3, and i4 are all entering the node, and i1 is the only current that is leaving the node.Part 3 Kirchhoff’s Voltage LawElectrons won’t flow through a circuit unless they are given some energy to help send them on their way. That “push”is measured in volts, where voltage is defined to be the amount of energy (w, joules) given to a unit of charge,v=dw/dq (1-2)A 12-V battery therefore gives 12 joules of energy to each coulomb of charge that it stores. Note that the charge does not actually have to move for voltage to have meaning. Voltage describes the potential for charge to do work.While currents are measured through a circuit component, voltages are measured across components. Thus, for example, it is correct to say that current through a battery is 10 A, while the voltage across that battery is 12 V. Other ways to describe the voltage across a component include whether the voltage rises across the component or drops. Thus, for example, for the simple circuit in Fig. 1-1, there is a voltage rise across the battery and voltage drop across the light bulb.V oltages are always measured with respect to something. That is, the voltage of the positive terminal of the battery is “so many volts”with respect to the negative terminal; or, the voltage at a point in a circuit is some amount with respect to some other point. In Fig. 1-5, current through a resistor results in a voltage drop from point A to point B of V AB volts. V A and VB arethe voltages at each end of theresistor, measured with respectto some other point.Fig. 1-5 The voltage drop from point A to point B is V AB, where V AB = V A −VBThe reference point for voltages in a circuit is usually designated with a ground symbol. While many circuits are actually grounded—that is, there is a path for current to flow directly into the earth—some are not (such as the battery, wires, switch, and bulb in a flashlight). When a ground symbol is shown on a circuit diagram, you should consider it to be merely a reference point at which the voltage is defined to be zero. Fig.1-6 points out how changing the node labeled as ground changes the voltages at each node in the circuit, but does not change the voltage drop across each component.The second of Kirchhoff’s fundamental laws states that the sum of the voltages around any loop of a circuit at any instant is zero. This is known as Kirchhoff’s voltage law (KVL). Just as was the case for Kirchhoff’s current law, there are alternative, but equivalent, ways of stating KVL. We can, for example, say that the sum of the voltage rises in any loop equals the sum of the voltage drops around the loop. Thus in Fig. 1-6, there is a voltage rise of 12 V across the battery and a voltage drop of 3 V across R1 and a drop of 9 V across R2. ————Notice that it doesn’t matter which node was labeled ground for this to be true. Just as was the case with Kirchhoff’s current law, we must be careful about labeling and interpreting the signs of voltages in a circuit diagram in order to write the proper version of KVL. A plus (+) sign on a circuit component indicates a reference direction under the assumption that the potential at that end of the component is higher than the voltage at the other end. Again, as long as we are consistent in writing Kirchhoff’s voltage law, the algebraic solution for the circuit will automatically take care of signs.Part 5 Summary of Principal Electrical QuantitiesThe key electrical quantities already introduced and the relevant relationships between these quantities are summarized in Table 1-1.Since electrical quantities vary over such a large range of magnitudes, you will often find yourself working with very small quantities or very large quantities. For example, the voltage created by your TV antenna may be measured in millionths of a volt (microvolts, μV), while the power generated by a large power station may be measured in billions of watts, or gigawatts (GW). To describe quantities that may take on such extreme values, it is useful to have a system of prefixes that accompany the units. The most commonly used prefixes in electrical engineering are given in Table 1-2.Table1-1 Key Electrical Quantities and RelationshipsTable 1-2 Common PrefixesPart 6 Ideal Voltage Source and Ideal Current SourceElectric circuits are made up of a relatively small number of different kinds of circuit elements, or components, which can be interconnected in an extraordinarily large number of ways. At this point in our discussion, we will concentrate on idealized characteristics of these circuitelements, realizing that real components resemble, but do not exactly duplicate, the characteristics that we describe here.An ideal voltage source is one that provides a given, known voltage vs, no matter what sort of load it is connected to. That is, regardless of the current drawn from the ideal voltage source, it will always provide the same voltage. Note that an ideal voltage source does not have to deliver a constant voltage; for example, it may produce a sinusoidally varying voltage—the key is that voltage is not a function of the amount of current drawn. A symbol for an ideal voltage source is shown in Fig. 1-7.A special case of an ideal voltage source is an ideal battery that provides a constant dc output, as shown in Fig. 1-8. A real battery approximates the ideal source; but as current increases, the output drops somewhat. To account for that drop, quite often the model used for a real battery is an ideal voltage source in series with the internal resistance of the battery.An ideal current source produces a given amount of current is no matter what load it sees. As shown in Fig. 1-9, a commonly used symbol for such a device is circle with an arrow indicating the direction of current flow. While a battery is a good approximation to an ideal voltage source, there is nothing quite so familiar that approximates an ideal current source. Some transistor circuits come close to this ideal and are often modeled with idealized current sources.Section II The electric power systemChapter 1 Brief Introduction to The Electric Power SystemPart 1 Minimum Power systemNew Words and ExpressionsMinimum a 最小prime mover n 原动机generator n 发电机load n 负载furnace n 炉膛boiler n 锅炉fissionable n 可裂变的fissionable material 核燃料reactor n 反应堆nuclear reactor核反应堆elevation n 高度，海拔internal combustion engine 内燃机steam-driven turbine 汽轮机hydraulic turbine 水轮机convert v 变换，转换shaft n 传动轴，轴torque n 力矩servomechanism n 伺服机构*Elements of a minimum electric power system*Types of energy source*Types of prime mover*Types of electrical load*Functions of the control systemA minimum electric power system is shown in Fig.1-1, the system consists of an energy source, a prime mover, a generator, and a load.The energy source may be coal, gas, or oil burned in a furnace to heat water and generate steam in a boiler; it may be fissionable material which, in a nuclear reactor, will heat water to produce steam; it may be water in a pond at an elevation above the generating station; or it may be oil or gas burned in an internal combustion engine.The prime mover may be a steam-driven turbine, a hydraulic turbine or water wheel, or an internal combustion engine. Each one of these prime movers has the ability to convert energy in the form of heat, falling water, or fuel into rotation of a shaft, which in turn will drive thegenerator.The electrical load on the generator may be lights, motors, heaters, or other devices, alone or in combination. Probably the load will vary from minute to minute as different demands occur.The control system functions （are）to keep the speed of the machines substantially constant and the voltage within prescribed limits, even though the load may change. To meet these load conditions, it is necessary for fuel input to change, for the prime mover input to vary, and for the torque on the shaft from the prime mover to change in order that the generator may be kept at constant speed. In addition, the field current to the generator must be adjusted to maintain constant output voltage. The control system may include a man stationed in the power plant who watches a set of meters on the generator output terminals and makes the necessary adjustments manually. In a modern station, the control system is a servomechanism that senses generator-output conditions and automatically makes the necessary changes in energy input and field current to hold the electrical output within certain specifications.Part 2 More Complicated Systems*Foreword*Cases of power system with out circuit breaker*Power system with circuit breakerNew Words and Expressions1. associated a 联接的2. circuit n 电路3. circuit breaker n 断路器4. deenergize vt 切断，断电5. deenergized adj 不带电的6. outage n 停电7. diagram n 简图8. switch out of 退出来，断开9. switch off v 切断，关闭In most situations the load is not directly connected to the generator terminals. More commonlythe load is some distance from the generator, requiring a power line connecting them. It is desirable to keep the electric power supply at the load within specifications. However, the controls are near the generator, which may be in another building, perhaps several miles away.If the distance from the generator to the load is considerable, it may be desirable to install transformers at the generator and at the load end, and to transmit the power over a high-voltage line (Fig.1-2). For the same power, the higher-voltage line carries less current, has lower losses for the same wire size, and provides more stable voltage.In some cases an overhead line may be unacceptable. Instead it may be advantageous to use an underground cable. With the power systems talked above, the power supply to the load must be interrupted if, for any reason, any component of the system must be moved from service for maintenance or repair.Additional system load may require more power than the generator can supply. Another generator with its associated transformers and high-voltage line might be added.It can be shown that there are some advantages in making ties between the generators (1) and at the end of the high-voltage lines (2 and 3), as shown in Fig.1-3. This system will operate satisfactorily as long as no trouble develops or no equipment needs to be taken out of service.The above system may be vastly improved by the introduction of circuit breakers, which may be opened and closed as needed. Circuit breakers added to the system, Fig.1-4, permit selected piece of equipment to switch out of service without disturbing the remainder of system. With this arrangement any element of the system may be deenergized for maintenance or repair by operation of circuit breakers. Of course, if any piece of equipment is taken out of service, then the total load must be carried by the remaining equipment. Attention must be given to avoid overloads during such circumstances. If possible, outages of equipment are scheduled at times when load requirements are below normal.Fig.1-5 shows a system in which three generators and three loads are tied together by threetransmission lines. No circuit breakers are shown in this diagram, although many would be required in such a system.Chapter 2 Faults on Power SystemNew Words and Expressions1. fault n 故障2. interference n 干扰，防碍3. exceed vt 超出，超过4. abnormal n 异常的，不规则的5. intentional n 故意的6. feed (fed) 给。
(最新整理)(完整版)电气工程及其自动化专业英语
电气工程及其自动化专业教研室
6
• The exciting or magnetizing current （励磁电流）can thus be very small. Further, the proportion of the total flux which is linked mutually by the two coils is greatly increased.
of two coils in close proximity. One coil of N1 turns is excited with
alternating current and therefore establishes a flux φ11 which alternates with the current (随时间交变）. The other coil is linked
• the applied voltage 外施电压
• zero-power-factor 零功率因数
• the no-load power factor 空载功率因数
• formulate 用公式表示,系统地阐述
• saturation 饱和
2021/7/26
电气工程及其自动化专业教研室
4
Unit 11 The Transformer on No Load
a result (因此), is called the secondary winding.
2021/7/26
电气工程及其自动化专业教研室
7
• It should not be difficult to realize that the two functions are interchangeable: if coil 2 were excited instead, a mutual e.m.f. would be induced in coil 1 which would then become the secondary winding(二次绕组).
《电气工程及其自动化》专业英语夹带
【词汇】电阻resistance；电流current；电压voltage；电容capacitance；电感inductance；电感特性exhibit inductance;频率frequency;波形waveform;绝缘体insulator；导体conductor；阻值resist；能力，性能capability；耗散dissipate；容纳accommodate；电容器capacitor；电容capacitance；电感器inductor；共振，谐振resonate；发射器emitter；整流器rectifier；波长wavelength；原子atom；质子proton；电荷，负荷charge；吸引attraction；排斥repulsion；交流发电机alternator；发电机generator；势的，位的potential终端terminal；极性polarity；正弦sine；正弦波sinewave；；周期cycle；三相threephase；偏移量offset；；电枢armature；磁场magnetic field；顶点peak；峰值peakvalue；电路ciruit；负荷，负载load；开关，电闸，转换switch；示意性的schematic；计算，考虑calculate；分子numerator；转化的invert；支流branch；混合物compound；相等的equivalent；方法method；刷新redraw；二极管diode；晶体管transistor；半导体semiconductor；制作fabricate;晶体crystal；结合物bond；四面体tetrahedron；本质的intrinsic；杂物，混杂物impurity；中等的moderate；极性polarity；交感interaction；损耗depletion；相反reverse；真空vacuum；泄漏leakage；数字的numerical；十进制decimal；阿拉伯数字digit；权重weight；幂power；二进制binary；位bit；乘multiply；余数remainder；综合integration；双极的bipolar；变极器inverter；便携式电脑laptop；描述depict；瞬间的momentary；逻辑门gate；图表的diagrammatic；方向，方位orientation；芯片chip；多路器multiplexer；定理theorem；搅拌机mixer；向量vector；摩擦力friction；扭矩torque；乘积product；半径，范围radius；杠杆lever；旋转revolution；惯性inertia；补偿compensate；功work;【短语】工业总线industrial bus;电压差voltage difference; 电压降voltage drop;串联电路series circuit; 并联电路parallel circuit; ;换向开关inverter switch；开关输入量discrete input; 正电荷positive charge；负电荷negative charge; 正向positive direction；负向negative direction；反向opposite direction；三相three-phase；磁场magnetic field;交流变量alternating current component;超时over time; 电场electric field; 峰值peak value；三角函数trigonometric function；均方根root-mean-square;等值电路equal value resistors;复合电路compound circuits; 数字转换conversion of number; 可编程控制器programmable controller；电能electrical energy；机械能mechanical energy；惯性定律law of inertia;电枢磁场armature field;右手法则right-hand rule;采样间隔sampling interval;模拟信号analog signal;数字信号digital signal;模拟量输入analog input；接近开关proximity switch;有功功率active power;放大区amplifier region;异步电动机asynchronous machine;开关量输出discrete output;三相交流电three-phase;有源滤波器active filter；在—之间between and；另一方面on the other hand；利用take advantage of；包围close in；由---组成be formed by；考虑take into account；支路by-pass；中性状态neutral state；挤出去force out；自由电子free electron；电流current flow；图示graphic representation；正弦波sine wave；；；与—有关be referable to；；最小公倍数lowest common multiple；复合电路compound circuits；并联分支parallel branch;物理类型physics types；碳族carbon family；三维的3-dimensional；外层电子outer electron；元素周期表periodic table；PN结PNjunction；N区Nregion；数字系统number system；数字值numerical value；十进制系统decimal system；二进制系统binary system；指轮开关thumb wheel switch；；超大规模集成电路very large scale integration；；真值表truth table；牵引电阻pull-up resistor；；米每秒meters per second；角速度angular speed；外力external force；转动惯量moment of inertia；蒸汽机steam engine；绕—而走walk around；欧姆定律Ohm’s law;色条代码color chart codes；国家军用规格和标准National Military specification and standard;检查和维修inspection maintenance;保修条款;limited warranty policy;原子中性状态neutral state of an atom;电中性electrically neutral;交流正弦波ACsine wave;三相交流电three-phase AC power;瞬时电压instantaneons voltage;有效值effective value;简单电路simple electric circuit;数字电路digital circuit elememts;人工布线manual routing;自动布线auto routing;静力net force；线速度linear speed;角速度angular speed;加速度acceleration;【缩写】DC(Direct Current)直流电；BCD(Binary-Coded Decimal)二进制编码的十进制；CMOS(comliementary metal oxide semiconduct)互补金属氧化物半导体；AC(Alternating Current)交流电；RPM(revolutions per minute)转/分；RF(Radio Frequency)射频，无线电频率；BCD(Binary Coded Decimal)二进制编码的十进制；CEMF（CounterElectroMotiveForce）反电动势；PID（proportional integral differential）比例积分微分；PLC （programmable logic controller）可编程逻辑控制器；ADC（analog to digital converter）·模拟/数字转换器；【翻译】1.Resistors are used to control voltagesand currents:电阻器被用于控制电压与电流2.Resistors are components that have a predetermined resistance.Resistance determines how much current will flow through a component.电阻器是预先设定好的元件。
专业是电气工程及其自动化英语
专业是电气工程及其自动化英语Electrical Engineering and Automation.Electrical engineering and automation is a branch of engineering that deals with the generation, transmission, distribution, and utilization of electrical energy. It also involves the design, development, and maintenance of automated systems.Electrical engineers are responsible for designing and maintaining electrical systems in a variety of settings, including homes, businesses, and industrial facilities. They also work on the development of new electrical technologies, such as solar and wind power.Automation engineers are responsible for designing and maintaining automated systems in a variety of settings, including factories, warehouses, and hospitals. They also work on the development of new automation technologies, such as robotics and artificial intelligence.Education.Electrical engineering and automation programstypically require students to complete coursework in mathematics, physics, and computer science. Students also take courses in electrical engineering fundamentals, such as circuit theory, electromagnetic fields, and power systems. Automation engineering students take additional courses in control theory, robotics, and artificial intelligence.Most electrical engineering and automation programs are accredited by the Accreditation Board for Engineering and Technology (ABET). ABET accreditation ensures that programs meet the highest standards of quality and that graduates are prepared to enter the workforce.Career Outlook.The job outlook for electrical engineers and automation engineers is expected to be good over the next few years.The demand for electrical engineers is expected to increase as the world becomes increasingly electrified. The demand for automation engineers is also expected to increase as businesses look to automate more of their operations.Salary.The median annual salary for electrical engineers is $97,410. The median annual salary for automation engineers is $110,140.Related Fields.Electrical engineering and automation is a relatedfield to several other engineering disciplines, including computer engineering, mechanical engineering, andindustrial engineering.Professional Societies.There are a number of professional societies that electrical engineers and automation engineers can join.These societies offer opportunities for professional development, networking, and leadership. Some of the most popular professional societies for electrical engineers and automation engineers include:Institute of Electrical and Electronics Engineers (IEEE)。
电气工程及其自动化专业英语介绍
Electrical Engineering and AutomationElectrical Engineering and Automation was created at forty years ago. AS a new subject, it is relating to many walks of life, small to a switch designed to study aerospace aircraft, has its shadow.Electrical Engineering and Automation of electrical information professional is an emerging field of science, but because of people's daily lives and industrial production is closely related to the extraordinarily rapid development of relatively more mature now. High-tech industry has become an important component of the widely used in industry, agriculture, national defense and other fields, in the national economy is playing an increasingly important role.Worse more, Electrical Engineering and Automation is very hard to learn. The graduate should obtain much knowledge and ability. Such as natural science foundations include more sturdy mathematics, physics, etc, better Humanity, social science basic for sum foreign language for integration capability. Besides the essential technological basic theory knowledge of the originally professional field, mainly include circuit, electric magnetic field theory, electronic technology, information place in system Paying attention to, control theory, computer software and hardware basic theories. And so on.Control theory and electrical network theory is a professional electrical engineering and automation of the base, power electronics technology, computer technology is its main technical means, but also includes a system analysis, system design, system development and system management anddecision-making research. There are some characteristics of the profession, that is, combining the strength of power, electrical and electronic technology, software and hardware combined with a cross-disciplinary nature, electricity, electronics, control, computer integrated multi-disciplinary, so that graduates with strong adaptation capacity.Electricity is the most important and convenient energy which the modern society depends on more heavily than ever before. Electric power system, providing electricity to the modern society, has become indispensible components of the industry world. Power system and automation researches on how to produce, transform, transmit, distribute, use, control and manage electricity. It combines the traditional electrotechology with computer science ,power electronics and automation control theory ,with board prospects for development.We quest the principle and structure of power system network in order to improve our system to provide a reliable power supply with acceptable voltages and frequency to the customers. This major contains 3 core curricula--Motor learning, Power system analysis and Relay protection.Motor learning introduces the basic equipments of power system to us such as generators, transformers and motors. It's the basis of the following two curricula.Power system analysis describes the power flow calculation , power system control(one is active power and frequency control the other is reactive power and voltage control)and power system stability(including small disturbance stability and transient sta...电气10-3班魏学军25号高考是我们人生中重要的阶段，我们要学会给高三的自己加油打气。
电气工程及其自动化专业英语第一单元课件
AC and DC electricity
AC (Alternating Current): The flow of electricity in which the direction of current changes periodically.
DC (Direct Current): The flow of electricity in which the direction of current remains constant.
02
Basic knowledge of electrical engineering
Basic concepts of circuits
Circuit
A closed path that allows current to flow.
Series and parallel circuits
Series circuits have current flow in the same direction, while parallel circuits have current flow in opposite directions.
Over time, Electrical Engineering and Automation has evolved to include a wide range of sub-fields, including power engineering, control systems, robotics, and more.
Computer control systems can be used for a wide range of applications, including industrial manufacturing, process control, aviation, and more.
电气工程及其自动化专业英语介绍
电气工程及其自动化专业英语介绍Introduction to Electrical Engineering and AutomationElectrical Engineering and Automation is a specialized field that combines electrical engineering principles with automation technologies to design, develop, and optimize electrical systems and automated processes. This field plays a crucial role in various industries, including manufacturing, power generation, transportation, telecommunications, and healthcare.1. Overview of Electrical Engineering and Automation:Electrical Engineering and Automation is a multidisciplinary field that encompasses the study of electrical circuits, power systems, control systems, electronics, robotics, and computer programming. It focuses on the application of electrical principles to design, analyze, and control electrical systems and automated processes.2. Core Concepts in Electrical Engineering and Automation:2.1 Electrical Circuits:Electrical circuits form the foundation of electrical engineering. Students learn about circuit analysis techniques, including Ohm's law, Kirchhoff's laws, and various circuit theorems. They gain knowledge of resistors, capacitors, inductors, and other electronic components.2.2 Power Systems:Power systems deal with the generation, transmission, and distribution of electrical energy. Students study power generation technologies such as thermal, hydro, nuclear, and renewable energy sources. They learn about power transmission and distribution networks, including transformers, substations, and power cables.2.3 Control Systems:Control systems involve the regulation and automation of physical processes. Students learn about feedback control theory, PID controllers, and system stability analysis. They gain knowledge of sensors, actuators, and programmable logic controllers (PLCs) used in industrial automation.2.4 Electronics:Electronics focuses on the design and analysis of electronic circuits and devices. Students study semiconductor devices such as diodes and transistors, digital logic circuits, analog and digital signal processing, and microcontrollers. They learn to design electronic circuits for various applications.2.5 Robotics and Automation:Robotics and automation involve the design and development of robotic systems and automated processes. Students learn about robot kinematics, dynamics, and control. They gain knowledge of industrial automation techniques, including robotic arms, conveyor systems, and automated assembly lines.2.6 Computer Programming:Computer programming is an essential skill in electrical engineering and automation. Students learn programming languages such as C, C++, and Python. They acquire skillsin writing code for data analysis, control algorithms, and human-machine interfaces.3. Career Opportunities:Graduates in Electrical Engineering and Automation have diverse career opportunities in various industries. Some potential career paths include:- Electrical Engineer: Designing and analyzing electrical systems, circuits, and power distribution networks.- Control Systems Engineer: Developing and implementing control systems for industrial automation and robotics.- Power Systems Engineer: Working on the design and optimization of power generation and distribution systems.- Electronics Engineer: Designing and testing electronic circuits and devices.- Automation Engineer: Developing automated processes and systems for manufacturing and industrial applications.- Research and Development Engineer: Conducting research and innovation in electrical engineering and automation technologies.4. Importance of Electrical Engineering and Automation:Electrical Engineering and Automation plays a crucial role in modern society. It enables the efficient generation, transmission, and utilization of electrical energy. It enhances industrial productivity through automation and robotics. It contributes to the development of advanced technologies such as renewable energy systems, smart grids, and autonomous vehicles. Furthermore, it plays a vital role in improving the quality of life by enabling advancements in healthcare technologies, telecommunications, and information systems.In conclusion, Electrical Engineering and Automation is a dynamic and interdisciplinary field that combines electrical engineering principles with automation technologies. It offers a wide range of career opportunities and contributes to technological advancements in various industries. By studying this field, students gain the knowledge and skills necessary to design, analyze, and optimize electrical systems and automated processes.。