电气工程专业英语+unt1教学课件.ppt
- 【下载声明】
1. 本站全部试题类文档,若标题没写含答案,则无答案;标题注明含答案的文档,主观题也可能无答案。请谨慎下单,一旦售出,不予退换。
2. 本站全部PPT文档均不含视频和音频,PPT中出现的音频或视频标识(或文字)仅表示流程,实际无音频或视频文件。请谨慎下单,一旦售出,不予退换。
3. 本页资料《电气工程专业英语+unt1教学课件.ppt》由用户(晟晟文业)主动上传,其收益全归该用户。163文库仅提供信息存储空间,仅对该用户上传内容的表现方式做保护处理,对上传内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知163文库(点击联系客服),我们立即给予删除!
4. 请根据预览情况,自愿下载本文。本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
5. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007及以上版本和PDF阅读器,压缩文件请下载最新的WinRAR软件解压。
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 电气工程 专业 英语 unt1 教学 课件
- 资源描述:
-
1、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主编主编 杨勇杨勇 邓秋玲邓秋玲1 CONTENTS Unit 1 Fundamentals of Electronic Circuits Unit 2 Power Electronics Unit 3 Electrical MachinesUnit 4 Electric Power Systems Unit 5 Electric Power Generations Unit 6 Automatic Control Unit 7 Sensoring Technology Unit 8 Computer Network and Networke
2、d Control Unit 9 Signal Processing 2Unit 1 Fundamentals of Electronic Circuits Unit 1 Fundamentals of Electronic Circuits 1.1 Introduction to Circuit Theory 1.1 Introduction to Circuit Theory 1.2 Analog and Digital Circuits 1.2 Analog and Digital Circuits 1.3 Three-Phase Circuits1.3 Three-Phase Circ
3、uits1.4 Further Reading1.4 Further Reading31.1 Introduction to Circuit TheoryNew Words and Expressionse element n.成分成分;元件元件i interconnect vt.使互相连接使互相连接n node n n.节点节点b branch n n.分枝;分部;支流分枝;分部;支流 v v.出现分歧出现分歧l loop n.循环,回路循环,回路;vt.使成环;使成环;t topology n n.拓扑;布局;拓扑学拓扑;布局;拓扑学c configuration n n.构造;结构;配置
4、;外形构造;结构;配置;外形 t terminal n n.终点站;终端;接线端终点站;终端;接线端41.1 Introduction to Circuit TheoryNew Words and Expressionsresistor n.电电电阻器电阻器independent adj.独立自主的;不受约束的独立自主的;不受约束的series n.连续;系列;级数;串联连续;系列;级数;串联parallel adj.平行的;并联的平行的;并联的 n.平行线;平平行线;平 行面;行面;v.相应;平行相应;平行impedance n.电电阻抗;全电阻;阻抗;全电阻;物物阻抗阻抗theorem n
5、.数数定理;法则定理;法则5NoteNote:providing one or more closed paths为为network的后置定语。的后置定语。1.1 Introduction to Circuit Theory textNoteNote:differentiate在此处为动词,在此处为动词,differentiate between A A and B B表示区分表示区分A和和B;To differentiate between a circuit and a network是目的状语从句是目的状语从句.NoteNote:regard as表示表示“把把认为认为”(1)Nodes
6、,Branches and Loops Since the elements of an electric circuit can be interconnected in several ways,we need to understand some basic concepts of network topology.To differentiate between a circuit and a network,we may regard a network as an interconnection of elements or devices,whereas a circuit is
7、 a network providing one or more closed paths.61.1 Introduction to Circuit Theory textIn network topology,we study the properties relating to(关于关于.的特性的特性)the placement of elements in the network and the geometric configuration of the network.Such elements include branches,nodes,and loops.A branch re
8、presents a single element such as a voltage source or a resistor.In other words,a branch represents any two-terminal element.The circuit in Fig.1.1 has five branches,namely,the 10V voltage source,the 2A current source,and the three resistors.A node is the point of connection between two or more bran
9、ches.71.1 Introduction to Circuit Theory textA node is usually indicated by a dot in a circuit.If a short circuit(a connecting wire)connects two nodes,the two nodes constitute a single node.The circuit in Fig.1.1 has three nodes a,b,and c.Notice that the three points that form node b are connected b
10、y perfectly conducting wires and therefore constitute a single point.Note:Note:t three points that form node b 表示表示形成节点形成节点b b的的3个点个点.此句可译为此句可译为:注意到形成节点注意到形成节点b b的的3个点是通过理个点是通过理想导线相连接的,因此组成了想导线相连接的,因此组成了1个节点个节点.81.1 Introduction to Circuit Theory textThe same is true of the four points forming node
11、c.We demonstrate that(证明)the circuit in Fig.1.1 has only three nodes by redrawing the circuit in Fig.1.2.The two circuits in Fig.1.1 and Fig.1.2 are identical.However,for the sake of clarity,nodes b and c are spread out with perfect conductors as in Fig.1.2.Note::the same is true of:这也适用于这也适用于,也是如此。
12、也是如此。Note::for the sake of clarity:为清楚起见为清楚起见;:spread out:伸展伸展;spread out with perfect conductors:用理想导线分散开。:用理想导线分散开。91.1 Introduction to Circuit Theory textA loop is any closed path in a circuit.A loop is a closed path formed by starting at a node,passing through a set of nodes,and returning to the
13、 starting node without passing through any node more than once.A loop is said to be(可认为是)independent if it contains a branch which is not in any other loop.Independent loops or paths result in(导致导致,结果是)结果是)independent sets of equations.Note::回路回路是一个是一个闭合闭合的的路径路径,它是,它是从一个从一个节节点开点开始,经过若干始,经过若干节节点,再回到起
14、始点,再回到起始节节点,点,任意一个节点只经任意一个节点只经过一次过一次。101.1 Introduction to Circuit Theory textFor example,the closed path abca containing the 2 resistor in Fig.1.2 is a loop.Another loop is the closed path bcb containing the 3 resistor and the current source.Although one can identify six loops in Fig.1.2,only three
15、 of them are independent.A network with b branches,n nodes,and l independent loops will satisfy the fundamental theorem of network topology:b=l+n-1(1.1)Note:containing the 2 resistor 作定语修饰作定语修饰 closed path abca,意为包含意为包含2电阻的闭合路径电阻的闭合路径abca。111.1 Introduction to Circuit Theory textAs the next two defi
16、nitions show,circuit topology is of great value(=is very valuable)to the study of voltages and currents in an electric circuit.Two or more elements are in series(串联)(串联)if they are cascaded or connected sequentially(接顺序连接)(接顺序连接)and consequently carry the same current(流过相同电流流过相同电流).Two or more eleme
17、nts are in parallel(并联并联)if they are connected to the same two nodes and consequently have the same voltage across them.Note:Note::voltage across them表示关于两节点之间的电压,表示关于两节点之间的电压,“them”指代指代“two nodes”。121.1 Introduction to Circuit Theory textElements may be connected in a way that they are either in se
18、ries or in parallel.In the circuit shown in Fig.1.1,the voltage source and the 5 resistor are in series because the same current will flow through them.The 2 resistor,the 3 resistor,and the current source are in parallel because they are connected to the same two nodes(b and c)and consequently have
19、the same voltage across them.The 5 and 2 resistors are neither in series nor in parallel with each other.Note:修饰电流的介词短语用修饰电流的介词短语用through,:修饰电压修饰电压用用across。them代表代表 resistors131.1 Introduction to Circuit Theory text(2)Ohms Law,Kirchhoffs Current Law(KCL)and Kirchhoffs Voltage Law(KVL)Ohms Law states
20、 the voltage across a resistor,R(or impedance,Z)is directly proportional to(与.成比例)the current passing through it(the resistance/impedance is the proportionality constant).(1.2)Note:Note::proportionality constant是比例系数。是比例系数。:DC:表示表示direct current;AC表示表示alternating current。DC:AC:viRVIZ141.1 Introducti
21、on to Circuit Theory textOhms Law by itself is not sufficient to analyze circuits.However,when it is coupled with Kirchhoffs two laws,we have a sufficient,powerful set of tools for analyzing a large variety of electric circuits.Kirchhoffs laws were first introduced in 1847 by the German physicist Gu
22、stav Robert Kirchhoff(18241887).These laws are formally known as Kirchhoffs Current Law(KCL)and Kirchhoffs Voltage Law(KVL).Note:Note:by itself:本身;:本身;is coupled with:加上,与加上,与.结结合起来。合起来。are formally known as:被正式称为。:被正式称为。151.1 Introduction to Circuit Theory textKirchhoffs First Law is based on the l
23、aw of conservation of charge,which requires that the algebraic sum(代数和代数和)of charges within a system cannot change.Kirchhoffs Current Law(KCL)states that the algebraic sum of currents entering a node(or a closed boundary)is zero.Kirchhoffs First Law:基尔霍夫第一定律;:基尔霍夫第一定律;law of conservation of charge:电
24、荷守恒定律:电荷守恒定律.161.1 Introduction to Circuit Theory textMathematically,KCL implies that:(1.3)where N is the number of branches(支路数)connected to the node and in is the nth current entering(or leaving)the node.By this law,currents entering a node may be regarded as positive,while currents leaving the no
25、de may be taken as(可认为是)negative or vice versa.Note:Note:By this law:根据这个定律;根据这个定律;vice versa:反过来也一样;反之亦然。:反过来也一样;反之亦然。10Nnni171.1 Introduction to Circuit Theory textConsider the node in Fig.1.3.Applying KCL gives:i1-i2+i3+i4-i5=0 (1.4)since currents i1,i3,and i4 are entering the node,while currents
展开阅读全文