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1、Chapter 3Power Electronic Technology Section 1 Semiconductor Switchessemiconductor n. 半导体power electronicn. 电力电子lossn. 损耗，损失windingn. 绕组，线圈 一圈，一转 transformer n 变压器，变换器，变量器dielectric n. 介质，电介质，绝缘材料；a. 绝缘的，介电的，介质的，不导电的 Words eddyn. 涡流，旋涡； a. 涡流的，涡旋的；v. 涡流，起旋涡hysteresis n. 磁滞，滞后，迟滞on-state a. 通态的，接通的，开
2、态off-state a. 关态的，断开的，断态的microamp n. 微安milliamp n. 毫安Words waveform n. 波形zero-voltage 电压过零的zero-current 电流过零的 Words 1The switching losses are significant and can be managed. They can be further divided into three components: (a) the on-state losses, (b) the off-state losses and the losses in the tra
3、nsition states.开关损耗是很大的，但可以控制。开关损耗进一步可以分解成三个部分：接通状态、关断状态和变换状态的损耗。Notes 2The practical switching devices have limited capabilities of rate of voltage transition and the rate of current steering. These nonabrupt transition ratesgive rise to power losses in the switching devices. We will examine these
4、switching losses in two cases separately: the inductive and capacitive loads.实际开关装置限制了电压变换速率和电流换向速率。非突变引起了开关装置的功率损失。我们将分别从感性负载和容性负载两种情况来分析开关损耗。Notes 3The switching power losses increase linearly with the switching frequency like in the resistive case but about six times more. The upper bound on the
5、switching frequency is also about half. 类似于电阻负载的情况，开关功率损耗随着开关频率线性增大，但大约为电阻负载情况的6倍多。开关频率的上限也约为一半。Notes 4The capacitor is assumed to be large so that the voltage through it in steady state is nearly constant Uo. Assume that initially the switch is on, hence, the current through the switch is IS. The c
6、apacitor voltage is Uo, the voltage across the switch is zero and the diode V1 is reverse biased. .假设电容器很大，致使在稳态状态下其两端的电压接近为常数Uo。假使开关开始处于闭合状态，则通过开关的电流为IS。电容器的电压为Uo，开关两端的电压为零，二极管V1反向偏置。Notes Exercises 课内完成section 1中的Exercises I, II and III 电力电子器件电力电子器件Power Electronic DevicePower Electronics Technolo
7、gy 电力电子技术电力电子技术 Analog Electronic Techniques 模拟电子技术模拟电子技术Semiconductors半控型器件：半控型器件：Thyristor 晶闸管晶闸管(SCR: Silicon Controlled Rectifier)全控型器件：全控型器件：GTR 晶体管晶体管 (Giant Transistor)IGBT 绝缘栅双极晶体管绝缘栅双极晶体管(Insulated-Gate Bipolar Transistor)Power MOSFET 电力场效应晶体管电力场效应晶体管(Metal Oxide Semiconductor Field Effect
8、Transistor)GTO 门极可关断晶闸管门极可关断晶闸管 (Gate-Turn-Off Thyristor)不可控器件：不可控器件：Power Diode (Semiconductor Rectifier) 电力电子器件电力电子器件Power Electronic DeviceTransition of Part of Speech 词类转换是指把原文语言中的某一词类转译为汉词类转换是指把原文语言中的某一词类转译为汉语的另一词类。语的另一词类。一、转换为汉语动词一、转换为汉语动词 1、名词转换成动词、名词转换成动词 英英语语中中表表达达动动作作概概念念的的动动名名词词、具具有有动动作作意
9、意义义的的抽抽象象名名词词、由由动动词词派派生生出出来来的的名名词词、动动词词加加名名词词构构成成的的固固定定短短语语、介介词词加加名名词词构构成成的的固固定定短短语语等等，往往往往可可以以根据具体情况译成汉语动词。根据具体情况译成汉语动词。 (1) The application of electronic computers makes for a tremendous rise in labor productivity. 使用电子计算机可以大大提高劳动生产率。 Transition of Part of Speech(2) Computers can provide analysis
10、of every operation in a factory. 计算机能对工厂的每道工序进行分析分析。(3) Primary forces have certain valuations that must be considered in any design. 在任何设计中，对于数值能确切计计算算的主要作用力都必须加以考虑。(4) Integrated circuits are fairly recent development. 集成电路是近年来发展起来发展起来的。 Transition of Part of Speech(5) Rockets have found applicati
11、on for the exploration of the universe. (6) The sight and sound of our jet planes filled me with special longing. 火箭已经火箭已经用来探索用来探索宇宙。宇宙。看到看到我们的喷气式飞机，我们的喷气式飞机，听见听见隆隆的机声，令我心驰神往。隆隆的机声，令我心驰神往。Transition of Part of Speech(7) The lack of any special excretory system is explained in a similar way. （excreto
12、ry：排泄的） (8) The 1976 UN document calls for the settlement of the Middle East conflict on the basis of Israeli withdrawal from occupied territories and Arab acknowledgement of Israelis right to exist.（n. v.） 植物植物没有没有专门的专门的排泄排泄系统，可用同样的方式加以说明。系统，可用同样的方式加以说明。（名词转译）（名词转译）（n.v.） 1976年联合国文件年联合国文件要求要求在以色列在以
13、色列撤出撤出所占的土地以及阿拉伯所占的土地以及阿拉伯承认承认以色列的生存权利的基础上以色列的生存权利的基础上解决解决中东冲突。中东冲突。Transition of Part of Speech2、形容词转换成动词、形容词转换成动词 英语中某些由动词转换来的形容词、同介词搭配构成句子表语或定语的形容词、与连系动词一起构成复合谓语的形容词，通常可译成汉语中的动词。(1) Copper wire is flexible. 铜线容易弯曲弯曲。(2) Television is different from radio in that it sends and receives pictures. 电视
14、不同于不同于无线电在于能发送并接收图像。 Transition of Part of Speech(3) If extremely low-cost power were ever to become available from large nuclear power plants, electrolytic hydrogen would become competitive. 如能从大型核电站获获得得成本极低的电力，电解氢的竞争能力就会增强。(4) Heat is a form of energy into which all other forms are convertible. 热是
15、能的一种形式，其他一切能的形式都能转转化化为热能。 (5) The workers are confident that they will be able to build the modern factory in a short time.工人们确信确信在短期内一定能建成这座现代化工厂。Transition of Part of Speech3、介词转换成动词、介词转换成动词 英语中的介词或介词短语在许多情况下可以译成汉语的动词，尤其是当它们用作表语或状语时。(1) The letter E is commonly used for electromotive force. 通常用字母E
16、表示表示电动势。(2) Except for atomic energy, all forms of energy used by man are from the sun. 除原子能之外，人类所利用的一切形式的能量都来来自自太阳。Transition of Part of Speech(3) So long as we have means of producing heat we can keep the steam engine at work. 只要能产生热，就能使蒸汽机做做功。 Transition of Part of Speech4、 副词转换成动词副词转换成动词 英语中有些作表
17、语的副词或复合宾语中的副词，往往可译成汉语的动词。(1) The electric current flows through the circuit with the switch on. 如果开关接通接通，电流就流过线路。(2) Open the valve to let air in. 打开阀门，让空气进入进入。Transition of Part of Speech(3) We are through with our test report. 我们的试验报告写写完了。 我笔直地向前高速我笔直地向前高速飞行飞行，越过港口，飞临海面。，越过港口，飞临海面。(4) I barreled s
18、traight ahead, across the harbor and out over the sea. （barrel：v.装桶；装桶；俚俚高速开车高速开车/行驶；飞奔）行驶；飞奔）Transition of Part of Speech二、转换为汉语名词二、转换为汉语名词 1、动词转换成名词、动词转换成名词 英英语语中中有有些些动动词词在在翻翻译译成成汉汉语语时时很很难难找找到到相相应应的的动词，这时可将其转译成汉语名词动词，这时可将其转译成汉语名词 。(1) The electronic computer is chiefly characterized by its accurat
19、e and rapid computations. 电子计算机的主要特点特点是计算准确而快速。(2) An electric current varies directly as the electromotive force and inversely as the resistance. 电流的变化变化与电动势成正比，与电阻成反比。 Transition of Part of Speech(3) The design aims at automatic operation, easy regulation, simple maintenance and high productivity.
20、 设计的目目的的在于自动操作，调节方便，维护简易，生产率高。(4) Formality has always characterized their relationship. （formality：拘谨；礼节；俗套） 他们之间的关系，有一个有一个特点特点，就是以礼相待。Transition of Part of Speech(5) The earth on which we live is shaped a ball. （shape：使成形；摹制；仿造） (6) Most U.S. spy satellites are designed to burn up in the earths at
21、mosphere after completing their missions. 我们居住的地球，形状形状象一个大球。（动词转译）美国绝大多数间谍卫星，按其设计设计，在完成使命后，在大气层中焚毁。Transition of Part of Speech2、形容词转换成名词、形容词转换成名词 英语中有些形容词加上定冠词the表示某一类人或物，汉译时常译成名词。另外，英语中有些表示事物特征的形容词作表语时，往往可在其后加上“性”、“度”、“体”等词，译成名词。 (1) People are so much more flexible and inventive than robots. 人类比机
22、器人更灵活灵活而且更富有创造性。(2) Some people think tomorrows computers will be intelligent. 有人认为未来的计算机就具有智能智能。 Transition of Part of Speech(3) In fission processes the fission fragments are very radioactive. 在裂变过程中，裂变碎片具有强烈的放射性放射性。 The doctor did his best to cure the sick and the wounded. 医生尽了最大的努力来治疗病号和伤员病号和伤员。
23、（形容词转换）They were considered insincere. 他们被人认为是伪君子伪君子。（insincere：不诚恳的；虚伪的；不可信任的）Transition of Part of Speech3、代词转换成名词、代词转换成名词 英语中的代词译成汉语，有时为了使译文规范，须转换为名词 。(1) Radio waves are similar to light waves except that their wave-length is much greater. 无线电波与光波相似，只不过无无线线电电波波的波长更长一些。(2) The specific resistance
24、 of iron is not so small as that of copper. 铁的电阻系数不如铜的电阻系数电阻系数那样小。 Transition of Part of Speech(3) Electricity may be produced by a generator which is turned by a motor using any of the other forms of energy. 发电机可以发电，而发发电电机机是由利用任何其他形式能量的原动机带动的。 Transition of Part of Speech4、 副词转换成名词副词转换成名词 英语中有些副词，在
25、句子中用作状语，译成汉语时可根据具体情况转换成汉语的名词 。(1) The quality of the operating system determines how useful the computer is. 操作系统的质量决定着计算机的应用效能应用效能。(2) Electromagnetic waves travel as fast as light. 电磁波传播的速度速度和光一样。 . Transition of Part of Speech4、 副词转换成名词副词转换成名词(3) The instrument is used to determine how fully the
26、batteries are charged. 这种仪表用来确定电池充电的程度程度。(4) The device is shown schematically in Figure 1. 图1所示为这种装置的简图简图。 Transition of Part of Speech三、转换为汉语形容词三、转换为汉语形容词 1、副词转换成形容词、副词转换成形容词(1) Robotics is so closely associated with cybernetics that it is sometimes mistakenly considered to be synonymous. 机器人技术与控制
27、论的联系如此密密切切，以致两者有时被错误地认为是同一回事。(2) Miniature gas detector is chiefly featured by small size, light weight, complete functions and long continuous working time. 袖珍式瓦斯检测器的主主要要特点是体积小、重量轻、功能齐全、连续工作时间长。Transition of Part of Speech(3) Gases and liquids are perfectly elastic. 气体和液体都是完全的完全的弹性体。(4) In science
28、and engineering, it is of great importance to state the laws and principles accurately. (5)The sun affects tremendously both the mind and body of a man. 在理工科方面，定律和原理的准确准确叙述非常重要。太阳对人的身体和精神都有极大的极大的影响。Transition of Part of Speech2、名词转换成汉语形容词、名词转换成汉语形容词 (1) The nuclear power system designed in China is
29、of great precision. 中国设计的核动力系统十分精确精确。(2) Electronic computers and microprocessors are of great importance to us. 电子计算机和微处理器对我们来说十分重要重要。 (3) Single crystals of high perfection are an absolute necessity for the fabrication of integrated circuits. 高度完整的单晶对于制造集成电路来说是绝对必必要要的的。 Transition of Part of Speec
30、h (4)The security and warmth of the destroyers sick bay were wonderful.（destroyer：破坏者；驱逐舰；bay：湾；飞机的舱；sick bay：船上病室/医务室；船上医疗设施的总称） (5) It is no use employing radar to detect objects in water. 驱逐舰的病室很安全安全也很温暖温暖，好极了。使用雷达探测水下目标是没有用的是没有用的。Transition of Part of Speech四、转换成汉语副词四、转换成汉语副词 1、形容词转换成汉语副词、形容词转换成
31、汉语副词 (1) The engine has given a constantly good performance. 这台发动机一直运转良好良好。(2) The same principles of low internal resistance also apply to milliammeters. 低内阻的原理同样同样适用于毫安表。Transition of Part of Speech1、形容词转换成汉语副词、形容词转换成汉语副词 (3) A graph gives a visual representation of the relationship. 图表可以直观地直观地显示要
32、说明的关系。 (4)It was a clear and unemotional exposition of the presidents reasons for willing to begin a Chinese-American dialogue. （n.v.） 这篇发言清楚明白地清楚明白地、心平气和地心平气和地说明了总统希望开始中美对话的原因。（形容词转译成副词）（unemotional：无感情的；不易动感情的；exposition：事实、想法等的阐述，讲解；说明性的文章/讲话）Transition of Part of Speech2、其他词转换成副词、其他词转换成副词(1) Rap
33、id evaporation at the heating-surface tends to make the steam wet. 加热面上的迅速蒸发，往往往往使蒸汽的湿度加大。(2) The added device will ensure accessibility for part loading and unloading. 增添这种装置将保证工件装卸方便方便。 (3) We shall develop the electric power industry in a way. 我们将大规模大规模发展电力工业。 Transition of Part of Speech五、其他类型转换
34、五、其他类型转换 (1)The President had prepared meticulously for his journey. 总统为这次出访作了十分周密周密的准备。（ad. a.）（meticulously：过分注意细节的；谨小慎微的；一丝不苟地；严谨地）（2） People should have some basic idea of how the things that they use do what they do. （how表示手段）人们应该对他们使用的工具工具的操作原理操作原理/方法方法有些基本的了解。Transition of Part of Speech五、其他类
35、型转换五、其他类型转换（3） There is another conversation which from our point of view is equally important, and that is to do not with what is read but with how it is read.（what表示阅读内容；how表示阅读方法；point of view：mind） 有另一种在我们看来是同等重要的谈话，它与读的内容内容无关，而而与读的方式方式相关。Transition of Part of Speech五、其他类型转换五、其他类型转换（4） In societies where social roles are rigidly determined, boys pattern their play after the activities of their fathers and girls (play) after the tasks of their mothers. (pattern：仿照)抽支烟我会好受些。(v. a.)（增词）（5） A cigarette may comfort（vt.）me.在社会角色被严格限定的社会里,男孩仿效仿效父亲的行为游戏游戏,而女孩则模仿模仿母亲做的事情玩耍玩耍。（n. v.）Chapter 3End
