电气英文论文
Page1 Generators and Motors
From reference 1
1. Direct-current generators impress on the line a direct or continuous emf, one that is always in the same direction. Commercial dc generators have commutators, which distinguish them from ac generators. The function of a commutator and the elementary ideas of generation of emf and commutation are discussed in Div. 1. Additional information about commutation as applied to dc motors, which in general is true for dc generators, is given below.
2. Excitation of generator fields. To generate an emf, conductors must cut a magnetic field which in commercial machines must be relatively strong. A permanent magnet can be used for producing such a field in a generator of small output, such as a telephone magneto or the magneto of an insulation tester, but in generators for light and power the field is produced by electromagnets, which may be excited by the machine itself or be separately excited from another
source.Self-excited machines may be of the series, shunt, or compound type, depending upon the manner of connecting the field winding to the armature. In the series type of machine,the field winding (the winding which produces the magnetic field) is connected in series with the armature winding. In the shunt type, the field winding is connected in parallel,shunt, with the armature winding. Compound machines have two field windings on each pole. One of these windings is connected in series with the armature winding, and the other is connected in parallel or shunt with the armature winding.
3. Armature winding of dc machines may be of the lap or the wave type. The difference in the two types is in the manner of connecting the armature coils to the commutator.A coil is the portion of the armature winding between successive connections to the commutator.In the lap type of winding (see Fig. 7.1) the two ends of a coil are connected to adjacent commutator segments. In the wave type of winding (see Fig. 7.2) the two ends of a coil are connected to commutator segments that are displaced from each other by approximately 360 electrical degrees.The type
of armature winding employed affects the voltage and current capacity of the machine but has no effect upon the power capacity. This is due to the fact that the number of parallel paths between armature terminals is affected by the type of winding. For a wavewound machine there are always two paths in parallel in the armature winding between armature terminals. For a lap-wound machine there are as many parallel paths in the armature winding as there are pairs of poles on the machine. For the same number and size of armature conductors, a machine when wave-connected would generate a voltage that would equal the voltage generated when lap-connected times the number of pairs of poles.But the current capacity would be decreased in the same proportion that the voltage was increased. The current capacity of a machine when wave-connected is therefore equal to the capacity when lap-connected divided by the number of pairs of poles.
4. The value of the voltage generated by a dc machine depends upon the armature winding, the speed, and the field current. For a given machine, therefore, the voltage generated can be controlled by adjusting either the speed or the field current. Since generators are usually operated at a constant speed, the voltage must be controlled by adjusting the field current.
5. Separately excited dc generators are used for electroplating and for other electrolytic work for which the polarity of a machine must not be reversed.
Self-excited machines may change their polarities. The essential diagrams are shown in Fig. 7.3. The fields can be excited from any dc constant-potential source, such as a storage battery, or from a rectifier connected to an ac supply.The field magnets can be wound for any voltage because they have no electric connection with the armature. With a constant field excitation, the voltage will drop slightly fromno load to full load because of armature drop and armature reaction.Separate excitation is advantageous when the voltage generated by the machine is not suitable for field excitation. This is true for especially low- or high-voltage machines.
6. Series-wound generators have their armature winding, field coils, and external circuit connected in series with each other so that the same current flows
电气专业英语论文
Page1 Electrical Energy Transmission（电能输送） From reference 1 Growing populations and industrializing countries create huge needs for electrical energy. Unfortunately, electricity is not always used in the same place that it is produced, meaning long-distance transmission lines and distribution systems are necessary. But transmitting electricity over distance and via networks involves energy loss. So, with growing demand comes the need to minimize this loss to achieve two main goals: reduce resource consumption while delivering more power to users. Reducing consumption can be done in at least two ways: deliver electrical energy more efficiently and change consumer habits. Transmission and distribution of electrical energy require cables and power transformers, which create three types of energy loss: the Joule effect, where energy is lost as heat in the conductor (a copper wire, for example); magnetic losses, where energy dissipates into a magnetic field; the dielectric effect, where energy is absorbed in the insulating material. The Joule effect in transmission cables accounts for losses of about 2.5 % while the losses in transformers range between 1 % and 2 % (depending on the type and ratings of the transformer). So, saving just 1 % on the electrical energy produced by a power plant of 1 000 megawatts means transmitting 10 MW more to consumers, which is far from negligible: with the same energy we can supply 1 000 - 2 000 more homes. Changing consumer habits involves awareness-raising programmers, often undertaken by governments or activist groups. Simple things, such as turning off lights in unoccupied rooms, or switching off the television at night (not just putting it into standby mode), or setting tasks such as laundry for non-peak hours are but a few examples among the myriad of possibilities. On the energy production side, building more efficient transmission and
毕业论文(英文翻译)排版格式
英文翻译说明 1. 英文翻译文章输成word，5号新罗马（New Times Roman）字体，1.5倍行间距，将来方便打印和一起装订；英文中的图表要重新画，禁止截图。 2. 整篇论文1.5倍行间距，打印时，用B5纸，版面上空2.5cm，下空2cm，左空2.5cm，右空2cm（左装订）。 3. 论文翻译后的摘要用五号宋体，正文小四号宋体、英文和数字用新罗马（New Times Roman）12、参考文献的内容用五号字体。图和表头用五号字体加粗并居中，图和表中的内容用五号字体。论文翻译的作者用五号字体加粗。 论文大标题………小三号黑体、加黑、居中 第二层次的题序和标题………小四号黑体、加黑、居中 第三层次的题序和标题………小四号宋体、加黑、居中 正文……………………………小四号宋体、英文用新罗马12 页码……………………………小五号居中，页码两边不加修饰符 4. 论文中参考文献严格按照下述排版。 专著格式：序号.编著者.书名[M].出版地: 出版社, 年代, 起止页码 期刊论文格式：序号.作者.论文名称[J]. 期刊名称, 年度, 卷(期): 起止页码 学位论文格式：序号.作者.学位论文名称[D]. 发表地: 学位授予单位, 年度 例子: (1).胡千庭, 邹银辉, 文光才等. 瓦斯含量法预测突出危险新技术[J]. 煤炭学报, 2007.32(3): 276-280. (2). 胡千庭. 煤与瓦斯突出的力学作用机理及应用研究[D]. 北京: 中国矿业大学(北京), 2007. (3). 程伟. 煤与瓦斯突出危险性预测及防治技术[M]. 徐州: 中国矿业大学出版社, 2003.
英语毕业论文
英语毕业论文 学历、学位证明。主要是大学、研究生毕业证书，硕士学位证书，博士学位证书。 范例1：大学毕业证书 let it be known that mr. wen huang, native of jiangsu province, born on august 30, 1973, having specialized in marketing in the department of economics management from sept.1995 to july 1998 and having pleted the four year undergraduate program with qualified standing,is hereby awarded this certificate of graduation. 范例2：大学学位证书 this is to certify that mr. wen huang, born in jiangsu province on august 30, 1973 has studied for 4 years (from sept.1995 to july 1998) in the department of economics management majoring in marketing,has pleted all the courses prescribed in the teaching program, and has passed all the exams necessary for graduation from nanjing niversity. having fulfilled the requirements stipulated by the academic degree regulations of the people's republic of china, he/she is awarded the degree of bachelor of business.
电气外文文献-翻译
Circuit breaker 断路器 Compressed air circuit breaker is a mechanical switch equipment, can be i 空气压缩断路器是一种机械开关设备，能够在n normal and special conditions breaking current (such as short circuit cur 正常和特殊情况下开断电流（比如说短路电流）。 rent). For example, air circuit breaker, oil circuit breaker, interference circ 例如空气断路器、油断路器，干扰电路的导体uit conductor for the application of the safety and reliability of the circuit 干扰电路的导体因该安全可靠的应用于其中， breaker, current in arc from is usually divided into the following grades: a 电流断路器按灭弧远离通常被分为如下等级：ir switch circuit breaker, oil circuit breaker, less oil circuit breaker, compr 空气开关断路器、油断路器、少油断路器、压缩空essed air circuit breaker, a degaussing of isolating switch, six sulfur hexaf 气断路器、具有消磁性质的隔离开关、六氟luoride circuit breaker and vacuum breaker. Their parameters of voltage, 化硫断路器和真空断路器。他们的参数有电压等级、current, insulation level of breaking capacity, instantaneous voltage off ti 开断容量的电流、绝缘等级开断时间的瞬时电压恢复和me of recovery and a bombing. Breaker plate usually include: 1 the maxi 轰炸时间。断路器的铭牌通常包括： 1.最大可承
英语毕业论文选题(完整版)
英语论文选题 英语语言学 1. A Study of Adverbs in Legal English 2.Linguistic Features of Legal English 3.On Cultural Context in Legal English Articles 4.Sources of Chinese and English Legal Terms 5.Characteristics of Legal Terms 6.Functions of Languages in Legislation 7.Killing and its Hyponyms in Legal English 8.Punctuation in Legal English: for instance, comma, period, colon, etc. 9.Abbreviations in Legal English 10.Transitional Words in Legal English 11.The Application of the Fuzzy Words in Legal English法律语言模糊性词语的运用 12.The Differences of the Legal Discourse in Chinese and English英汉法律语篇的结构差异 13.On Abbreviations in Business English谈经贸英语中的缩略语现象 14.On the Multi-discipline of the Economic English V ocabulary论经济英语语汇的多学科性 15.On the Features of Business English Letters浅谈外经贸英语信函的写作特点 16.Adjusting the Tone in International Business English经贸英语缓和口吻表达方法探究 17.The Stylistic Features of the Contract English协议、合同英语的文体特点 18.On Modifiers of Nouns in English for Foreign Economy & Trade略谈外经贸英语中的名词 修饰语 19.The Negative and Active Function of Fuzzy Language in Business Writing论模糊语言在经 贸英语写作中的作用 20.The Application of PP (Polite Principle) in Business English Communication 21.CP（Cooperative Principle）and Business English Interpretation 22.Sexism as Reflected in the Chinese and English Languages 23.Lexical Items as Means of Cohesion in English Texts 24.Remarks on Modern American Slang 25.Stylistic Comparison Between Broadcast News and Newspaper News 26.News Headlines: Their Features and Style 27.A Comparative Study of English and Chinese Prepositions 28.Death Metaphors in English 29.The Pragmatic Functions of Intonation for Language Acquisition 30.The Change of English Word Meaning: Factors and Types 31.A Study of Transitional Words and Expressions 过渡词及表达法的研究 32.Euphemistic Expressions in Foreign Affairs 外事用语中的委婉表达
纯英语毕业论文范文
XX学院本科生英语专业毕业论文装订顺序（APA格式）（注：此格式用于文学、翻译方向之外的所有论文） 1.毕业论文封面（汉语） 2.毕业论文首页（英语） 3.致谢（英文） 4.毕业论文中文摘要及关键词 5.毕业论文英文摘要及关键词 6.目录 7.正文 8.尾注（可选） 9.参考文献（英语文献在前，汉语文献在后） 10.附录（可选） 附：论文模板（模板内容仅供参考，毕业生可根据实际情况填写）
学号：00 系 名 专 业 名 称： 年 级： 姓 名： 指 导 教 师： 2008 年 5 月 日
The Use of Linking Adverbials by Chinese College English Learners A Thesis Submitted to Faculty of International Studies of Henan Normal University in Partial Fulfillment of the Requirements for the Degree of Bachelor of Arts By Liu Hiatao Supervisor：Li Qingdong May 5, 2008
文档来源为: .欢迎下载支持. like to thank all those who have given me their generous helps, commitment and enthusiasm, which have been the major driving force to complete the current paper. … 多使用的倾向。影响中国大学英语学习者使用连接副词的因素是多方面的，如母 (
电气专业英文文献.doc
电气专业英文文献
An Expert System for Transformer Fault Diagnosis Using Dissolved Gas Analysis 1. INTRODUCTION The power transformer is a major apparatus in a power system, and its correct functioning its vital to minimize system outages, many devices have evolved to monitor the serviceability of power transformers. These devices, such as, Buchholz relays or differential relays, respond only to a severe power failure requiring immediate removal of the transformer from service, in which case, outages are inevitable. Thus, preventive techniques for early detection faults to avoid outages would be valuable. In this way, analysis of the mixture of the faulty gases dissolved in insulation oil of power transformer has received worldwide recognition as an effective method for the detection of oncipient faults. Many researchers and electrical utilities have reported on their experience and developed interpretative criteria on the basis of DGA. However, criteria tend to vary from utility to utility. Therefore, transformer diagnosis is still in the heuristic stage. For this reason, knowledge-based programming is a suitable approach to implement in such a diagnostic problem. Based on the interpretation of DGA, a prototype of an expert system for diagnosis of suspected transformer faults and their maintenance procedures is proposed. The significant source in this knowledge base is the gas ratio method. Some limitations of this approach are overcome by incorporating the diagnostic procedure and the synthetic expertise method. Furthermore, data bases adopted from TPC'S gas records of transformers are incorporated into the expert system to increase the practical performance. Uncertainty of diagnosis is managed by using fuzzy set concepts. This expert system is constructed with rule based knowledge representation, since it can be expressed by experts. The expert system building tool,knowledge Engineering System(KES), is used in the development of the knowledge system because, it has excellent man-machine interface that provides suggestions. Moreover,its inference strategy is similar to
英语毕业论文范文
英语毕业论文范文 1 毕业设计(论文) 首行居中，小二号字，粗体 Introduction 论文正文段落，首行缩进4个字母，Times New Roman字体，小四号，1.25倍行距空一行 Although literary translation as an activity is as old as any cultural activity that man has known, literary translation as an academic discipline is of recent origin. It is generally believed that it began with James Holmes, who made the founding statement in his paper entitled “The Name and Nature of Translation Studies” which he presented in 1972 at the Third International Congress of Applied Linguistics in Copenhagen. (James Holmes, 1972:55) Literary translation plays an indispensable and irreplaceable role in communication across language and cultures. As far as its basic definition is concerned, the major task of literary translation is to turn the cultural content in one language into another, so whether it is faithful or not largely depends on the degrees of the translator’s grasp of the two languages and the subtle difference of the cultural content expressed in the languages. Thus literary translation will inevitably encounter the problem of culture and its representations. To deal with this problem, theorists have come up with two kinds of approaches that have aroused heated debates. This thesis sets out to study the two strategies on literary translation across the linguistic
电气专业英文文献
An Expert System for Transformer Fault Diagnosis Using Dissolved Gas Analysis 1. INTRODUCTION The power transformer is a major apparatus in a power system, and its correct functioning its vital to minimize system outages, many devices have evolved to monitor the serviceability of power transformers. These devices, such as, Buchholz relays or differential relays, respond only to a severe power failure requiring immediate removal of the transformer from service, in which case, outages are inevitable. Thus, preventive techniques for early detection faults to avoid outages would be valuable. In this way, analysis of the mixture of the faulty gases dissolved in insulation oil of power transformer has received worldwide recognition as an effective method for the detection of oncipient faults. Many researchers and electrical utilities have reported on their experience and developed interpretative criteria on the basis of DGA. However, criteria tend to vary from utility to utility. Therefore, transformer diagnosis is still in the heuristic stage. For this reason, knowledge-based programming is a suitable approach to implement in such a diagnostic problem. Based on the interpretation of DGA, a prototype of an expert system for diagnosis of suspected transformer faults and their maintenance procedures is proposed. The significant source in this knowledge base is the gas ratio method. Some limitations of this approach are overcome by incorporating the diagnostic procedure and the synthetic expertise method. Furthermore, data bases adopted from TPC'S gas records of transformers are incorporated into the expert system to increase the practical performance. Uncertainty of diagnosis is managed by using fuzzy set concepts. This expert system is constructed with rule based knowledge representation, since it can be expressed by experts. The expert system building tool,knowledge Engineering System(KES), is used in the development of the knowledge system because, it has excellent man-machine interface that provides suggestions. Moreover,its inference strategy is similar to the MYCIN. A famous rule-based expert system used for medical diagnosis. The uncertainty of human qualitative diagnostic expertise, e.g., key gas
电气工程及其自动化专业_外文文献_英文文献_外文翻译_plc方面
1、 外文原文 A: Fundamentals of Single-chip Microcomputer Th e si ng le -c hi p m ic ro co mp ut er i s t he c ul mi na ti on of both t h e de ve lo pm en t o f t he d ig it al co m pu te r an d th e i n te gr at ed c i rc ui t a rg ua bl y t h e to w m os t s ig ni f ic an t i nv en ti on s o f t he 20th c e nt ur y [1]. Th es e t ow ty pe s of ar ch it ec tu re a re fo un d i n s in g le -ch i p m i cr oc om pu te r. So m e em pl oy t he spl i t pr og ra m/da ta m e mo ry o f th e H a rv ar d ar ch it ect u re , sh ow n in Fi g.3-5A -1, o th ers fo ll ow t he p h il os op hy , wi del y a da pt ed f or ge n er al -p ur po se co m pu te rs a nd m i cr op ro ce ss o r s, o f ma ki ng n o log i ca l di st in ct ion be tw ee n p r og ra m an d d at a m e mo ry a s i n t he P r in ce to n ar ch ite c tu re , sh ow n i n F ig.3-5A-2. In g en er al te r ms a s in gl e -chi p m ic ro co mp ut er i s c h ar ac te ri ze d b y t h e i nc or po ra ti on o f a ll t he un it s of a co mp uter i n to a s in gl e d ev i ce , as s ho wn in Fi g3-5A -3. Fig.3-5A-1 A Harvard type Program memory Data memory CPU Input& Output unit memory CPU Input& Output unit
电气英文文献+翻译
POWER SUPPLY AND DISTRIBUTION SYSTEM ABSTRACT The basic function of the electric power system is to transport the electric power towards customers. The l0kV electric distribution net is a key point that connects the power supply with the electricity using on the industry, business and daily-life. For the electric power, allcostumers expect to pay the lowest price for the highest reliability, but don't consider that it's self-contradictory in the co-existence of economy and reliable.To improve the reliability of the power supply network, we must increase the investment cost of the network construction But, if the cost that improve the reliability of the network construction, but the investment on this kind of construction would be worthless if the reducing loss is on the power-off is less than the increasing investment on improving the reliability .Thus we find out a balance point to make the most economic,between the investment and the loss by calculating the investment on power net and the loss brought from power-off. KEYWARDS：power supply and distribution,power distribution reliability，reactive compensation,load distribution
英语毕业论文格式
英文版 1、论文题目要与题目审批表，开题报告严格一致。页边距设置为：左页边距为3.0厘米，右页边距为2.0厘米，上下页边距为2.5厘米； 2、各级标题的序号用阿拉伯数字表示，例如：1.，1.1，1.1.1；2.，2.1，2.1.1…… 3、所有英文均采用Times New Roman字体。其中一级标题为3号加粗；二级标题为小3号加粗；三级标题为4号加粗。 4、正文字体为Times New Roman，小4号，单倍行距，每段第一行空4字符。页码居右。 5、关键词[Key Words]用Times New Roman字体，加粗，小4号字体，各关键词之间用分号隔开。 5、注释可采用尾注或夹注，不能用脚注。 6、参考文献（即References一词）用Times New Roman字体，3号，居中，加粗；参考书目的序号用方括号（如[1]，[2]）等字体为Times New Roman5号，宋体5号字。其他格式与汉语版论文参考书目的格式相同。 7、论文封面用学校的统一封面，请去掉（设计）两个字。封面上所填信息均左对齐（其中“年级、班”的填写为“200X级（X）班”，“专业（方向）”的填写格式为“英语（国际商务）”），英语论文题目用英语，英文摘要页在前，中文摘要页在后，目录（即Contents一词）为Times New Roman字体，3号加粗，目录页的各级标题统一用小4号Times New Roman字体。页码从正文开始标注。 8、论文的附表（包括指导教师评语表、答辩委员会评语表）按“兰州商学院本科生毕业论文（设计）规范样式”执行。指导教师和评阅教师需要填写评阅表，评阅意见可以是电子打印，但必须手写签名。 9.学生论文最后装订材料包括： 1）题目审批表2）开题报告3）教师评阅表（含指导教师和评阅教师） 4）答辩成绩表5）正文 填写范版如下： 封面填写范式：
2017英语毕业论文提纲.doc
2017英语毕业论文提纲 1 introduction 1.1 significance of the research 1.2 organization of the thesis 2 literature review 2.1 researches on monolingual mental lexicon 2.1.1 definition of mental lexicon 2.1.2 models of mental lexicon: a developing one 2.2 research methodology of bilingual mental lexicon 2.2.1 word association paradigm 2.2.2 word translation task 2.2.3 cross-language priming paradigm 2.3 theories on bilingual mental lexicon 2.3.1 weinreich’s three hypotheses: the ancestor of bilingual mental lexicon models 2.3.2 paivio’s bilingual dual-coding theory 2.3.3 kroll & stewart’s revised hierarchical model 2.3.4 de groot’s distributed representation model 3 extended bilingual distributed representation model 3.1 setting and characteristic of l2 word acquisition
电气专业毕设英文文献(格式已修改)
本科毕业设计 外文文献及译文 文献题目：Direct Torque Control of Induction Motors Utilizing Three-Level Voltage Source Inverters 文献作者： Xavier del Toro Garcia, Antoni Arias, Marcel G、Jayne and Phil A、 Witting 文献来源： IEEE Trans、 Ind、 Electron, vol、 51，No、4，pp、 744–757 发表日期：2004年8月 班级： 姓名： 学号： 指导教师： 翻译日期：
英文原文： Direct Torque Control of Induction Motors Utilizing Three-Level Voltage Source Inverters Xavier del Toro Garcia, Antoni Arias, Marcel G、 Jayne, and Phil A、 Witting Abstract—A new control strategy for induction motors based on direct torque control is presented which employs a three-level inverter instead of the standard two-level inverter、 The controller is designed to achieve a torque ripple reduction by taking advantage of the increase in the number of inverter states available in a three-level inverter、The harmonic distortion in the stator currents and the switching frequency of the semi-conductor devices are also reduced in the new control system presented、 Index Terms—Induction motor drives, three-level converter, torque control、 I、 INTRODUCTION The standard voltage source inverter (VSI) traditionally used in electrical drive systems is the two-level VSI, which unfortunately has a number of inherent limitations、 For example, the maximum voltage that can be supported by the semiconductor switching devices in the VSI limits the maximum value of dc-link voltage、Furthermore, the output voltages and currents from the VSI can contain high harmonic