电力专业英语

南京工程学院期末考查报告书成绩电气工程专业外语B 院（系、部、中心） 电力工程学院 专 业 电气工程及其自动化 班 级 电气071 学 生 姓 名 褚楚 学 号 206070819 任 课 教 师 朱建忠 2010年 7月 南 京 考查要求：1、 对已学的课程内容进行总结, 节选4篇课题作为报告的主题。2、 通过文献的搜索（可借鉴Google、Yahoo和电子图书馆的外文期刊），查找数篇与课程相关的资料（一定是经过选择后的文献，要最好的）。3、 通过已经掌握的专业词汇和课题背景对已查找的文献进行精心分析，分析角度可从词汇、语法和课题背景等。4、 对文献进行通篇翻译，翻译最好可直译，遇拗口的语句可选择意译。5、 翻译后从文中选出关键字。6、 总结翻译成果，写下中心思想。7、 考查报告总结（语句需简洁）。Page1. The Production of Electrical Energy(电能生产)1.English testFrom reference 1In large steam power plants, the thermal energy stored in steam is converted into work by means of turbines. A turbine consists essentially of a shaft or rotor fixed in bearings and enclosed in a cylindrical casing. The rotor is made to turn smoothly by means of jets of steam from nozzles around the periphery of the turbine cylinder. These steam jets strike blades attached to the shaft. Central power stations employ condensing turbines in which the steam passes into a condenser after leaving the turbine. Condensation is effected by the circulation of large quantities of cold water through the tubes of the condenser, thus increasing the expansion ratio of the steam and the consequent efficiency and work output of the turbine. the turbines are connected directly to large electricity generators.In turbines the action of the steam is kinetic. There is progressive expansion of the steam from the high pressure and relatively small volume at which it enters the turbine to the low pressure and relatively very great volume at which it leaves.Steam is made by heating water in a boiler. The usual boiler has a furnace in which fuel is burned and the heat given off during combustion is conducted through the metal walls of the boiler to generate steam at a pressure within the boiler vessel .In nuclear plants, steam is generated with the aid of a reator in which the controlled fission of uranium or plutonium supplies the necessary heat for the vaporization of water. Thus the reator replaces the steam generator of conventional plants.Keywords：turbine, steamFrom reference 2Up until now we have been mainly concerned with minimizing the cost of operating a power system. An overriding factor in the operation of a power system is the desire to maintain system security. System security involves practices designed to keep the system operating when components fail. For example, a generating until may have to be taken off-line because of auxiliary equipment failure. By maintaining proper amounts of spinning reserve, the remaining units on the system can make up the deficit without too low a frequency drop or need to shed any load. Similarly, a transmission line may be damaged by a storm and taken out by automatic relaying. If in committing and dispatching generation proper regard for transmission flows is maintained, the remaining transmission lines can take the increased loading and still remain within limit. Because the specific times at which initiating events that cause components to fail are unpredictable the system must be operated at all times in such a way that the system will not be left in dangerous condition should any credible initiating event occur. Since power system equipment is designed to be operated within certain limits, most pieces of equipment are protected by automatic devices that can cause equipment to be switched out of the system if these limits are violated. If any event occurs on a system that leaves it operating with limits violated, the event may be followed by a series of further actions that switch other equipment out of service. This is usually referred to as a system blackout.Keywords：power system, securityFrom reference 3System monitoring provides the operators of the power system with pertinent up-to-date information on the conditions on the power system .Generally speaking it is the most important function of the three. From the time that utilities went beyond systems of one unit supplying a group of loads, effective operation of the system required that critical quantities be measured and the values of the measurements be transmitted to a central location. Such systems of measurement and data transmission, called telemetry systems, have evolved to schemes that can monitor voltages, currents, power flows, and the status of circuit breakers switches in every substation in a power system transmission network. In addition, other critical information such as frequency, generator unit outputs and transformer tap positions can also be telemetered. With so much information telemetered simultaneously, no human operator could hope to check all of it in a reasonable time frame. For this reason, digital computers are usually installed in operations control centers to gather the telemetered data, process them, and place them in a data base from which operators can display information on large display monitors. More importantly, the computer can check incoming information against prestored limits and alarm the operators in the event of an overload or out-of-limit voltage. State estimation is often used in such systems to combine telemetered system data with system models to produce the best estimate (in a statistical)of the current power system conditions or “state”.Keywords：telemeter, estimateFrom reference 4The main objective of production control in power system is to minimize the cost of generated power while maintaining its quality and satisfying the system security constraints. This implies directly that losses in both the generation and the transmission of electrical energy must be as small as possible. All participating generators are run at high efficiencies, the mix of production resources is exploited economically and the energy is transmitted optimally. Production control includes general both active and reactive power. However, the main interest in this type of application has so far been focused mainly on the active part. This is the case in this section also. However, interest for the reactive part is rapidly growing and will soon get a great deal of action. The activities in the production control field have traditionally been based on planning. This is still the case. The aim is then to break down the overall objective into detailed plans, normally on an hourly basis, that can be carried out by the operator in the control center. Thus, several steps are taken in a hierarchical scheme to support the operators ambition always to have production resources available to meet the load demand and guide him to operate the generating units so that the most economic alternatives are chosen. The security aspects must also be consisted ,e.g. the selection of production units must not result in line overloads, too high bus voltage etc. If the system suffers the sudden loss of generation, it must be prevented from getting into the alert state for example by activating production reserves. Keywords：production control, security2中文翻译及分析出自文献1： 在大型火电厂中，蒸汽中储存的热能通过汽轮机做功。汽轮机基本上是由轴或者固定在轴承之间封闭在圆柱形汽缸内的转自组成。转子由汽轮机汽缸周围的喷嘴喷出的气流推动而平稳转动。这些喷射蒸汽流冲击安装在轴上的叶轮。中心发电厂应用凝汽式汽轮机，使蒸汽离开汽轮机进入凝汽器，由凝汽器管束内的大量循环冷却水进行凝汽，这样就增加了蒸汽的膨胀率和效益，也增加了汽轮机的输出。汽轮机直接连接大型的发电机组。 在汽轮机内，蒸汽是运动的，它有一个逐渐膨胀的过程：进入汽轮机时，蒸汽在高压下有相对较小的体积，而离开汽轮机时，在低压下有相对较大的体积。 蒸汽由锅炉内的热水生成。一般锅炉有燃烧室，燃料在燃烧室燃烧，燃烧过程中散发的热通过锅炉内的金属壁传导，在锅炉内产生一定压力下的蒸汽。在核电厂，借助反应堆内铀或钚的裂变提供的热量来使水汽化产生蒸汽。这样，反应堆就取代了传统电厂的蒸汽发生器。关键字：汽轮机，蒸汽出自文献2：到目前为止，我们一直主要关心最大限度德降低电力系统的运行成本，电力系统运行中最重要的就是维护系统的安全。系统安全之际上涉及涉及：当系统中部分设备发生故障时，系统还能正常运行。例如，一套发电机组因为附属设备发生故障而不得不停止工作。通过维持适量备用发电能力，系统内仍在工作的发电机组可以弥补发电量的不足而不会使频率下降太多，也不需要拉闸断电。同样，一条输电线可能遭受暴风雨而受损，自动中续保护器则会使其与电网断开，如在发电调度时，保持对输电线路的适度关注，其余的输电线路就会承担相应的负荷，而电力系统仍处于安全。因为使电力系统的设备发生故障的始发事件的特定时间不可预测，电力系统必须一直以下列方式运行：任何可信始发事件发生时，电力系统都不会处于危险状态。由于电力系统的设备设计成在一定的限度内工作，大多数设备在超出限度时，自动保护装置会使设备与系统断开而保护设备。假设系统内任何事件使系统超限运行，随后会产生一系列的反应，使其他设备停止工作。如果这一过程继续，整个电力系统或系统大部分可能完全瘫痪。这通常被称为电力系统断电。关键字：电力系统，安全出自文献3： 系统控制功能为电力系统操作人员提供与电力系统相关的最新状态信息。一般而言，它是三个功能中最重要的功能。从电力公司超越一台机组系统系统供应一组负荷之时起，电力系统有效的运行要求测量最重要的数据，并把侧到的数据传送到控制中心。这样的测量和数据传送的遥测系统已经发展成为可以监控电压、电流、电能流和电力系统输电网络内每一变电站的线路断路器和开关状态的装置。此外，其他重要性信息，如频率、发电机组输出和变压器抽头位置也可以遥测。这么多数据同时遥测，操作人员不可能在合理的时间内全部核实。因此，通常在运行控制中心安装数字计算机来收集、分析遥测数据并把数据存入数据库。操作人员也可以把信息从数据库调出并显示在大屏幕上。更重要的是，计算机可以把输入数据与之前存储的限制数据进行对比，并在过载或超限电压时向操作人员发出警示。 这样的系统长应用状态把遥测系统数据与系统模型相结合，作出现在电力系统状态最佳的评估（统计学意义上的）。关键字：遥测，评估出自文献4：电力系统内生产控制的主要目标是：在维持电能质量和满足系统安全要求的条件下，最大限度地降低生产电能的成本。这意味着生产和输送电能的损耗必须尽可能小。所有参与的发电机组将高效运转，并以混合方式经济地开发利用生产资源和优化输送电能。生产控制一般包括有功功率和无功功率。到目前为止，对这种应用的主要兴趣仍主要集中在有效功率上，这一节的内容也是如此。但对无功功率的兴趣在快速增长，并将极大地重视。生产控制领域的活动传统上是根据计划进行的。现在仍旧如此，目的是把整个计划分解成比较详细的子计划，一般以小时为基本单位。控制中心的操作人员可以执行这种子计划。因此可以在分级计划内采取若干步骤来支持操作人员的愿望：总有生产资源可以利用来满足负荷需要并指导他们以最经济方式路过负荷、过电压等。假设系统突然失去一些发电能力，必须启动备用发电机组以防止进入警戒状态。关键字：生产控制，安全3 长难句分析及专业词汇a). continuity n. 连续性b). bearing n. 轴承c). kinetic a. 运动的d). vaporization n. 蒸汽，汽化e). pelton wheel n. 冲击式水轮机4 中心思想三相系统是目前最常用的发电和输电系统。目前发电的主要方式是火力发电，水力发电，核电等，其中火力发电应用最广泛。电力系统运行时，应使任何始发事件发生时，电力系统都不会处于危险状态。系统的控制功能是电力系统最重要的功能，运行中常将采集到的系统数据与系统模型相结合，以此来评估系统的运行状态。5 列出文献1.王宏文等.自动化专业英语教程.北京：机械工业出版社，19982.冯俊宝.电力专业英语基础.北京：中国电力出版社，20093.冯俊宝等.电力专业英语基础学习指南.北京：中国电力出版社，20084.刘然等.电力专业英语（第三版）.北京：中国电力出版社，2010Page2. Generators and Motors(发电机和电动机)1.English testFrom reference 1 The basic electrical principle underlying operation of dc generators is called “generator action”. If a length of wire is moved thorough a magnetic field in such a way that the wire cuts between the North and South poles producing the magnetic field, an electric voltage will be set up in the wire. of course, the voltage set up in a single length of wire would be small. But if a large number of wires were connected end to end and rotated in the magnetic field, the voltage set up in the series of the wire lengths would be equal to the sun of voltages set up in the individual lengths wire. “Generator action” is the effect whereby the voltage is set up in a moving conductor. In dc generators, the conductors are wound into coils and mounted in slots on the armature or rotating element within the units housing. The end of each coil of conductors are brought out to one end of the armature where they are connected to individual insulated bars in a assembly of such bars, which is mounted around the armature shaft. This assembly is called the “commutator”, which is required to provided direct-current output from the generator. The wires that come out of the generator, one for the positive side of the dc output and one for the negative side, are connected within the generator to carbon brushes which ride on the commutator. The brushes pick up the electric current from the commutator and pass it to the circuit being fed by the generator. Keywords：generator, voltageFrom reference 2An electric motor can be reserved by reserving the direction of the current in either its armature or its field coils. If both currents are reserved the motor continues to turn in the same direction, and it follows that the commutator motors described above will work from an AC supply. There are, however, two special kinds of motor that can be used with AC only. The first of these is called a synchronous motor because it synchronizes itself, that is, it keeps in step with the AC supply. The moving part, called the rotor, is a straight bar magnet mounted on a spindle thorough its center between the poles of an electromagnet. When the electromagnet is joined to an AC supply its magnetism reserves regularly each time the current changes direction, and its poles become alternately N and S. The synchronous motor is not self-starting, but if the rotor is spun round by hand at the correct speed, its S pole is always approaching the upper pole of the electromagnet when this is a N pole. And by the same time electromagnet current has changed the upper pole to a S pole, the rotor has turned so that the N pole is approaching. The magnetic attraction between the opposite poles of the rotor and the electromagnet pulls the rotor round and keeps it moving. The current, synchronous, speed is when the rotor revolves once for each complete cycle of the AC supply, with a 50 cycle AC supply the synchronous motors speed is 50 revolutions per second, that is 3000 revolutions per minute. This kind of motor has a perfectly constant speed as long as the frequency of the AC supply stays constant, and because of this it is used to drive electric clocks. Keywords：electric motor, rotorFrom reference 3 Synchronous machines can be classified as cylindrical-rotor or salient-pole machines. The cylindrical-rotor construction is used in high steam-turbine-driven generators. The armature windings consist of laminated conductors placed in the sator slots. They are usually 3-phase Y-connected windings, and voltages of above 13,800 volts, line to line, are common in sizes above several thousand kilowatts. The rotor carries the dc field windings. Most of the turbine generators being built at present for 60-cps service are 2-pole 3,600-rpm machines. Because of the economics of high-speed high-temperature high-pressure steam turbines, much study and some real pioneering work have been devoted to improvements in materials and design of both generators and turbines, and the maximum ratings for which 3,600-rpm machines have been built have approximately doubled during the decade. The advantage of large units are: somewhat increased efficiency, somewhat lower capital cost per kilowatt, and the lower plant operating cost because of the greater ease of operating a generating station consisting of a relatively few large units as compared with one consisting of many smaller units. Keywords：Synchronous machine, sizeFrom reference 4 Because of the high rotational stresses, the rotors of turbine generators must be designed for as small a diameter as is consistent with other requirements. At the same time, limitations are imposed on the axial length of the rotor by vibration considerations. Hence the design of the rotor is indeed a difficult problem, and the design of the whole machine is largely determined by it. Stresses are high, operating temperatures are high, and space is cramped. The insulation is subjected to severe rotational stresses, relatively high temperatures, and severe stresses caused by thermal expansion of the coils. These factors make a low-voltage rotor winding desirable. Turbine generators usually are designed for excitation at voltage of 125 to 375 volts. The field current usually is obtained from an exciter coupled to the shaft of the generator. The air gaps of turbine generators usually are much longer than in other types of machines. A long air gap reduces the reactance of the armature wingding and improves voltages regulation and stability. It is also necessary for ventilation. An obvious advantage of a long air gap is that it necessitates a greater field mmf to produce a specified air-gap flux. The cooling problem in electrical apparatus in general increases in difficulty with increasing size, because the surface area from which the heat must be carried away increases roughly as the square of the dimensions, while the heat developed by the losses is roughly proportional to the volume and therefore increases approximately as the cube of the dimensions. Because of their compactness, this problem is a serious one with large turbine generators.Keywords：turbine generator, design1. 中文翻译及分析 出自文献1： 构成直流发电机运行基础的基本电气原理被称作“发电机行为”。如果一段导线以切割产生的磁场的N极和S极的磁力线方式通过这个磁场，那么这段导线中就会产生电压。当然，在单独的一段导线中产生的电压是很小的。但是，如果大量的导线首尾相连并在磁场中旋转，那么在这一系列导线中产生的电压将等于在单个导线中产生的电压的和。“发电机行为”可以解释为何电压会在移动导线中产生。 在直流发电机中，导线缠绕成线圈，并安在电枢线槽内或电机壳内的旋转部件上。每个线圈导线的末端连接到电枢一端的单独绝缘的母线上；这些母线构成的汇流排安装在电枢轴上。这个装置叫“换向极”，用来为发电机提供直流输出。这些从发电机出来的导线，一条用作直流电输出的正极，另一条用作负极，它们在发电机内连接到换向器的电刷上。这些电刷从换向器获取电流，并将其传送到发电机供给的电路中去。关键字：发电机，电压出自文献2 通过改变电枢或励磁线圈的电流方向，电动机会逆向转动。如果两边电流同时逆转，那么发电机仍会向同一个方向转动，因此得出，交流电将驱动上文所描述的整流式电动机旋转。但是，有两种特别的电动机只能用交流电作为电源。第一种是同步电动机，因为它使自身同步，也就是说，它和交流电保持同步。转动部分即转子，是直条形磁极，它安装在从电磁铁磁极中心穿过的主轴上。当电磁铁连接到交流电时，它的磁场方向随电流方向改变而逆转，其磁极交替变成N和S极。同步电动机不是自启动的，但如果转子以合适的速度用手旋转，当它S极总是接近电磁铁的上部磁极时，这是N极。当电磁铁电流改变，使得上边的磁极转向S极时，转子也改变，所以N极在靠近。转子和电磁铁直接相反的两级之间的磁吸力拉动转子旋转，并使它保持运动。合适的转速（同步转速）使转子在交流电一个周期，完成完整的一圈旋转。交流电的频率是50Hz，那么同步电动机的速度就是50次每秒，也就是3000转每分钟。只要交流电供应保持频率恒定，此类型的电动机速率也就恒定，所以常用来驱动电子时钟。关键字：电动机，转子出自文献3同步电机可分为圆柱式转子电机和凸极电机。圆柱式转子结构用于高速汽轮发电机中。其电枢绕组由置于定子槽内的分层导体组成，一般为三相Y连接的绕组，而13800V以上的线电压通常用于数千千瓦以上的容量。转子装有直流励磁绕组，目前制造的用于60Hz的大多数汽轮发电机具有2极3600r/min的电机。由于高速高温高压汽轮机的经济性，已进行了许多研究和具有开拓性的工作以改进发电机和汽轮机的材料和设计。而近十年，3600r/min的电机的最大容量已接近翻一番。大型设备的优点是：效率有所增加，每千瓦的投资费用有所减小，同时设备运行费用降低。这是因为由相对较少的大容量机组组成的发电站运行起来比由较多容量机组组成的电站要简单。关键字：同步电机，容量出自文献4：由于旋转应力高，汽轮发电机的转子直径在满足其他要求时应尽量设计得小一些。同时从震动考虑，转子的轴向长度受到限制。因此转子的设计实在是一件困难的事，而整个电机的设计基本上受它限制，困难表现在应力高，运行温度高及空间限制严格。绝缘承受严重的旋转应力、较高的温度以及线圈膨胀而引起的严重应力。这些因素使它希望低压的转子绕组。汽轮发电机的励磁电压通常设计成125-375V。励磁电流一般从与发电机共轴连接的励磁机中获得。汽轮发电机的空气气隙通用比其他类型的电机的大得多。大的空气气隙会减小电枢绕组电抗，因而改善电压的调整率和稳定度。大的气隙也是通风的需要。大气隙的一个显著的缺点是，它需要较大励磁磁动势以产生规定的气隙磁通。通常，随着容量的增加电气装置的冷却苦难也增加，这是因为散热表面大约按尺寸的平方增加，而损耗产生的冷却大约正比于体积，因此近似地按尺寸的平方增加。由于尺寸紧缩，所以这对大型发电机来说是一个严重的问题。关键字：汽轮发电机，设计3 长难句分析及专业词汇a).rotate v.旋转b).excitation n.励磁c).revolution n.旋转一周d).in parallel 并联e).flux n.磁通f).polyphase a.多相的4 中心思想发电机分为交流发电机和直流发电机，分别将机械能转化为交流电能与直流电能。汽轮发电机的转子设计很困难，而整个电机的设计受其限制，在各种因素下转子直径应尽量设计得小一些。同步电动机交流电保持同步，速率恒定，所以常用来驱动电子时钟。5 列出文献1.王宏文等.自动化专业英语教程.北京：机械工业出版社，19982.冯俊宝.电力专业英语基础.北京：中国电力出版社，20093.冯俊宝等.电力专业英语基础学习指南.北京：中国电力出版社，20084.刘然等.电力专业英语（第三版）.北京：中国电力出版社，2010Page3. Electrical Energy Transmission（电能输送）1.English testFrom reference 1 When lightning makes a direct hit on a transmission line, it deposits a large electric change, producing an enormous overvoltage between the line and ground. The dielectric strength of air is immediately exceeded and a flashover occurs. The line diachanges itself and overvoltage disappears in typically less than 50us. Unfortunately, the act between the line and ground(initiated by the lightning stroke)produces a highly ionized path which behaves like a conducing short-circuit. Consequently, the normal AC line voltage immediately delivers a large AC current that follows the ionized path. This follow-through current may sustain the arc until the circuit breakers open at the end of the line. The fastest circuit breakers will trip in 1/15th of a second, which is almost 1000times longer than the lightning stroke itself. Direct hits on a transmission line are rare; more often, lightning will strike the overhead ground wire that shields the line. In a latter case, a local charge still accumulates on the line, producing a very high local overvoltage. This concentrated charge immediately divides into two ways that swiftly move in opposite directions at close to the speed of light (300m/us). The height of the impulse wave represents the magnitude of the surge voltage that exists from point to point between the line and ground. The peak voltage(corresponding to the crest of the wave)may attain one or two million volts. Wave front is concentrated over a distance of about 300m, while tail may stretch out over several kilometers.Keywords：lightning， transmission lineFrom reference 2 Should the wave encounter a line insulator, the latter will be briefly subjected to a violent overvoltage. The over-voltage period is equal to the time it takes for the wave to sweep past the insulator. The voltage rises from its nominal value to several hundred kilovolts in about 1us, corresponding to the length of wavefront. If the insulator cannot withstand this overvoltage, it will flash over, and the resulting follow-through current will cause the circuit breakers to trip. On the other hand, if the insulator does not fail, the wave will continue to travel along the line until it eventually encounters a substation. It is here that the impulse wave can produce real havoc. The windings of transformers, syn