电气工程及其自动化专业英语.doc

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 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 informatio