变电站设计外文翻译毕业设计.doc

变电站设计外文翻译毕业设计外文文献一General Requirements to Construction of SubstationSubstations are a vital element in a power supply system of industrial enterprisesThey serve to receive ，convert and distribute electric energy 。Depending on power and purpose ，the substations are divided into central distribution substations for a voltage of 110-500kV;main step-down substations for110-220/61035kV；deep entrance substations for 110330/6-10Kv；distribution substations for 610Kv;shop transformer substations for 610/0.38-0.66kV.At the main stepdown substations， the energy received from the power source is transformed from 110220kV usually to 6-10kV(sometimes 35kV） which is distributed among substations of the enterprise and is fed to highvoltage services.Central distribution substations receive energy from power systems and distribute it (without or with partial transformation） via aerial and cable lines of deep entrances at a voltage of 110220kV over the enterprise territory .Central distribution substation differs from the main distribution substation in a higher power and in that bulk of its power is at a voltage of 110-220kV;it features simplified switching circuits at primary voltage; it is fed from the power to an individual object or region .Low-and medium-power shop substations transform energy from 6-10kV to a secondary voltage of 380/220 or 660/380.Stepup transformer substations are used at power plants for transformation of energy produced by the generators to a higher voltage which decreases losses at a longdistance transmission 。Converter substations are intended to convert AC to DC (sometimes vice versa) and to convert energy of one frequency to another 。Converter substations with semiconductor rectifiers are convert energy of one frequency to another 。Converter substations with semiconductor rectifiers are most economic。 Distribution substations for 610kV are fed primarily from main distribution substations (sometimes from central distribution substations）。With a system of dividing substations for 110-220kV, the functions of a switch-gear are accomplished by switchgears for 610kV at deep entrance substations。Depending on location of substations their switch-gear may be outdoor or indoor。 The feed and output lines at 6-10kV substations are mainly of the cable type 。at 35220kV substations of the aerial type 。When erecting and wiring the substations ，major attention is given to reliable and economic power supply of a given production。Substations are erected by industrial methods with the use of large blocks and assemblies prepared at the site shops of electric engineering organizations and factories of electrical engineering industry 。Substations are usually designed for operation without continuous attendance of the duty personnel but with the use of elementary automatic and signaling devices.When constructing the structural part of a substation 。it is advisable to use light-weight industrial structures and elements （panels ,floors ,etc。） made of bent sections .These elements are premade outside the erection zone and are only assembled at site .This considerably cuts the terms and cost of construction。Basic circuitry concepts of substations are chosen when designing a powersupply system of the enterprise 。Substations feature primary voltage entrances 。transformers and output cable lines or current conductors of secondary voltage .Substations are mounted from equipment and elements described below .The number of possible combinations of equipment and elements is very great 。Whenelaborating a substation circuitry ，it is necessary to strive for maximum simplification and minimizing the number of switching devices .Such substations are more reliable and economic .Circuitry is simplified by using automatic reclosure or automatic change over to reserve facility which allows rapid and faultless redundancy of individual elements and using equipment。When designing transformer substations of industrial enterprises for all voltages , the following basic considerations are taken into account：1. Preferable employment of a single-bus system with using twobus systems only to ensure a reliable and economic power supply；2。 Wide use of unitized constructions and busless substations；3.Substantiated employment of automatics and telemetry ;if the substation design does not envisage the use of automatics or telemetry ，the circuitry is so arranged as to allow for adding such equipment in future without excessive investments and re-work.4.Use of simple and cheap devices-isolating switches ，short-circuiting switches ,load-breaking isolators ，fuses ，with due regard for their switching capacity may drastically cut the need for expensive and critical oil ，vacuum ，solenoid and air switches .Substation and switchgear circuitries are so made that using the equipment of each production line is fed from individual transformers ，assemblies ,the lines to allow their disconnection simultaneously with mechanisms without disrupting operation of adjacent production flows.When elaborating circuitry of a substation， the most vital task is to properly choose and arrange switching devices（switches ，isolators ，current limiters ，arresters ，high-voltage fuses）.The decision depends on the purpose ，power and significance of the substation.Many years ago, scientists had very vague ideas about electricity. Many of them thought of it as a sort of fluid that flowed through wires as water flows through pipes， but they could not understand what made it flow。 Many of them felt that electricity was made up of tiny particles of some kind ，but trying to separate electricity into individual particles baffled them.Then, the great American scientist Millikan, in 1909,astounded the scientific world by actually weighing a single particle of electricity and calculating its electric charge. This was probably one of the most delicate weighing jobs ever done by man，for a single electric particle weighs only about half of a millionth of a pound. To make up a pound it would take more of those particles than there are drops of water in the Atlantic Ocean.They are no strangers to us, these electric particles, for we know them as electrons。 When large numbers of electrons break away from their atoms and move through a wire，we describe this action by saying that electricity is flowing through the wire。Yes，the electrical fluid that early scientists talked about is nothing more than electrical flowing along a wire.But how can individual electrons be made to break away from atoms? And how can these free electrons be made to along a wire？ The answer to the first question lies in the structure of the atoms themselves. Some atoms are so constructed that they lose electrons easily。 An atom of copper, for example ,is continually losing an electron, regaining it(or another electron)，and losing it again. A copper atom normally has 29 electrons， arranged in four different orbits about its nucleus。 The inside orbit has 2 electrons。 The next larger orbit has 8.The third orbit is packed with 18 electrons . And the outside orbit has only one electron。It is this outside electron that the copper atom is continually losing, for it is not very closely tied to the atom。 It wanders off, is replaced by another freeroving electron， and then this second electron also wanders away。 Consequently，in a copper wire free electrons are floating around in all directions among the copper atoms.Thus， even through the copper wire looks quite motionless to your ordinary eye, there is a great deal of activity going on inside it。 If the wire were carrying electricity to an electric light or to some other electrical device, the electrons would not be moving around at random. Instead, many of them would be rushing in the same direction-from one end of the wire to the other。This brings us to the second question .How can free electrons be made to move along a wire？ Well ,men have found several ways to do that 。One way is chemical. Volta,s voltaic pile，or battery, is a chemical device that makes electricity（or electrons)flow in wires. Another way is magnetic. Faraday and Henry discovered how magnets could be used to make electricity flow in a wire.Magnets Almost everyone has seen horseshoe magnetsso called because they are shaped like horseshoes. Probably you have experimented with a magnet， and noticed how it will pick up tacks and nails, or other small iron objects. Men have known about magnets for thousands of years。 Several thousand years ago， according to legend, a shepherd named Magnes lived on the island of Crete, in the Mediterranean Sea .He had a shepherds crook tipped with iron. One day he found an oddly shaped black stone that stuck to this iron tip.Later, when many other such stones were found， they were called magnets（after Magnets).These were natural magnets. In recent times men have learned how to make magnets out of iron。 More important still， they have discovered how to use magnets to push electrons through wiresthat is， how to make electricity flow。 Before we discuss this, there arecertain characteristics of magnets that we should know about.If a piece of glass is laid on top of a horse- shoes magnet, and if iron filings are then sprink ledon the glass， the filings will arrange themselves into lines。 If this same thing is trid with a bar magnet（a horseshoe magnet straightened out）,the lines can be seen more easily. These experiments demonstrate what scientists call magnetic lines of force. Magnets, they explain， work through lines of force that ext end between the two ends of the magnet. But electrons seem to have magnetic lines of force around them， too.This can be proved by sticking a wire through a piece ofcard board， sprinkling iron filings on the cardboard， and connecting a battery to the wire. The filings will tend to form rings around the wire,as a result of the magnetism of the moving electrons（or electricity）。So we can see that there is arelationship between moving electrons and magnetism, Magnetism results from the movement of electrons. Of course， electrons are not really flowing in the bar magnet， but they are in motion, circling the nuclei of the iron atoms. However， in the magnet， circling thelined up in such a way that their electrons are circling in the same direction. Perhaps a good comparison might be a great number of boys whirling balls onstrings in a clockwise direction around their heads.翻译：变电站建设的一般要求变电站(所）在电源系统的工业企业是一个至关重要的因素。他们接收，转换和发送电能。根据能源和需求，变电站分为中央配电变电站电压为110500kV；主要降压变电所电压为110220/6-1035kV； 深入口变电站为110330/610kV；二次变电站的电压为610Kv；车间变电所电压为610/0。38-0.66kV。在主要的降压变电所，电源能量转化电压为110220kV,通常使用6-10Kv(有时为35kV变电所）的电压分配给企业和被用来满足高压服务。中央配电变电站从电力系统接收能量并分发它(不包括或者包括部分变换） 给企业不同区域，通过空中电缆和地下电缆线路电压为110-220kV。 中央分配变电站站不同于主配电变电它是一个更强大的电力设施,它的电压大部分在110220kV的电压。它可以简化初级电压、中级电压或地区的开关电路。中低级别变电站改造能量来自610kv的电压,它的二次侧电压为380/220或660/380。升压变压器变电站用于将电厂产生的能量转化使发电机产生的电压升高，从而有效地减少在远距离输电能量的损失转换器变电站的目的是为了将直流转换成交流(有时相反)和转换成能量时改变频率.转换器变电站的能量转换是用半导体整流器来变频的。带半导体整流器的转化器变电站是最经济的.6-10kV的配电变电站主要依据主配电变电站（有时依据中央配电变电站）.110-220kV变电站系统区域的划分时，根据变电站设备功能划分时是有学问的，610kV的变电站设备划分在变电站的入口。根据变电站变的位置，电站设备在可以露天或室内。610kV变电站的在电缆的类型主要是供给输出线。在35-220kV变电站空中线路样式，在变电站架线和接线，主要注重供电生产的可靠和经济。用工业的方式建设变电站，是使用大量的数块和在电气工程组织和工厂电气工程等行业的车间的位置进行组装.变电站通常是专为不连续操作的责任人员所设计，但用的是基本的自动设备和信号装置。当建立变电站结构的一部分,应当采用薄型建造结构以及由弯段组成的组件(板材、地板等)。这些元件是预先安装区外面建造区域并且只是在这个位置组装。这样可以有效的削减变电所建造成本。变电站基本电路概念设计的选择，是根据企业的供电系统特点得到的。变电站电压特性主要入口，变压器和输出电缆线路导线或当前导体的二次电压.变电站安装的设备和元件，设备和元件的若干种可能的组合是非常好的.当阐述了变电站的电路时争取切换装置最大的简化和数目的最小化。这样的变电站更可靠、经济。电路简化是采用自动接入或自动转入储备的方法,允许快速和无错误的自动接入每一个元件和使用设备.当设计工业企业全电压变电站时,下面的基本因素都要考虑在内。1.优先使用采用两编组的单总线系统可以确保可靠的和经济的供应电力。2。配套建设和变电站广泛使用.3。变电站使用自动化并且支持遥测技术；如果变电站的设计并不支持使用自动化或遥测、线路安而且不允许添加设备,确保以后没有过度投资和返工.4。使用简单、便宜的装置，有绝缘装置的断路器、短路开关、过载保护隔离器、保险丝，预期到他们的交换容量可考虑大幅度削减昂贵的器件需要和临界油、真空、螺线管和空气开关电路使用。变电站和开关电路，采用这样的设备的每个生产线服从个体变压器、装配、允许他们同时的断开而不破坏断开连接的生产流程的机制的线条。变电站的线路的意义,最重要的一点是要妥善安排与选择转换器件（开关、隔离者、电流限制器等、避雷器、高低压熔断器)，这决定了变电站的目的、功能和意义。很多年以前，科学家们对电仍只有很模糊的概念.他们之中不少人认为电是一种“流体"，这种流体就像水流经管道一样流过导线。但他们并不了解是什么东西使电流动.他们之中的许多人觉得电是有某种极小的微粒构成的，但试图把电分离成单个的小颗粒他们却束手无策。此后，以为伟大的美国科学家密利坎于1909年,真正地称出了单个的电粒子的重量并算出它的电荷而使科学界震惊不已。这可能是人类做过的最细致的计量工作之一，因为一个单个的电粒子的重量仅为一磅的百万分之一,百万分之一的一半左右的重量。要合成一磅重需要的电粒子数将要比大西洋的全部水的水滴数还要多。这些电粒子,他们对我们并不陌生，因为我们知道他们就是电子。当大量电子摆脱原子跑出来并通过导线运动时,我们把这种现象说成是电通过导线“流动”。是的,早先的科学家所说的电的“流体”只不过是沿着导线流动的电子。那么，如何能使一些单个的电子摆脱原子的束缚而跑出来呢？而且，又怎样能使这些自由电子沿导线运动呢？第一个问题的答案就在于原子本身的结构上。某些原子的结构使他们很容易失去电子。例如,一个铜原子在正常情况下有29个电子，它们排列在核子周围的4个不同的轨道上。最里层的轨道上有2个电子。第二层较大的轨道上有8个电子。第三层轨道上挤满18个电子。而外层轨道上只有一个电子。正是这个外层电子，铜原子不断丢掉它，因为这个电子受原子的约束不那么紧。它忽而游离而去，并被另一游离的电子所替代,然后,这后一个电子也游离而去.结果，在铜导线中自由电子在铜原子之间向四面八方漂浮。所以，尽管对你们的普通的肉眼来说，铜导线看来是完全不动的,但在它内部却不断地进行着大量的活动。如果导线把电输送到一盏电灯或者另外某个电气设备那里，这些电子就不会杂乱无章地到处跑来跑去,而是它们中的许多电子将会向一个方向奔去从导线的一端奔向另一端。这就把我们引向第二个问题，如何才能使自由电子沿导线运动呢？好啦，人们已经找到几种方法来做到这一点。一种就是化学方法。伏特电堆,或者叫电池，就是能使电流在导线中流动的一种化学装置。另一种方法就是电磁法。法拉第和亨利发现了怎样能把磁铁用来使电在导线中流动的办法。磁铁几乎每个人都见过马蹄形磁铁-之所以这样叫他是因为他们的形状做成马蹄形的。可能你们都用磁铁做过试验，并且看到它是怎样吸起按钉，小钉子或者其他一些小铁件的。人们了解磁铁已经几千年了。据传说，几千年前有个名叫麦格尼斯的牧羊人住在地中海的克里特岛上.他有一根牧羊人用的带铁头的棍杖。一天,他发现一块奇形怪状的黑石头黏在铁头上.后来,当又发现许多这种石头时，人们就叫它们为磁铁。这些就是天然磁铁。近年来，人们已经掌握怎样使用铁来制成磁铁。尤其重要的是，人们发现了如何使用磁铁推动电子通过导线也就是怎样使电流动。在我们讨论这点之前，磁铁有某些特性我们应当了解。如果把一块玻璃放在马蹄形磁铁的端部，然后把一些铁粉末撒在玻璃上,那么铁粉自己就会排成许多线。如果用一根棒做的话,就更容易看出这些铁粉排成的线条了.这些实验演示了科学家们所谓的磁力线。他们解释说。磁铁通过磁铁两端之间延伸出来的磁力线起作用.但是，在电子周围似乎也有磁力线。把一根导线穿过一块硬纸板，在纸板上撒上铁粉，并把电池与导线连通在一起，这点就可以得到证明.由于运动的电子的磁性的结果，铁粉就会绕导线周围形成一些圆环。因此，我们可以看到,在运动者的电子和磁性之间有一种关系。磁性就是由电子的运动引起的。当然,电子并不是在磁棒里真的“流动"，但它们却是在运动,在绕铁原子核做旋转运动。然而，在磁铁中，原子都排列的使它们的电子都向同一方向旋转。也许可打一个恰当的比喻，就像许多小孩在他们头顶上以顺时针方向甩动系在线上的小球一样。外文文献二With the development of science and technology, people in their daily lives is becoming more and more demand on the electrical and lighting, etc。 In addition to the general demand for electricity with the addition there are many closely related, so we have the stable operation of power systems have become increasingly demanding, variable by electric power system and as an important component of stability as it plays an equally important role. The vast majority of electricity consumers by power companies to supply the electric power system, a complete power system from the distribution around the different types of power plants, boost and stepdown substations， transmission lines and users. As everyone knows， the power of modern industrial production is the major source of energy and power. Power not only easy from other forms of energy conversion from, but also easy to convert to other forms of energy used to supply； electricity transmission and distribution is simple and economic， and easy to control, regulation and measurement, and conducive to the realization of the production process automation。The protection of the main current of the protection of the grid， the grid distance protection, differential protection of power networks， power grids of highfrequency protection， automatic reclosing, power transformer relay protection， power capacitor protection. With the development of relay