当前位置:文档之家› 变电站设计文献综述 毕业设计(学术参考)

变电站设计文献综述 毕业设计(学术参考)

文献综述摘要:随着工业时代的不断发展,人们对电力供应的要求越来越高,特别是供电的稳固性、可靠性和持续性。

变电站是电力系统的重要组成部分,它直接影响整个电力系统的安全与经济运行,电网的稳固性、可靠性和持续性往往取决于变电站的合理设计和配置。

降压变电所正朝着高效、模块、组合、通用、经济方向发展。

关键字:发展变电站高效稳定重要作用本课题来源及研究的目的和意义我国的变电站发展,至今为止,大约可以分为二个阶段:第一个阶段80年代末,我国的电网相当薄弱,南北电网处于分割状态,供需矛盾非常突出,随时都会拉闸限电;第二阶段,90年代中期,随着综合自动化变电站的建立,从35KV 变电所到110KV甚至500KV的综合自动化变电站建立投用,我国的电力事业发生明显变化。

近年来,电网日益坚强,科技不断进步,变电站有着飞速的发展,变电站实现集控化已成为变电站的一种发展趋势。

近年来,各国均对变电站的设计及使用技术进行了深入的研究,并取得了卓越的理论成就,离高效稳定节能的标准逐渐缩小距离。

现在是跨世纪的时代,科技的发展使变电站设备的科技含量也越来越高,新型的、多功能的变电站设备也相继出现。

如沈阳昊诚ZB-F系列箱式变,体积仅为国产常规箱式变的1/3~1/5;安全性高,产品无裸露带电部分,为全封闭、全绝缘结构,完全能达到零触电事故;防渗漏、防腐蚀。

河北电力设备厂生产的10~110kV箱式变,设有“四遥”可无人值守。

VFI(Vacuum Fault Interrupter Transformer)美式箱式变也以其独到的优势挤身于中国市场,如:最大容量可达10000kVA,可用手动或电动操作,并进而与SCADA系统结合,使技术逐步升级。

此外,近年来, 计算机技术和电子信息技术在电力建设中的应用越来越广泛, 变电站自动化技术也已经达到一定的水平, 随着智能化开关、光电式电流电压互感器、一次运行设备在线状态检测、变电站运行操作培训仿真等技术日趋成熟,以及计算机高速网络在实时系统中的开发应用, 势必对已有的变电站自动化技术产生深刻的影响, 全数字化的变电站自动化系统也即将出现。

电力工业是国民经济发展中最重要的基础能源产业,是国民经济的第一基础产业,是关系国计民生的基础产业,是世界各国经济发展战略中的优先发展重点。

作为一种先进的生产力和基础产业,电力行业对促进国民经济的发展和社会进步起到重要作用。

与社会经济和社会发展有着十分密切的关系,它不仅是关系国家经济安全的战略大问题,而且与人们的日常生活、社会稳定密切相关。

随着我国经济的发展,对电的需求量不断扩大,电力销售市场的扩大又刺激了整个电力生产的发展。

随着科学技术的发展和能源经济利用的需要,变电站的设计在逐步向经济、稳定的方向发展。

迄今为止,变电所的更新设计在国内外也正在逐渐形成一个与人类生活密不可分的行业。

优良更新的设计不仅具有标准化、高效化、组合化等当代先进设计思想,又符合节约有效利用资源的原则,更适合当代社会发展的要求。

所以是今后电力技术的一个重要发展方向。

变电站的发展现状变电站自动化技术经过10 多年的发展已经达到了一定的水平, 在我国城乡电网改造与建设中不仅中低压变电站采用了自动化技术, 实现无人值班, 而且在220kV 及以上的超高压变电站建设中也大量采用综合自动化新技术, 从而提高了电网建设的现代化水平, 增强了输配电的可能性, 降低了变电站建设的总造价。

随着智能化开关、光电式电流电压互感器、一次运行设备在线状态检测、变电站运行操作培训仿真等技术日趋成熟以及计算机高速网络在实时系统中的开发应用, 势必对已有的变电站自动化技术产生深刻的影响, 全数字化变电站自动化系统即将出现。

数字化变电站自动化系统发展中的主要问题:数字化变电站自动化系统的研究目前处于基础阶段, 主要集中在过程层方面, 诸如智能化开关设备、光电互感器、状态检测等技术与设备的研究开发。

目前存在的主要问题是: ①研究开发过程中专业协作需要加强, 比如智能化电器的研究至少存在机、电、光三个专业协同攻关。

②材料器件方面的缺陷及改进。

③试验设备、测试方法、检验标准, 特别是EMC (电磁干扰与兼容) 控制与试验还是薄弱环节。

我国电力工业自动化水平正在逐年提高。

20 MW及以上大型机组以采用计算机监控系统,许多变电所以装设微机综合自动化系统,有些已实现无人值班,电力系统已实现调度自动化。

迄今,我国电力工业已进入了大机组,大电厂,大电力系统,高电压和高自动化的新阶段。

我国在城乡电网改造与建设中不仅中低压变电站采用了自动化技术实现无人值班,而且在220kV及以上的超高压变电站建设中也大量采用自动化新技术,从而大大提高了电网建设的现代化水平,增强了输配电和电网调度的可能性,降低了变电站建设的总造价,这已经成为不争的事实,也是目前变电站建设的主要模式. 综合自动化的系统性要求极强,特别是结合了全站的操作防误系统,要求变电站建设一期工程越齐越好,而这在高电压等级的变电站建设中几乎是不可能的;扩建工程的操作防误闭锁逻辑实际验证困难,特别是牵涉到母线类的;一次设备电动操作全部受控于监控系统.监控系统的误动出口必须绝对禁止,对IO设备的运行可靠性要求很高;这是目前国内外在变电所设计中所面临的问题与挑战。

变电所综合自动化已成为当前变电所设计应用中的热门课题和发展的必然趋势。

在一些工业发达国家中,配电自动化系统受到了广泛的重视,国外的配电自动化系统已经形成了集变电所自动化、馈线分段开关测控、电容器组调节控制、用户负荷控制和远方抄表等系统于一体的配电网管理系统(DMS),其功能已多达140余种。

从国外配电自动化系统采用的通信方式看,尚没有一种通信技术可以很好地满足于配电系统自动化所有层次的需要。

在一个配电自动化系统内,往往由多种通信技术组合成综合的通信系统,各个层次按实际需要采用合适的通信方式。

研究内容变电站设计主要根据用电的要求电压等级来选择合理的变压器和母线的设置,来实现变换电压、接受和分配电能、控制电力的流向和调整电压的电力设施,通过变压器将各级电压的电网联系起来。

主要解决的问题有:1、变压器的选择2、母线的选择3、短路电流的计算4、继电保护装置的选择5、隔离开关、断路器的选择6、避雷装置的选择7、输电线的选择 8、电流电压互感器的选型 9、一次接线图、二次接线图的绘制对专变电站设计,可以了解变电所在变换和分配电能中的作用:可靠地保证整个电力系统的安全运行与经济效率,通过变电站的合理设计和配置充分发挥电网的稳固性、可靠性和持续性。

随着社会的发展,科技的不断提高,众多技术逐渐渗透到各个行业,如何利用这些高科技为人类服务,如何充分利用这些高科技在电气行业中,使之更好的为我们服务,这还需要电气行业人员不断的努力,开拓创新。

参考文献:[1]熊信银.《发电厂电气部分》.水利电力出版社,1992年[2]何仰赞等.《电力系统分析》.华中理工大学电力出版社,1991年[3]贺家李等.《电力系统及电保护原理》.水利电力出版社,1992年[4]吴广宁.《高电压技术》.浙江大学出版社,1994年[5]雍静.《供配电技术》.机械出版社,1994年[6]张冠生.《电器理论基础》.机械工业出版社,1991年[7]杨有启.《电气安全规程》.北京出版社,1991年[8]刘从爱.《电力工程》.机械工业出版社,1992年[9]王崇林、邹有明主编.《供电技术》.煤炭工业出版社,1996年[10]李军年.《电力系统继电保护》.水利电力出版社,1991年[11]国家标准GB50059-1992.《35-110kV变电所设计规范》.中国标准出版社,1992年[12]赵成军,解玉龙.电力系统继电保护方向性分析[J].科技资讯.2011(23)[13]薄艳云,王鹏,薄艳平.35KV变电站综自改造中常见问题改造对策及综自系统运行维护中常见问题[J].中国新通信.2013(05)[14]张宝归.35KV变电站的接地系统设计与施工问题研究[J].低碳世界.2013(12)[15]张华,郝建奇.35kV变电站防雷与接地分析[J].中国电业(技术版).2013(04)外文文献General Requirements to Construction of SubstationSubstations are a vital element in a power supply system of industrial enterprises.They 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 for110-220/6-10-35kV;deep entrance substations for 110-330/6-10Kv;distribution substations for 6-10Kv;shop transformer substations for 6-10/0.38-0.66kV.At the main step-down substations, the energy received from the power source is transformed from 110-220kV usually to 6-10kV(sometimes 35kV) which is distributed among substations of the enterprise and is fed to high-voltage 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 110-220kV 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.Step-up transformer substations are used at power plants for transformation of energy produced by the generators to a higher voltage which decreases losses at a long-distance 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 6-10kV are fed primarily from main distribution substations (sometimes from central distribution substations).With a system ofdividing substations for 110-220kV, the functions of a switch-gear are accomplished by switch-gears for 6-10kV 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 35-220kV 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 pre-made 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 two-bus systemsonly 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.e 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 switch-gear 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 movethrough 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 free-roving 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. V olta,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.MagnetsAlmost everyone has seen horseshoe magnets-so 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 aboutmagnets 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 ter, 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 wires-that 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.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。

相关主题