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1、文獻(xiàn)綜述摘要：隨著工業(yè)時(shí)代的不斷發(fā)展，人們對(duì)電力供應(yīng)的要求越來(lái)越高，特別是供電的穩(wěn)固性、可靠性和持續(xù)性。變電站是電力系統(tǒng)的重要組成部分，它直接影響整個(gè)電力系統(tǒng)的安全與經(jīng)濟(jì)運(yùn)行，電網(wǎng)的穩(wěn)固性、可靠性和持續(xù)性往往取決于變電站的合理設(shè)計(jì)和配置。降壓變電所正朝著高效、模塊、組合、通用、經(jīng)濟(jì)方向發(fā)展。 關(guān)鍵字：發(fā)展 變電站 高效 穩(wěn)定 重要作用本課題來(lái)源及研究的目的和意義 我國(guó)的變電站發(fā)展，至今為止，大約可以分為二個(gè)階段：第一個(gè)階段80年代末，我國(guó)的電網(wǎng)相當(dāng)薄弱，南北電網(wǎng)處于分割狀態(tài)，供需矛盾非常突出，隨時(shí)都會(huì)拉閘限電；第二階段，90年代中期，隨著綜合自動(dòng)化變電站的建立，從35KV變電所到110KV甚至

2、500KV的綜合自動(dòng)化變電站建立投用，我國(guó)的電力事業(yè)發(fā)生明顯變化。近年來(lái)，電網(wǎng)日益堅(jiān)強(qiáng)，科技不斷進(jìn)步，變電站有著飛速的發(fā)展，變電站實(shí)現(xiàn)集控化已成為變電站的一種發(fā)展趨勢(shì)。近年來(lái)，各國(guó)均對(duì)變電站的設(shè)計(jì)及使用技術(shù)進(jìn)行了深入的研究，并取得了卓越的理論成就，離高效穩(wěn)定節(jié)能的標(biāo)準(zhǔn)逐漸縮小距離?，F(xiàn)在是跨世紀(jì)的時(shí)代，科技的發(fā)展使變電站設(shè)備的科技含量也越來(lái)越高，新型的、多功能的變電站設(shè)備也相繼出現(xiàn)。如沈陽(yáng)昊誠(chéng)ZB-F系列箱式變，體積僅為國(guó)產(chǎn)常規(guī)箱式變的1/31/5；安全性高，產(chǎn)品無(wú)裸露帶電部分，為全封閉、全絕緣結(jié)構(gòu)，完全能達(dá)到零觸電事故；防滲漏、防腐蝕。河北電力設(shè)備廠生產(chǎn)的10110kV箱式變，設(shè)有“四遙”可無(wú)

3、人值守。VFI(VacuumFault Interrupter Transformer)美式箱式變也以其獨(dú)到的優(yōu)勢(shì)擠身于中國(guó)市場(chǎng)，如：最大容量可達(dá)10000kVA，可用手動(dòng)或電動(dòng)操作，并進(jìn)而與SCADA系統(tǒng)結(jié)合，使技術(shù)逐步升級(jí)。此外，近年來(lái), 計(jì)算機(jī)技術(shù)和電子信息技術(shù)在電力建設(shè)中的應(yīng)用越來(lái)越廣泛, 變電站自動(dòng)化技術(shù)也已經(jīng)達(dá)到一定的水平, 隨著智能化開關(guān)、光電式電流電壓互感器、一次運(yùn)行設(shè)備在線狀態(tài)檢測(cè)、變電站運(yùn)行操作培訓(xùn)仿真等技術(shù)日趨成熟, 以及計(jì)算機(jī)高速網(wǎng)絡(luò)在實(shí)時(shí)系統(tǒng)中的開發(fā)應(yīng)用, 勢(shì)必對(duì)已有的變電站自動(dòng)化技術(shù)產(chǎn)生深刻的影響, 全數(shù)字化的變電站自動(dòng)化系統(tǒng)也即將出現(xiàn)。電力工業(yè)是國(guó)民經(jīng)濟(jì)發(fā)展中最重

4、要的基礎(chǔ)能源產(chǎn)業(yè)，是國(guó)民經(jīng)濟(jì)的第一基礎(chǔ)產(chǎn)業(yè)，是關(guān)系國(guó)計(jì)民生的基礎(chǔ)產(chǎn)業(yè)，是世界各國(guó)經(jīng)濟(jì)發(fā)展戰(zhàn)略中的優(yōu)先發(fā)展重點(diǎn)。作為一種先進(jìn)的生產(chǎn)力和基礎(chǔ)產(chǎn)業(yè)，電力行業(yè)對(duì)促進(jìn)國(guó)民經(jīng)濟(jì)的發(fā)展和社會(huì)進(jìn)步起到重要作用。與社會(huì)經(jīng)濟(jì)和社會(huì)發(fā)展有著十分密切的關(guān)系，它不僅是關(guān)系國(guó)家經(jīng)濟(jì)安全的戰(zhàn)略大問(wèn)題，而且與人們的日常生活、社會(huì)穩(wěn)定密切相關(guān)。隨著我國(guó)經(jīng)濟(jì)的發(fā)展，對(duì)電的需求量不斷擴(kuò)大，電力銷售市場(chǎng)的擴(kuò)大又刺激了整個(gè)電力生產(chǎn)的發(fā)展。隨著科學(xué)技術(shù)的發(fā)展和能源經(jīng)濟(jì)利用的需要，變電站的設(shè)計(jì)在逐步向經(jīng)濟(jì)、穩(wěn)定的方向發(fā)展。迄今為止，變電所的更新設(shè)計(jì)在國(guó)內(nèi)外也正在逐漸形成一個(gè)與人類生活密不可分的行業(yè)。 優(yōu)良更新的設(shè)計(jì)不僅具有標(biāo)準(zhǔn)化、高效化、

5、組合化等當(dāng)代先進(jìn)設(shè)計(jì)思想,又符合節(jié)約有效利用資源的原則,更適合當(dāng)代社會(huì)發(fā)展的要求。所以是今后電力技術(shù)的一個(gè)重要發(fā)展方向。變電站的發(fā)展現(xiàn)狀變電站自動(dòng)化技術(shù)經(jīng)過(guò)10 多年的發(fā)展已經(jīng)達(dá)到了一定的水平, 在我國(guó)城鄉(xiāng)電網(wǎng)改造與建設(shè)中不僅中低壓變電站采用了自動(dòng)化技術(shù), 實(shí)現(xiàn)無(wú)人值班, 而且在220kV 及以上的超高壓變電站建設(shè)中也大量采用綜合自動(dòng)化新技術(shù), 從而提高了電網(wǎng)建設(shè)的現(xiàn)代化水平, 增強(qiáng)了輸配電的可能性, 降低了變電站建設(shè)的總造價(jià)。隨著智能化開關(guān)、光電式電流電壓互感器、一次運(yùn)行設(shè)備在線狀態(tài)檢測(cè)、變電站運(yùn)行操作培訓(xùn)仿真等技術(shù)日趨成熟以及計(jì)算機(jī)高速網(wǎng)絡(luò)在實(shí)時(shí)系統(tǒng)中的開發(fā)應(yīng)用, 勢(shì)必對(duì)已有的變電站自動(dòng)化

6、技術(shù)產(chǎn)生深刻的影響, 全數(shù)字化變電站自動(dòng)化系統(tǒng)即將出現(xiàn)。數(shù)字化變電站自動(dòng)化系統(tǒng)發(fā)展中的主要問(wèn)題：數(shù)字化變電站自動(dòng)化系統(tǒng)的研究目前處于基礎(chǔ)階段, 主要集中在過(guò)程層方面, 諸如智能化開關(guān)設(shè)備、光電互感器、狀態(tài)檢測(cè)等技術(shù)與設(shè)備的研究開發(fā)。目前存在的主要問(wèn)題是: 研究開發(fā)過(guò)程中專業(yè)協(xié)作需要加強(qiáng), 比如智能化電器的研究至少存在機(jī)、電、光三個(gè)專業(yè)協(xié)同攻關(guān)。材料器件方面的缺陷及改進(jìn)。試驗(yàn)設(shè)備、測(cè)試方法、檢驗(yàn)標(biāo)準(zhǔn), 特別是EMC (電磁干擾與兼容) 控制與試驗(yàn)還是薄弱環(huán)節(jié)。我國(guó)電力工業(yè)自動(dòng)化水平正在逐年提高。20 MW及以上大型機(jī)組以采用計(jì)算機(jī)監(jiān)控系統(tǒng)，許多變電所以裝設(shè)微機(jī)綜合自動(dòng)化系統(tǒng)，有些已實(shí)現(xiàn)無(wú)人值班，

7、電力系統(tǒng)已實(shí)現(xiàn)調(diào)度自動(dòng)化。迄今，我國(guó)電力工業(yè)已進(jìn)入了大機(jī)組，大電廠，大電力系統(tǒng)，高電壓和高自動(dòng)化的新階段。我國(guó)在城鄉(xiāng)電網(wǎng)改造與建設(shè)中不僅中低壓變電站采用了自動(dòng)化技術(shù)實(shí)現(xiàn)無(wú)人值班,而且在220kV及以上的超高壓變電站建設(shè)中也大量采用自動(dòng)化新技術(shù),從而大大提高了電網(wǎng)建設(shè)的現(xiàn)代化水平,增強(qiáng)了輸配電和電網(wǎng)調(diào)度的可能性,降低了變電站建設(shè)的總造價(jià),這已經(jīng)成為不爭(zhēng)的事實(shí),也是目前變電站建設(shè)的主要模式. 綜合自動(dòng)化的系統(tǒng)性要求極強(qiáng),特別是結(jié)合了全站的操作防誤系統(tǒng),要求變電站建設(shè)一期工程越齊越好,而這在高電壓等級(jí)的變電站建設(shè)中幾乎是不可能的；擴(kuò)建工程的操作防誤閉鎖邏輯實(shí)際驗(yàn)證困難,特別是牽涉到母線類的；一次設(shè)備

8、電動(dòng)操作全部受控于監(jiān)控系統(tǒng).監(jiān)控系統(tǒng)的誤動(dòng)出口必須絕對(duì)禁止,對(duì)IO設(shè)備的運(yùn)行可靠性要求很高；這是目前國(guó)內(nèi)外在變電所設(shè)計(jì)中所面臨的問(wèn)題與挑戰(zhàn)。變電所綜合自動(dòng)化已成為當(dāng)前變電所設(shè)計(jì)應(yīng)用中的熱門課題和發(fā)展的必然趨勢(shì)。在一些工業(yè)發(fā)達(dá)國(guó)家中，配電自動(dòng)化系統(tǒng)受到了廣泛的重視，國(guó)外的配電自動(dòng)化系統(tǒng)已經(jīng)形成了集變電所自動(dòng)化、饋線分段開關(guān)測(cè)控、電容器組調(diào)節(jié)控制、用戶負(fù)荷控制和遠(yuǎn)方抄表等系統(tǒng)于一體的配電網(wǎng)管理系統(tǒng)（DMS），其功能已多達(dá)140余種。從國(guó)外配電自動(dòng)化系統(tǒng)采用的通信方式看，尚沒有一種通信技術(shù)可以很好地滿足于配電系統(tǒng)自動(dòng)化所有層次的需要。在一個(gè)配電自動(dòng)化系統(tǒng)內(nèi)，往往由多種通信技術(shù)組合成綜合的通信系統(tǒng)，各

9、個(gè)層次按實(shí)際需要采用合適的通信方式。研究?jī)?nèi)容 變電站設(shè)計(jì)主要根據(jù)用電的要求電壓等級(jí)來(lái)選擇合理的變壓器和母線的設(shè)置，來(lái)實(shí)現(xiàn)變換電壓、接受和分配電能、控制電力的流向和調(diào)整電壓的電力設(shè)施，通過(guò)變壓器將各級(jí)電壓的電網(wǎng)聯(lián)系起來(lái)。主要解決的問(wèn)題有：1、變壓器的選擇 2、母線的選擇 3、短路電流的計(jì)算 4、繼電保護(hù)裝置的選擇 5、隔離開關(guān)、斷路器的選擇 6、避雷裝置的選擇 7、輸電線的選擇 8、電流電壓互感器的選型 9、一次接線圖、二次接線圖的繪制對(duì)專變電站設(shè)計(jì)，可以了解變電所在變換和分配電能中的作用：可靠地保證整個(gè)電力系統(tǒng)的安全運(yùn)行與經(jīng)濟(jì)效率，通過(guò)變電站的合理設(shè)計(jì)和配置充分發(fā)揮電網(wǎng)的穩(wěn)固性、可靠性和持續(xù)性

10、。隨著社會(huì)的發(fā)展，科技的不斷提高，眾多技術(shù)逐漸滲透到各個(gè)行業(yè)，如何利用這些高科技為人類服務(wù)，如何充分利用這些高科技在電氣行業(yè)中，使之更好的為我們服務(wù)，這還需要電氣行業(yè)人員不斷的努力，開拓創(chuàng)新。參考文獻(xiàn)：1熊信銀.發(fā)電廠電氣部分.水利電力出版社，1992年2何仰贊等.電力系統(tǒng)分析.華中理工大學(xué)電力出版社，1991年3賀家李等.電力系統(tǒng)及電保護(hù)原理.水利電力出版社，1992年4吳廣寧.高電壓技術(shù).浙江大學(xué)出版社，1994年5雍靜.供配電技術(shù).機(jī)械出版社，1994年6張冠生.電器理論基礎(chǔ).機(jī)械工業(yè)出版社，1991年7楊有啟.電氣安全規(guī)程.北京出版社，1991年8劉從愛.電力工程.機(jī)械工業(yè)出版社，19

11、92年9王崇林、鄒有明主編.供電技術(shù).煤炭工業(yè)出版社，1996年10李軍年.電力系統(tǒng)繼電保護(hù).水利電力出版社，1991年11國(guó)家標(biāo)準(zhǔn)GB50059-1992.35-110kV變電所設(shè)計(jì)規(guī)范.中國(guó)標(biāo)準(zhǔn)出版社，1992年12趙成軍,解玉龍.電力系統(tǒng)繼電保護(hù)方向性分析J.科技資訊.2011(23)13薄艷云,王鵬,薄艷平.35KV變電站綜自改造中常見問(wèn)題改造對(duì)策及綜自系統(tǒng)運(yùn)行維護(hù)中常見問(wèn)題J.中國(guó)新通信.2013(05)14張寶歸.35KV變電站的接地系統(tǒng)設(shè)計(jì)與施工問(wèn)題研究J.低碳世界.2013(12)15張華,郝建奇.35kV變電站防雷與接地分析J.中國(guó)電業(yè)(技術(shù)版).2013(04)外文文獻(xiàn)Ge

12、neral 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 vol

13、tage 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 110-22

14、0kV 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 entrance

15、s 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

16、 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 los

17、ses 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 semicon

18、ductor rectifiers are most economic. Distribution substations for 6-10kV 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 switch-gears for 6-1

19、0kV 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 giv

20、en 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

21、 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

22、 .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 .t

23、ransformers 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 maxim

24、um 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.

25、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 systems only to ensure a reliable and economic power supply;2. Wide use of unitized constru

26、ctions 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

27、 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

28、 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 choos

29、e 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 fl

30、owed 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 1

31、909,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

32、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 e

33、lectricity 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

34、 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

35、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 a

36、tom. 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,

37、 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

38、.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 an

39、d Henry discovered how magnets could be used to make electricity flow in a wire.Magnets Almost 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 obj

40、ects. 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

41、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 wires-that is, how to make

42、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

43、 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 magne

44、tic 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 electric

45、ity).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 thel

46、ined 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.變電站建設(shè)的一般要求變電站(所)在電源系統(tǒng)的工業(yè)企業(yè)是一個(gè)至關(guān)重要的因素。他們接收,轉(zhuǎn)換和發(fā)送電能。根據(jù)能源和需求,變電站分為中央配電變電站電壓為110-500kV；主要降壓變電所電壓為1

47、10-220/6-10-35kV； 深入口變電站為110-330/6-10kV；二次變電站的電壓為6-10Kv；車間變電所電壓為6-10/0.38-0.66kV。在主要的降壓變電所,電源能量轉(zhuǎn)化電壓為110-220kV，通常使用6-10Kv(有時(shí)為35kV變電所)的電壓分配給企業(yè)和被用來(lái)滿足高壓服務(wù)。中央配電變電站從電力系統(tǒng)接收能量并分發(fā)它(不包括或者包括部分變換) 給企業(yè)不同區(qū)域，通過(guò)空中電纜和地下電纜線路電壓為110-220kV。 中央分配變電站站不同于主配電變電它是一個(gè)更強(qiáng)大的電力設(shè)施,它的電壓大部分在110-220kV的電壓。它可以簡(jiǎn)化初級(jí)電壓、中級(jí)電壓或地區(qū)的開關(guān)電路。中低級(jí)別變電站

48、改造能量來(lái)自6-10kv的電壓,它的二次側(cè)電壓為380/220或660/380。升壓變壓器變電站用于將電廠產(chǎn)生的能量轉(zhuǎn)化使發(fā)電機(jī)產(chǎn)生的電壓升高,從而有效地減少在遠(yuǎn)距離輸電能量的損失轉(zhuǎn)換器變電站的目的是為了將直流轉(zhuǎn)換成交流(有時(shí)相反)和轉(zhuǎn)換成能量時(shí)改變頻率。轉(zhuǎn)換器變電站的能量轉(zhuǎn)換是用半導(dǎo)體整流器來(lái)變頻的。帶半導(dǎo)體整流器的轉(zhuǎn)化器變電站是最經(jīng)濟(jì)的。6-10kV的配電變電站主要依據(jù)主配電變電站(有時(shí)依據(jù)中央配電變電站)。110-220kV變電站系統(tǒng)區(qū)域的劃分時(shí)，根據(jù)變電站設(shè)備功能劃分時(shí)是有學(xué)問(wèn)的，6-10kV的變電站設(shè)備劃分在變電站的入口。根據(jù)變電站變的位置，電站設(shè)備在可以露天或室內(nèi)。6-10kV變電

49、站的在電纜的類型主要是供給輸出線。在35-220kV變電站空中線路樣式,在變電站架線和接線,主要注重供電生產(chǎn)的可靠和經(jīng)濟(jì)。用工業(yè)的方式建設(shè)變電站，是使用大量的數(shù)塊和在電氣工程組織和工廠電氣工程等行業(yè)的車間的位置進(jìn)行組裝。變電站通常是專為不連續(xù)操作的責(zé)任人員所設(shè)計(jì),但用的是基本的自動(dòng)設(shè)備和信號(hào)裝置。當(dāng)建立變電站結(jié)構(gòu)的一部分,應(yīng)當(dāng)采用薄型建造結(jié)構(gòu)以及由彎段組成的組件(板材、地板等)。這些元件是預(yù)先安裝區(qū)外面建造區(qū)域并且只是在這個(gè)位置組裝。這樣可以有效的削減變電所建造成本。變電站基本電路概念設(shè)計(jì)的選擇,是根據(jù)企業(yè)的供電系統(tǒng)特點(diǎn)得到的。變電站電壓特性主要入口，變壓器和輸出電纜線路導(dǎo)線或當(dāng)前導(dǎo)體的二次電

50、壓.變電站安裝的設(shè)備和元件，設(shè)備和元件的若干種可能的組合是非常好的。當(dāng)闡述了變電站的電路時(shí)爭(zhēng)取切換裝置最大的簡(jiǎn)化和數(shù)目的最小化。這樣的變電站更可靠、經(jīng)濟(jì)。電路簡(jiǎn)化是采用自動(dòng)接入或自動(dòng)轉(zhuǎn)入儲(chǔ)備的方法,允許快速和無(wú)錯(cuò)誤的自動(dòng)接入每一個(gè)元件和使用設(shè)備。當(dāng)設(shè)計(jì)工業(yè)企業(yè)全電壓變電站時(shí),下面的基本因素都要考慮在內(nèi)。1.優(yōu)先使用采用兩編組的單總線系統(tǒng)可以確?？煽康暮徒?jīng)濟(jì)的供應(yīng)電力。2.配套建設(shè)和變電站廣泛使用。3.變電站使用自動(dòng)化并且支持遙測(cè)技術(shù);如果變電站的設(shè)計(jì)并不支持使用自動(dòng)化或遙測(cè)、線路安而且不允許添加設(shè)備，確保以后沒有過(guò)度投資和返工。4.使用簡(jiǎn)單、便宜的裝置，有絕緣裝置的斷路器、短路開關(guān)、過(guò)載保護(hù)隔

51、離器、保險(xiǎn)絲,預(yù)期到他們的交換容量可考慮大幅度削減昂貴的器件需要和臨界油、真空、螺線管和空氣開關(guān)電路使用。變電站和開關(guān)電路,采用這樣的設(shè)備的每個(gè)生產(chǎn)線服從個(gè)體變壓器、裝配、允許他們同時(shí)的斷開而不破壞斷開連接的生產(chǎn)流程的機(jī)制的線條。變電站的線路的意義,最重要的一點(diǎn)是要妥善安排與選擇轉(zhuǎn)換器件(開關(guān)、隔離者、電流限制器等、避雷器、高低壓熔斷器),這決定了變電站的目的、功能和意義。很多年以前，科學(xué)家們對(duì)電仍只有很模糊的概念。他們之中不少人認(rèn)為電是一種“流體”，這種流體就像水流經(jīng)管道一樣流過(guò)導(dǎo)線。但他們并不了解是什么東西使電流動(dòng)。他們之中的許多人覺得電是有某種極小的微粒構(gòu)成的，但試圖把電分離成單個(gè)的小顆

52、粒他們卻束手無(wú)策。此后，以為偉大的美國(guó)科學(xué)家密利坎于1909年，真正地稱出了單個(gè)的電粒子的重量并算出它的電荷而使科學(xué)界震驚不已。這可能是人類做過(guò)的最細(xì)致的計(jì)量工作之一，因?yàn)橐粋€(gè)單個(gè)的電粒子的重量?jī)H為一磅的百萬(wàn)分之一，百萬(wàn)分之一的一半左右的重量。要合成一磅重需要的電粒子數(shù)將要比大西洋的全部水的水滴數(shù)還要多。這些電粒子，他們對(duì)我們并不陌生，因?yàn)槲覀冎浪麄兙褪请娮印．?dāng)大量電子擺脫原子跑出來(lái)并通過(guò)導(dǎo)線運(yùn)動(dòng)時(shí)，我們把這種現(xiàn)象說(shuō)成是電通過(guò)導(dǎo)線“流動(dòng)”。是的，早先的科學(xué)家所說(shuō)的電的“流體”只不過(guò)是沿著導(dǎo)線流動(dòng)的電子。那么，如何能使一些單個(gè)的電子擺脫原子的束縛而跑出來(lái)呢？而且，又怎樣能使這些自由電子沿導(dǎo)線運(yùn)

53、動(dòng)呢？第一個(gè)問(wèn)題的答案就在于原子本身的結(jié)構(gòu)上。某些原子的結(jié)構(gòu)使他們很容易失去電子。例如，一個(gè)銅原子在正常情況下有29個(gè)電子，它們排列在核子周圍的4個(gè)不同的軌道上。最里層的軌道上有2個(gè)電子。第二層較大的軌道上有8個(gè)電子。第三層軌道上擠滿18個(gè)電子。而外層軌道上只有一個(gè)電子。正是這個(gè)外層電子，銅原子不斷丟掉它，因?yàn)檫@個(gè)電子受原子的約束不那么緊。它忽而游離而去，并被另一游離的電子所替代，然后，這后一個(gè)電子也游離而去。結(jié)果，在銅導(dǎo)線中自由電子在銅原子之間向四面八方漂浮。所以，盡管對(duì)你們的普通的肉眼來(lái)說(shuō)，銅導(dǎo)線看來(lái)是完全不動(dòng)的，但在它內(nèi)部卻不斷地進(jìn)行著大量的活動(dòng)。如果導(dǎo)線把電輸送到一盞電燈或者另外某個(gè)電

54、氣設(shè)備那里，這些電子就不會(huì)雜亂無(wú)章地到處跑來(lái)跑去，而是它們中的許多電子將會(huì)向一個(gè)方向奔去-從導(dǎo)線的一端奔向另一端。這就把我們引向第二個(gè)問(wèn)題，如何才能使自由電子沿導(dǎo)線運(yùn)動(dòng)呢？好啦，人們已經(jīng)找到幾種方法來(lái)做到這一點(diǎn)。一種就是化學(xué)方法。伏特電堆，或者叫電池，就是能使電流在導(dǎo)線中流動(dòng)的一種化學(xué)裝置。另一種方法就是電磁法。法拉第和亨利發(fā)現(xiàn)了怎樣能把磁鐵用來(lái)使電在導(dǎo)線中流動(dòng)的辦法。磁鐵幾乎每個(gè)人都見過(guò)馬蹄形磁鐵-之所以這樣叫他是因?yàn)樗麄兊男螤钭龀神R蹄形的?？赡苣銈兌加么盆F做過(guò)試驗(yàn)，并且看到它是怎樣吸起按釘，小釘子或者其他一些小鐵件的。人們了解磁鐵已經(jīng)幾千年了。據(jù)傳說(shuō)，幾千年前有個(gè)名叫麥格尼斯的牧羊人住在地

55、中海的克里特島上。他有一根牧羊人用的帶鐵頭的棍杖。一天，他發(fā)現(xiàn)一塊奇形怪狀的黑石頭黏在鐵頭上。后來(lái)，當(dāng)又發(fā)現(xiàn)許多這種石頭時(shí)，人們就叫它們?yōu)榇盆F。這些就是天然磁鐵。近年來(lái)，人們已經(jīng)掌握怎樣使用鐵來(lái)制成磁鐵。尤其重要的是，人們發(fā)現(xiàn)了如何使用磁鐵推動(dòng)電子通過(guò)導(dǎo)線-也就是怎樣使電流動(dòng)。在我們討論這點(diǎn)之前，磁鐵有某些特性我們應(yīng)當(dāng)了解。如果把一塊玻璃放在馬蹄形磁鐵的端部，然后把一些鐵粉末撒在玻璃上，那么鐵粉自己就會(huì)排成許多線。如果用一根棒做的話，就更容易看出這些鐵粉排成的線條了。這些實(shí)驗(yàn)演示了科學(xué)家們所謂的磁力線。他們解釋說(shuō)。磁鐵通過(guò)磁鐵兩端之間延伸出來(lái)的磁力線起作用。但是，在電子周圍似乎也有磁力線。把一根導(dǎo)線穿過(guò)一塊硬紙板，在紙板上撒上鐵粉，并把電池與導(dǎo)線連通在一起，這點(diǎn)就可以得到證明。由于運(yùn)動(dòng)的電子的磁性的結(jié)果，鐵粉就會(huì)繞導(dǎo)線周圍形成一些圓環(huán)。因此，我們可以看到，在運(yùn)動(dòng)者的電子和磁性之間有一種關(guān)系。磁性就是由電子的運(yùn)動(dòng)引起的。當(dāng)然，電子并不是在磁棒里真的“流動(dòng)”，但它們卻是在運(yùn)動(dòng)，在繞鐵原子核做旋轉(zhuǎn)運(yùn)動(dòng)。然而，在磁鐵中，原子都排列的使它們的電子都向同一方向旋轉(zhuǎn)。也許可打一個(gè)恰當(dāng)?shù)谋扔?，就像許多小孩在他們頭頂上以順時(shí)針?lè)较蛩?dòng)系在線上的小球一樣。