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般為單側(cè)電源,此時注意將電流速斷保護(hù)裝于變壓器電源側(cè)。(2) 躲過變壓器空載合閘時的勵磁涌流?!”Wo(hù)動作電流取上述兩者中最大者。圖81電流速斷保護(hù)原理接線圖圖82電流速斷保護(hù)原理接線圖展開式 式中 ——電流繼電器速斷保護(hù)動作電流(A); ——保護(hù)裝置可靠系數(shù),取=; ——接線系數(shù),取=1; ——電流互感器電流比,=75/5=15; ——線路末端最大短路電流,即三相金屬性短路電流穩(wěn)定性(A);取 ,對于電力系統(tǒng)末端供配電電力變壓器的速斷保護(hù),一般取額定電流的23倍。靈敏度校驗(yàn)公式:;取 ;;(靈敏度合格)第9章 配電裝置配電裝置是發(fā)電廠和變電所的重要組成部分,在電力系統(tǒng)中起著接受和分配電能的作用,它是電氣主接線的連接方式,由開關(guān)電氣、保護(hù)和測量電氣、母線和必要的輔助設(shè)備組建而成的總體裝置。1. 保證運(yùn)行可靠;2. 便于操作、巡視和檢修;3. 保證工作人員的安全;4. 力求提高經(jīng)濟(jì)性;5. 具有擴(kuò)建的可能;配電裝置按電氣設(shè)備裝設(shè)的地點(diǎn)不同,可分為屋內(nèi)配電裝置和屋外配電裝置;按其組裝方式,又可分為裝配式和成套式。在發(fā)電廠和變電站中,35kV以下的配電裝置多采用屋內(nèi)配電裝置,其中310kV的大多采用成套配電裝置;110kV及以上的大多采用屋外配電裝置;對于110220kV的配電裝置有特殊要求時,如建于城市中心也可以采用屋內(nèi)配電裝置。并考慮各種配電裝置的典型設(shè)計和手冊,設(shè)計繪制配電裝置平面圖和斷面圖。2S GGD36G柜包括:B樓六層計算機(jī)房、B樓七層照明、B樓八層照明、B樓九層照明、備用、備用。4S GGD08G柜包括:段受電。6S 柜包括:無功優(yōu)化補(bǔ)償裝置。圖92 1變壓器配電裝置圖如圖93為2變壓器配電裝置圖8S GGD09G柜包括:消防電梯1備用、消防電梯正壓風(fēng)機(jī)、消防污水泵、B樓負(fù)一層人防電力備用、備用、變點(diǎn)所用電。10S GGD09G柜包括:母線聯(lián)絡(luò)。12S GGD36G柜包括:A樓消防電力干線、A樓消防照明干線備用、B樓消防照明干線、B樓進(jìn)風(fēng)機(jī)備用、直流屏電源備用、備用。14S 柜:無功優(yōu)化補(bǔ)償裝置。16S GGD08G柜包括:段受電。18S GGD36G柜包括:B樓負(fù)二層電力、B樓三層電力、B樓四層電力、備用。雷云放電在電網(wǎng)(或者電力系統(tǒng))中引起的過電壓,統(tǒng)稱雷電過電壓由于這種過電壓和電網(wǎng)的工作電壓本身沒有直接關(guān)系,其所需要的電磁場能量來自電網(wǎng)外部,所以又稱為外部過電壓,又由于雷云放電發(fā)生在大氣中,所以這種過電壓也成為大氣過電壓。雷電過電壓又分為:直擊雷過電壓和感應(yīng)雷過電壓。感應(yīng)雷過電壓的幅值不太高,一般不超過500600kV,它主要對35kV及以下電網(wǎng)構(gòu)成威脅。另外雷電的閃落放電,可能燒壞絕緣子,使斷路器跳閘,造成停電事故。實(shí)際運(yùn)行表明,對于變配電所防直擊雷的保護(hù)避雷針和避雷器是很有效的,雷電波入侵則必須裝設(shè)閥型避雷器保護(hù),防雷保護(hù)涉及應(yīng)認(rèn)真調(diào)查地質(zhì)地貌氣象環(huán)境等條件和雷電的活動規(guī)律,以及被保護(hù)物的特點(diǎn)等,因地制宜地采取防雷保護(hù)措施,做到安全可靠、技術(shù)先進(jìn)、經(jīng)濟(jì)合理等。圖101為避雷器與被保護(hù)設(shè)備的連接其中 1——相線;2——被保護(hù)設(shè)備;3——避雷針; 4——過電壓波。防雷電感應(yīng):建筑物內(nèi)的設(shè)備管道構(gòu)架等主要建筑物,應(yīng)就近接至防直擊雷接地裝置或電氣設(shè)備的保護(hù)接地裝置上,可不另設(shè)接地裝置。2)低壓架空線轉(zhuǎn)換金屬改裝電纜或護(hù)套電纜穿鋼管直接埋地引入時,其埋地長度應(yīng)大于或等于15m。2.建筑物防雷接閃器有以下幾種形式(1)獨(dú)立避雷針(2)架空避雷線或架空避雷網(wǎng)(3)直接安裝在建筑物上的避雷針避雷帶或避雷網(wǎng)3.變配電所建筑物防雷保護(hù)(1)變配電所屋外配電裝置應(yīng)裝設(shè)防直擊雷保護(hù)裝置,一般采用避雷針或避雷器。(3)35kV及以下的屋外高壓配電裝置,采用獨(dú)立避雷器或避雷線保護(hù),宜裝設(shè)獨(dú)立的接地裝置,接地電阻不宜超過20。(5)35kV及以下高壓配電裝置的架構(gòu)或變電所房頂上不宜裝設(shè)避雷針。(7)獨(dú)立避雷針避雷線與配電裝置帶電部分,變電所電力設(shè)備接地部分、構(gòu)架接地部分之間的空氣距離一般不小于5m,當(dāng)條件允許時應(yīng)盡量增大,以便降低感應(yīng)過電壓。變電所310kV配電裝置(包括電力變壓器)應(yīng)在每組母線和每回架空線路上裝設(shè)發(fā)行避雷器避雷器與變壓器的最大電氣距離雷季經(jīng)常運(yùn)行的進(jìn)出路數(shù)1234及以上最大空氣距離m15232730圖103 架設(shè)避雷線圖104 架空線路上裝設(shè)發(fā)行避雷器5:防雷計算(1) 變電所占地面積,采用4根避雷針保護(hù),為避免反擊,避雷針距離變電所5m。在設(shè)計中電氣主接線根據(jù)原始資料及實(shí)際工程應(yīng)用,分析并選定兩種接線方式,通過實(shí)地考察和供電情況分析,最終選定的接線方式為:高壓側(cè)采用單母線接線,低壓側(cè)采用單母線分段接線,在本變電所的設(shè)計中還對變壓器選擇、短路電流的計算及設(shè)備選擇進(jìn)行了設(shè)計。設(shè)計變壓器繼電保護(hù)時,采用了過電流保護(hù)、速斷保護(hù)。通過完成遼寧工學(xué)院綜合教學(xué)樓的變電所的設(shè)計,把過去所學(xué)的專業(yè)知識綜合的利用起來,并運(yùn)用到了實(shí)際工程當(dāng)中去,把基礎(chǔ)知識與工程實(shí)際相互結(jié)合。參考文獻(xiàn)[1] 熊信銀,發(fā)電廠電氣部分(第三版),北京:中國電力出版社,[2] 陳躍,電氣工程專業(yè)畢業(yè)設(shè)計指南電力系統(tǒng)分冊,北京:中國水利水電出版社,[3] 丁毓山 雷振山,中小型,變電所實(shí)用設(shè)計手冊,北京:中國水利水電出版社,[4] 陳化鋼, 電氣設(shè)備及其運(yùn)行, 合肥: 合肥工業(yè)大學(xué)出版社, 2004[5] 賀家李等, 電力系統(tǒng)繼電保護(hù)原理, 北京:中國電力出版社,2004.[6] 朱獻(xiàn)清, 物業(yè)供用電, 北京:機(jī)械工業(yè)出版社,2003[7] 尹克寧, 變壓器設(shè)計原理, 北京:中國電力出版社,2003[8] :中國水利電力出版社,2002[9] :中國水利電力出版社,2002[10] :中國電力出版社,2004[11] :中國電力出版社,2004[12] . :2327[13] :1418[14] 何仰贊等,電力系統(tǒng)分析,武漢:華中理科技學(xué)出版社, [15] Hologamous Integrating Strategies for Incipient Fault Diagnosis of Transformer,1985[16] Workgroup of GEC AL THOM Measurements. Protective RelaysApplication Guide:3rd Edition . Stafford: GEC AL THOM Protection amp。本次畢業(yè)設(shè)計也是對我整個學(xué)習(xí)階段的一次綜合測試。他們那嚴(yán)謹(jǐn)求實(shí)的教學(xué)作風(fēng)、誨人不倦的耐心,給我留下了難以磨滅的印象。在這四年的大學(xué)生活和學(xué)習(xí)中,老師不僅教導(dǎo)我做人的原則,尤其在學(xué)習(xí)當(dāng)中對我傳授的知識會使我受益終身。附錄Ⅰ英文資料及其翻譯TransformerTypes and Construction of TransformerA transformer is a device that alternating current electric energy at one voltage level into alternating current electric energy at another voltage level through the action of a magnetic consists of two or more coils wire wrapped around a mon ferromagnetic coils are (usually)not directly connected. The only connection between the coils is the mon magnectic flux presen within the core.One of the transformer windings is connected to a source of ac electric power,and the second(and perhaps third) transformer winding supplies electric power to loads. the transformer winding connected to the power souce is called the primary winding or input the winding connected to the loads is called the secondary winding or input there is a third winding on the transformer,it is called the tertiary winding.Power transformer are constructed on one of two types of type of construction consists of a simple rectangular laminated piece of steel with the transformer windings wrapped around two sides of the type of construction is know as coreform .The other type consists of threelegged laminated core with the windings wrapped around the center leg .This type of construction is know as shell either case,the core is constructed of thin laminations electrically isolated form each other in order in order to reduce eddy currents to a minimum.The primary and secondary windings in a physical transformer are wrapped one on top of the other with the lowvoltage winding an arrangement severs two purposes: simplifies the problem of insulating the high voltage winding from the results in much less leakage flux than would be the two windings were separated by a distance on the core.Power transformer are given a variety of different names, depending on their use in power transformer connected to the output of a generator and used to step its voltage up to transformer levels is sometimes called unit transformer. The transformer ai the other end of the transformer line,which steps the voltage down from transmission levels to distribution levels,is called a substation ,the transformer that takes the distribution voltage and steps is down to the final voltage ai which the power is actually used is called a distribution these devices are essentially the samethe only difference among them is their intended use.In addition to the various power transformer, two specialpurpose transformers are used with electric machinery and power first of these special transformers is a device specially designed to sample a high voltage and produce a low secondary voltage directly proportional to a transformer is called a potential power transformer also produces a secondary voltage directly proportional to its primary voltag