【正文】
oltage 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 voltage。防雷保護(hù)設(shè)計(jì),參照設(shè)計(jì)要求利用滾球法為防雷保護(hù)的設(shè)計(jì)方法,并且采用四支等高等距離的避雷針。(6)35kV配電裝置在土壤電阻率不大于500m的地區(qū)允許將線路的避雷線接至于出線門型架構(gòu)上但要裝設(shè)集中接地裝置。防雷電波侵入:1)地電線路全長(zhǎng)采用埋地電纜或敷設(shè)架空金屬線槽內(nèi)的電纜引入時(shí),在入戶端應(yīng)將金屬電纜外皮,金屬線槽接地。雷電的破壞作用主要是雷電波過(guò)電壓引起的,主要表現(xiàn)在以下幾個(gè)方面:1.雷電的熱效應(yīng) 雷電流產(chǎn)生的熱量,可能燒斷導(dǎo)線和燒毀電力設(shè)備;2.雷電的機(jī)械效應(yīng) 雷電流產(chǎn)生的電動(dòng)力,可摧毀設(shè)備、桿塔、建筑物和傷害人;3.雷電的電磁效應(yīng) 雷電過(guò)電壓將會(huì)使電氣絕緣被擊穿,甚至引起火災(zāi)和燃燒,造成人身傷亡和設(shè)備損壞。17S GGD36G柜包括:A樓負(fù)二層電力、B樓負(fù)一層電力、備用、備用。9S GGD36G柜包括:A樓消防電力干線備用、A樓消防照明干線、B樓消防照明干線、B樓進(jìn)風(fēng)機(jī)、直流屏電源高壓柜內(nèi)照明、備用。遼寧工學(xué)院的綜合樓變電所為屋內(nèi)配電裝置;框如圖91下所示:圖91高壓側(cè)配電裝置圖如圖92其中1S GGD36G柜包括:B樓負(fù)一層照明、B樓一層照明、B樓二層照明、B樓三層照明、B樓四層照明、B樓五層計(jì)算機(jī)房、備用。當(dāng)系統(tǒng)中發(fā)生故障時(shí)能迅速切斷故障部分,維持系統(tǒng)正常運(yùn)行。保護(hù)動(dòng)作電流的整定值有兩個(gè)原則:(1) 躲過(guò)變壓器二次測(cè)母線上K1處故障時(shí)流過(guò)保護(hù)的最大短路電流,即 式中 -可靠系數(shù),-。設(shè)計(jì)中所選用的變壓器型號(hào)為SCB91000/10變壓器,10KV/,干式變壓器,其中電流互感器電流比為其過(guò)電流整定值計(jì)算如下所示:電流整定值:,過(guò)電流保護(hù)繼電器選用DL11/11型。動(dòng)作于跳閘線圈的繼電保護(hù)在技術(shù)上一般滿足以下幾個(gè)方面:1. 選擇性它是繼電保護(hù)裝置動(dòng)作時(shí),僅將故障元件從電力系統(tǒng)中切除,保證系統(tǒng)非故障元件仍繼續(xù)運(yùn)行,盡量減小停電范圍。2.電壓互感器校驗(yàn)為了保證電壓互感器的安全運(yùn)行和在規(guī)定的準(zhǔn)確級(jí)下運(yùn)行,電壓互感器一次繞組所接電網(wǎng)電壓互感器應(yīng)滿足下列條件:其中式中 為電網(wǎng)電壓; 為電壓互感器一次繞組額定電壓;其電壓互感器參數(shù)如下表所示表75 電壓互感器參數(shù)型號(hào)額定電壓(KV)一次繞組額定容量(VA)二次繞組額定容量(VA)最大容量(VA)JDZ1810一次二次133P6P400105080200綜合公式: 校驗(yàn)后滿足要求。電流互感器一、二次額定電流之比叫變流比,用表示,由變壓器的基本知識(shí)可知: (71)式中 、——電流互感器一、二次繞組的匝數(shù);、——電流互感器一、二次額定電流;、——電流互感器一、二次實(shí)際電流;由式71可見(jiàn),若已知電流互感器的變流比(或一、二次繞組的匝數(shù))和二次實(shí)際電流,便可計(jì)算出一次實(shí)際電流的近似值。(2)按比例減小電流和降低電壓電流互感器是將一次大電流按比例變成二次小電流的裝置?;ジ衅靼娏骰ジ衅骱碗妷夯ジ衅鲀纱箢?,主要是電磁式的。(4).觸頭罩無(wú)異物堵塞。表72 ZN1210I型高壓真空斷路器序號(hào)安裝電氣條件ZN1210I校驗(yàn)結(jié)論項(xiàng)目數(shù)據(jù)項(xiàng)目技術(shù)數(shù)據(jù)110KV10KV合格21250A合格3合格425KA合格5126合格 隔離開(kāi)關(guān)是發(fā)電廠和變電所中常用的開(kāi)關(guān)電器,用于隔離電源,以保證對(duì)其它電器設(shè)備和線路運(yùn)行安全檢修。在供配電系統(tǒng)中盡管各種電器設(shè)備的作用不一樣,但選擇的條件有諸多是相同的,在表71中列出了導(dǎo)體和電器選擇與校驗(yàn)的項(xiàng)目。電氣設(shè)備電氣設(shè)備是指電力系統(tǒng)中發(fā)電、輸電、變配電、用電設(shè)備的總稱,它包括發(fā)電機(jī)、變壓器及各種高低壓開(kāi)關(guān)設(shè)備、保護(hù)設(shè)備、導(dǎo)線、電纜和用電設(shè)備等。 圖61電力系統(tǒng)短路計(jì)算電路圖計(jì)算短路前給定電力系統(tǒng)饋線出口短路器2QF為2N1210I型。,同時(shí)也使導(dǎo)體受到很大的電動(dòng)力作用、使導(dǎo)體發(fā)生變形,甚至損壞。在電氣設(shè)計(jì)和運(yùn)行中,不僅要考慮系統(tǒng)正常運(yùn)行狀態(tài),而且要考慮它發(fā)生故障時(shí)的情況,最嚴(yán)重的故障是電路乃至系統(tǒng)發(fā)生短路。這在主接線的選擇上確定了范圍,根據(jù)510年的發(fā)展計(jì)劃設(shè)計(jì),并依據(jù)遼寧工學(xué)院的供電情況,擬裝設(shè)兩臺(tái)主變壓器。二、單母線分段接線為了克服一般單母線接線存在的缺點(diǎn),提高它的供電可靠性和靈活性,可以把單母線分成幾段,在每段母線之間裝設(shè)一個(gè)分段斷路器和兩個(gè)隔離開(kāi)關(guān)。接地開(kāi)關(guān)(又稱接地刀間)QS4是在檢修電路和設(shè)備時(shí)合上,取代安全接地線的作用。隔離開(kāi)關(guān)沒(méi)有滅弧裝置.其開(kāi)合電流能力極低,只能于設(shè)備停運(yùn)后退出工作時(shí)斷開(kāi)電路,保證與帶電部分隔離,起著隔離電壓的作用。無(wú)匯流母線的接線使用開(kāi)關(guān)電器較少,占地面積小,但只適用于進(jìn)出線回路少,不再擴(kuò)建和發(fā)展的變電所。 (6)繪制電氣主接線圖及其他必要的圖紙。(2)擬定主接線方案。因?yàn)樨?fù)荷的發(fā)展和增長(zhǎng)速度受政治、經(jīng)濟(jì)、工業(yè)水平和自然條件等方面影響。在各階段中隨要求、任務(wù)的不同,其深度、廣度也有所差異,但總的設(shè)計(jì)思路、方法和步驟相同。2.考慮近期和遠(yuǎn)期的發(fā)展規(guī)模變電所主接線設(shè)計(jì)應(yīng)根據(jù)5—10年電力系統(tǒng)發(fā)展規(guī)劃進(jìn)行??梢造`活的投入和切除變壓器、線路、調(diào)配電源和負(fù)荷,能夠滿足系統(tǒng)在事故運(yùn)行方式下、檢修方式下以及特殊運(yùn)行方式下的調(diào)度要求。對(duì)電氣主接線的基本要求概括地說(shuō)應(yīng)包括電力系統(tǒng)整體及變電所本身運(yùn)行的可靠性、靈活性和經(jīng)濟(jì)性。8. 壽命期后,不易回收,污染環(huán)境。由于干式變壓器的適用材料不同,其絕緣等級(jí)也不同,絕緣材料等級(jí)與絕緣材料最高允許溫度見(jiàn)表42。按負(fù)荷的等級(jí)和大小來(lái)說(shuō),對(duì)于帶一、二級(jí)負(fù)荷的變電所,當(dāng)一、二級(jí)負(fù)荷較多時(shí),應(yīng)選兩臺(tái)或兩臺(tái)以上變壓器,如只有少量的一、二級(jí)負(fù)荷并能從相鄰的變電所取得低壓備用電源,可以只采用一臺(tái)變壓器。主變壓器選擇;變電所電氣主接線設(shè)計(jì);短路電流計(jì)算;電氣設(shè)備選擇(母線、高壓斷路器、隔離開(kāi)關(guān)、電流互感器、電壓互感器、避雷器和補(bǔ)償電容器);配電裝置設(shè)計(jì);繼電保護(hù)設(shè)計(jì);防雷保護(hù)設(shè)計(jì);繪制電氣主接線圖,繪制配電裝置平面圖及直擊雷保護(hù)范圍圖。以上是理論知識(shí)的體現(xiàn)而更中要的一點(diǎn)是在設(shè)計(jì)中培養(yǎng)自己運(yùn)用所學(xué)知識(shí)解決實(shí)際問(wèn)題的能力和創(chuàng)新精神,增強(qiáng)工程觀,在設(shè)計(jì)過(guò)程中主要立足于應(yīng)用所學(xué)基本理論和專業(yè)知識(shí),大膽地運(yùn)用新理論、新技術(shù)去分析解決實(shí)際問(wèn)題,以便更好地適應(yīng)工作的需要。 Relay . 目 錄前言 VI第1章 畢業(yè)設(shè)計(jì)概述 1 畢業(yè)設(shè)計(jì)題目 1 畢業(yè)設(shè)計(jì)目的 1 1第2章 負(fù)荷計(jì)算 2 2 2第3章 無(wú)功功率補(bǔ)償 7 7 7第4章 主變壓器選擇 臺(tái)數(shù)、型號(hào)選擇 9 9 9 10 10 11 11第5章 變電所電氣主接線 12 12 12 12 13 14第6章 短路計(jì)算 18 18 18 18 19第7章 電氣設(shè)備選擇與校驗(yàn) 23 23 23 24 24 25 26 26 26 26 27 27 28 29 30 30 31 母線的選擇 31 32第8章 繼電保護(hù) 33 33 33 33 34 34 36第9章 配電裝置 38 38 38 38 39第10章 防雷保護(hù)設(shè)計(jì) 42 42 42 42 43 43總 結(jié) 47參考文獻(xiàn) 48致謝