【正文】 tIt =()2*4S=625 (kA2 ② 按發(fā)熱條件進(jìn)行校驗(yàn)： 變壓器高壓側(cè)最大長(zhǎng)期工作電流 為： 30I = 查表， 70 mm2 的 LGJ 型鋼芯鋁絞線在 25℃ 、 30℃ 時(shí)的載流量為 275A、 259A，大于 ，故滿足條件。( ) ( ) ( )K K KI I I? ? ? ???= 3()Shi =*= 3()ShI =*= ④ 三相短路容量 32()KS? = 2*d (K )S / X?? =100MVA,因此 1*X = dkS/S =100MV 18 5 短路 電流的計(jì)算 產(chǎn)生短路電流的原因、危害及計(jì)算方法 供電系統(tǒng)應(yīng)該正常的不間斷地可靠供電，以保證生產(chǎn)和生活的正常進(jìn)行。 總之，變電所通過(guò)合理的接線、緊湊的布置、簡(jiǎn)化所內(nèi)附屬設(shè)備，從而達(dá)到減少變電所占地面積，優(yōu)化變電所設(shè)計(jì)，節(jié)約材料，減少人力物力的投入，并能可靠安全的運(yùn)行，避免不必要的定期檢修，達(dá)到降低投資的目的。而在事故情況下，一臺(tái)變壓器承受總計(jì)算 負(fù)荷時(shí)，只過(guò)載 40%，可繼續(xù)運(yùn)行一段時(shí)間。 變壓器類(lèi)型的選擇 電力變壓器類(lèi)型的選擇是指確定變壓器的相數(shù)、調(diào)壓方式、繞組形式、絕緣及冷卻方式、聯(lián)結(jié)組別等。前者主要有同步補(bǔ)償機(jī)和并聯(lián)電容器。A 機(jī)床組 電焊機(jī)組 起重機(jī) 水泵組 176 辦公樓 1 0 24 0 24 住宅區(qū) 1 0 0 廠區(qū)照明 1 1 0 29 0 29 總計(jì) —— —— 對(duì)干線 取 pK? =, QK? = 對(duì)低壓母線 取 pK? =, QK? = 無(wú)功補(bǔ)償?shù)哪康暮头桨? 由于用戶的大量負(fù)荷如感應(yīng)電動(dòng)機(jī)、電焊機(jī)、氣體放電燈等，都是感性負(fù)荷，使得功率因數(shù)偏低，因此需要采用無(wú)功補(bǔ)償措施來(lái)提高功率因數(shù)。 鑒于云錫公司用電的特殊性，新建變電所的電源取自 3km 外云錫公司一專用 35kV 變電站和 3km 外市供電公司另一相同容量的 35kV 變電站。 關(guān)鍵詞 ： 變電所，負(fù)荷， 短路電流 ， 防雷設(shè)計(jì) Abstract The substation is an importance part of the electric power system, it is consisted of the electric appliances equipments and circuitry. It obtains the electric power from the electric power system, through its function of transformation and assign, transport and safety. Then transport the power to every place with safe. The design of substation supplypower distribution should consider many change to give or get an electric shock a mission for carrying and customers carries etc. make good use of customer data proceed then carry calculation, ascertain the correct equipment of the customer. At the same time following the choice of every kind of transformer, then make sure the line method of the substation, then calculate the shortcircuit electric current, choosing the style of the wire and once equipment of electric appliances and so on. This first step of design included:(1) ascertain the total project (2) load analysis(3) the calculation of the shortcircuit electric current (4) the choice of line project (5) the choice and the settle of the protective facility (6) The design of prevent mine Key words： Substation， Load， Shortcircuit electric current， The design of prevent mine 目 錄 1 緒 論 ....................................................................................................................... 1 工廠變配電所的設(shè)計(jì) ..................................................................................... 1 電力用戶供電系統(tǒng)的分類(lèi) .................................................................. 1 工廠變配電所的設(shè)計(jì)原則 .................................................................. 1 課題來(lái)源 .............................................................................................. 2 設(shè)計(jì)背景 .............................................................................................. 2 2．變電所負(fù)荷計(jì)算和無(wú)功補(bǔ)償?shù)挠?jì)算 ..................................................................... 3 計(jì)算負(fù)荷的方法及負(fù)荷計(jì)算法的確定 ...................................................... 3 需要系數(shù)法的基本知識(shí) .............................................................................. 3 變電所的負(fù)荷計(jì)算 ........................................................................................ 5 負(fù)荷統(tǒng)計(jì) .............................................................................................. 5 負(fù)荷計(jì)算 ............................................................................................. 5 無(wú)功補(bǔ)償?shù)哪康暮头桨? ................................................................................. 8 無(wú)功補(bǔ)償?shù)挠?jì)算及電容器的選擇 ................................................................ 8 3 變電所變壓器臺(tái)數(shù)和容量的選擇 ....................................................................... 11 變壓器的選擇原則 ....................................................................................... 11 變壓器類(lèi)型的選擇 ....................................................................................... 11 變壓器臺(tái)數(shù)的選擇 ....................................................................................... 11 變壓器容量的選擇 ....................................................................................... 12 4 電氣主接線方案的設(shè)計(jì) ....................................................................................... 13 主接線的基本要求 ....................................................................................... 13 主接線的基本形式與分析 ........................................................................... 13 變電所主接線方案的選擇 .......................................................................... 15 5 短路電流的計(jì)算 ................................................................................................... 18 產(chǎn)生短路電流的原因、危害及計(jì)算方法 ................................................... 18 高壓電網(wǎng)三相短路計(jì)算 ............................................................................... 18 6 變電所高壓進(jìn)線、一次設(shè)備和低壓線路的選擇與效驗(yàn) ..................................... 22 高壓側(cè)的負(fù)荷計(jì)算 ....................................................................................... 22 ................................................................... 22 .高壓側(cè)的負(fù)荷計(jì)算 ......................................................................... 22 變電所高壓進(jìn)線的選擇與校驗(yàn) ................................................................... 23 架空線的選擇 .................................................................................... 23 電纜進(jìn)線的選擇 ................................................................................ 23 高壓一次設(shè)備的選擇 ................................................................................... 23 高壓斷路器的選擇與效驗(yàn) ................................................................ 24 高壓隔離開(kāi)關(guān)的選擇與效驗(yàn) ............................................................ 26 高壓 熔斷器的選擇與效驗(yàn) ................................................................ 27 電流互感器的選擇與效驗(yàn) ................................................................ 28