【正文】 匝數(shù)比可以衡量二次側(cè)電壓相對(duì)于一次惻電壓是升高或者是降低。正如前文中討論到的，所產(chǎn)生的電壓必定滯后于磁通90186。這就是變壓器的作用。 thereforeVpIp = VsIsfrom which is obtained = ≌ ≌ aIt shows that as an approximation the terminal voltage ratio equals the turns ratio. The primary and secondary current, on the other hand, are inversely related to the turns ratio. The turns ratio gives a measure of how much the secondary voltage is raised or lowered in relation to the primary voltage. To calculate the voltage regulation, we need more information.The ratio of the terminal voltage varies somewhat depending on the load and its power factor. In practice, the transformation ratio is obtained from the nameplate data, which list the primary and secondary voltage under fullload condition.When the secondary voltage Vs is reduced pared to the primary voltage, the transformation is said to be a stepdown transformer: conversely, if this voltage is raised, it is called a stepup transformer. In a stepdown transformer the transformation ratio a is greater than unity (a), while for a stepup transformer it is smaller than unity (a). In the event that a=1, the transformer secondary voltage equals the primary voltage. This is a special type of transformer used in instances where electrical isolation is required between the primary and secondary circuit while maintaining the same voltage level. Therefore, this transformer is generally knows as an isolation transformer.As is apparent, it is the magnetic flux in the core that forms the connecting link between primary and secondary circuit. In section 4 it is shown how the primary winding current adjusts itself to the secondary load current when the transformer supplies a load.Looking into the transformer terminals from the source, an impedance is seen which by definition equals Vp / Ip. From = ≌ ≌ a , we have Vp = aVs and Ip = Is/ terms of Vs and Is the ratio of Vp to Ip is = = But Vs / Is is the load impedance ZL thus we can say thatZm (primary) = a2ZLThis equation tells us that when an impedance is connected to the secondary side, it appears from the source as an impedance having a magnitude that is a2 times its actual value. We say that the load impedance is reflected or referred to the primary. It is this property of transformers that is used in impedancematching applications.4. TRANSFORMERS UNDER LOADThe primary and secondary voltages shown have similar polarities, as indicated by the “dotmaking” convention. The dots near the upper ends of the windings have the same meaning as in circuit theory。朱老師淵博的知識(shí)，豐富的經(jīng)驗(yàn)，認(rèn)真嚴(yán)謹(jǐn)?shù)闹螌W(xué)作風(fēng)使我深深受益，在我做畢業(yè)設(shè)計(jì)的整個(gè)過(guò)程中，朱老師給我了我很大的幫助，每當(dāng)我的設(shè)計(jì)無(wú)法進(jìn)行遇到困難時(shí)，朱老師總會(huì)為我們提供各種寶貴的意見(jiàn)，使得我的設(shè)計(jì)得以順利進(jìn)行，并按時(shí)間完成。根據(jù)《高壓成套開(kāi)關(guān)設(shè)備》114頁(yè)，圖所示母線為平放，相間距為300mm，KYN310開(kāi)關(guān)柜的寬度L=1000mm。 熱穩(wěn)定校驗(yàn)導(dǎo)體的最小允許截面應(yīng)小于才能滿足熱穩(wěn)定要求，其由下式確定： （720）式中 C熱穩(wěn)定系數(shù)K集膚效應(yīng)系數(shù)，由《電力工程電氣設(shè)計(jì)手冊(cè)》查得K=；短路電流（kA）；短路等值時(shí)間（S）。 高壓開(kāi)關(guān)柜的選擇6～35KV高壓開(kāi)關(guān)柜主要用于6～35KV的電力系統(tǒng)中，作電能的接受、分配的通、斷和監(jiān)視及保護(hù)之用。 電流互感器的選擇電流互感器的選擇應(yīng)根據(jù)電壓等級(jí)和電流互感器安裝處的最大長(zhǎng)期工作電流進(jìn)行選擇。（2）10KV各出線斷路器的選擇按最大負(fù)荷電流（化工廠）進(jìn)行選擇：查《高壓電器》P306頁(yè),，選擇型斷路器，其技術(shù)數(shù)據(jù)如下表：表75 斷路器參數(shù)表型號(hào)UN kVIN （A）開(kāi)斷電流（kA）開(kāi)斷容量（MVA）極限通過(guò)電流峰值（kA）動(dòng)穩(wěn)定電流（kA）熱穩(wěn)定電流（4S）（kA）固有分閘時(shí)間（S）合閘時(shí)間（S）1063020300505020≤≤所選斷路器技術(shù)數(shù)據(jù)與線路計(jì)算數(shù)據(jù)對(duì)照如下表所示：表76斷路器計(jì)算數(shù)據(jù)比較表計(jì)算數(shù)據(jù)的參數(shù)經(jīng)上表數(shù)據(jù)比較可知，所選型斷路器滿足要求。 根據(jù)系統(tǒng)連接圖畫出等阻抗圖圖61 系統(tǒng)等值阻抗圖 根據(jù)設(shè)計(jì)軟件計(jì)算出各點(diǎn)短路電流由于短路計(jì)算計(jì)算工程復(fù)雜，容易出錯(cuò)，所以在設(shè)計(jì)過(guò)程中通過(guò)計(jì)算機(jī)軟件來(lái)直接得出結(jié)果，既方便又準(zhǔn)確，大大的提高了設(shè)計(jì)質(zhì)量。通過(guò)以上分析比較，可以發(fā)現(xiàn)第一方案以占地面積小、投資少，供電可靠性高為主要優(yōu)點(diǎn)。則補(bǔ)償容量為：無(wú)功補(bǔ)償后系統(tǒng)功率因數(shù)為： 2所以無(wú)功補(bǔ)償合格。綜上所述，本變電所設(shè)計(jì)的主變壓器臺(tái)數(shù)應(yīng)裝設(shè)兩臺(tái)。 熱穩(wěn)定校驗(yàn)溫度修正系數(shù)：校驗(yàn)合格。靈活性：典型設(shè)計(jì)模塊劃分合理，接口靈活，組合方案多樣，增減方便，便于調(diào)整概算，方便使用。 合理設(shè)計(jì)變電站的意義 隨著科學(xué)技術(shù)的發(fā)展，作為現(xiàn)代工業(yè)發(fā)展的基礎(chǔ)和先行官—電力工業(yè)，也隨之有了很大的發(fā)展。水能、煤炭主要分布在西部和北部，能源和電力需求主要集中在東部和中部經(jīng)濟(jì)發(fā)達(dá)地區(qū)。變電所設(shè)計(jì)質(zhì)量的好壞，直接關(guān)系到電力系統(tǒng)的安全、穩(wěn)定、靈活和經(jīng)濟(jì)運(yùn)行，為滿足城鎮(zhèn)負(fù)荷日益增長(zhǎng)的需要，提高對(duì)用戶供電的可靠性和電能質(zhì)量。架空線路要求有較高的機(jī)械性能，耐腐蝕和耐震性能，同時(shí)要考慮經(jīng)濟(jì)性，符合國(guó)家電線產(chǎn)品的標(biāo)準(zhǔn)。即：，校驗(yàn)合格。選擇兩臺(tái)SF9—12500/60型有載調(diào)壓變壓器。第二方案：高壓側(cè)采用單母線分段，低壓側(cè)單母線分段的主接線，如圖52所示。其次還有氣候條件惡化，例如雷擊過(guò)電壓造成的閃絡(luò)放電，由于風(fēng)災(zāi)引起架空線路斷線或?qū)Ь€覆冰引起電桿倒塌等。在高壓電器選擇中的主要問(wèn)題有下述各點(diǎn)：（1）高壓電器應(yīng)滿足正常工作狀態(tài)下的電壓和電流的要求；（2）高壓電器應(yīng)滿足安裝地點(diǎn)和使用的環(huán)境條件要求；（3）高壓電器應(yīng)滿足在短路條件下的熱穩(wěn)定和動(dòng)穩(wěn)定要求；（4）高壓電器應(yīng)考慮操作的頻繁程度和開(kāi)斷負(fù)荷的性質(zhì)；（5）對(duì)于電流互感器的選擇應(yīng)計(jì)及其負(fù)載和準(zhǔn)確度級(jí)別；（6）同類產(chǎn)品應(yīng)盡量減少品種。 互感器的選擇電壓互感器的選擇是根據(jù)額定電壓、裝置種類、構(gòu)造形式、準(zhǔn)確度級(jí)以及按副邊負(fù)載選擇。 10KV側(cè)電流互感器的選擇（1）10KV側(cè)電流互感器根據(jù)安裝地點(diǎn)的最大長(zhǎng)期工作電流和進(jìn)行選擇，經(jīng)查《電力工程電氣設(shè)備手冊(cè)》，524頁(yè)，表3124和532頁(yè)，表3129，選用型電流互感器用于變壓器和母聯(lián)回路，其額定電流比為。10KV側(cè)的所有出線架空線選用一個(gè)型號(hào)的開(kāi)關(guān)柜。按照母線在支持絕緣子上固定的形式，當(dāng)跨數(shù)為2時(shí)，在電動(dòng)力的作用下，母線所受的最大彎矩為： （721）式中 L支持絕緣子間的跨距（m）。在短路電流作用下單位長(zhǎng)度母線所受的最大相間應(yīng)力為：母線所受最大彎矩為：由于母線采用水平放置，其截面系數(shù)為：母線最大相間計(jì)算應(yīng)力為：查《電力工程電氣設(shè)備手冊(cè)》332頁(yè)，表81得硬鋁母線的允許應(yīng)力為所以動(dòng)穩(wěn)定校驗(yàn)合格。參考文獻(xiàn)1 . 水利電力出版社, 19832 . 上海人民出版社, 19933 , 20044 . 遼寧科學(xué)技術(shù)出版社, 19935 （上、下冊(cè)）.中國(guó)水利電力出版社, 19996 . 中國(guó)電力出版社, 20037 . 中國(guó)電力出版社, 20028 賀家李，. 中國(guó)電力出版社, 20039 何仰贊,溫增銀 .電力系統(tǒng)分析. 華中科技大學(xué)出版社, 200110 （上、下冊(cè)）. 中國(guó)電力出版社, 1989 11 . 中國(guó)電力出版社, 199912 , 199713 何仰贊,（上冊(cè)）．華中科技大學(xué)出版社, 200114 . 中國(guó)電力出版社, 199915 , 199416 鄭 . 北京兵器工業(yè)出版社, 199417 and Regression Analysis，wiley，New Yoek，2nd .18 and base model for distribution 19 　Facilities, 198220 ,Understanding Power Quality Problems:Voltage Sags and21 ,NJ:IEEE Press, 1999.22 ,and ,Electrical Power Systems23 Quality. New York:McGrawHill, 199624 :VoltageSagsand25 ,NJ:IEEE Press, 1990附錄A設(shè)備清單序號(hào)名稱型號(hào)數(shù)量（臺(tái)）1主變壓器SF912500/602260kV側(cè)隔離開(kāi)關(guān)GW560G/60010360kV側(cè)斷路器SW263/16003460kV側(cè)電壓互感器JCC5606560kV側(cè)電流互感器LCWD6018660kV側(cè)避雷器FZ606710kV側(cè)接地開(kāi)關(guān)JN41012810kV側(cè)高壓熔斷器RN2104910kV側(cè)進(jìn)線斷路器ZN2810Ⅱ21010kV側(cè)出線斷路器ZN10Ⅰ151110kV側(cè)電壓互感器JSJB1021210kV側(cè)進(jìn)線電流互感器LAJ1061310kV側(cè)出線電流互感器LFZ110321410kV側(cè)避雷器FZ10421510kV側(cè)匯流母線LMY638216補(bǔ)償電容器BWF11/2001W2417高壓開(kāi)關(guān)柜KYN3102318所用變SL710/30kVA2附錄B：外文資料翻譯1原文TRANSFORMER1. INTRODUCTIONThe highvoltage transmission was need for the case electrical power is to be provided at considerable distance from a ge