【正文】 and secondary sides are equal。因?yàn)樽罱K的負(fù)荷，在一些點(diǎn)高電壓必須降低。兩個(gè)線圈之所以相互耦合，是因?yàn)樗鼈冞B接著共同的磁通。從交流電源流入電流的一側(cè)被稱為變壓器的一次側(cè)繞組或者是原邊。變壓器在原邊接收電能的同時(shí)也在向副邊所帶的負(fù)荷輸送電能。這個(gè)空載電流有兩項(xiàng)功能：（1）在鐵芯中產(chǎn)生電磁通，該磁通在零和φm之間做正弦變化，φm是鐵芯磁通的最大值；（2）它的一個(gè)分量說(shuō)明了鐵芯中的渦流和磁滯損耗。顯然可見(jiàn)電流分量Im= I0sinθ0，被稱做勵(lì)磁電流，它在相位上滯后于原邊電壓VP 90186。兩個(gè)相量的分量和代表空載電流，即I0 = Im+ Ie應(yīng)注意的是空載電流是畸變和非正弦形的。相同的磁通會(huì)通過(guò)原邊自身，產(chǎn)生一個(gè)電動(dòng)勢(shì)Ep。因?yàn)闆](méi)有電流流過(guò)二次側(cè)繞組，Es=Vs。產(chǎn)生電壓的平均值如下Eavg = turns即是法拉第定律在瞬時(shí)時(shí)間里的應(yīng)用。一次側(cè)和二次側(cè)電壓增長(zhǎng)的比率稱做變比。在上面公式中一次側(cè)和二次側(cè)的功率因素是相等的；因此VpIp = VsIs從上式我們可以得知 = ≌ ≌ a它表明端電壓比等于匝數(shù)比，換句話說(shuō)，一次側(cè)和二次側(cè)電流比與匝數(shù)比成反比。實(shí)際上, 變比從標(biāo)識(shí)牌數(shù)據(jù)獲得, 列出在滿載情況下原邊和副邊電壓。當(dāng)a=1時(shí)，變壓器的二次側(cè)電壓就等于起一次側(cè)電壓。如果這個(gè)電壓是升高的，它就是一個(gè)升壓變壓器。為了計(jì)算電壓，我們需要更多數(shù)據(jù)。實(shí)際上我們是考慮一臺(tái)理想狀態(tài)下的變壓器；這意味著它沒(méi)有任何損耗。從交流電原理可知，有效值是一個(gè)正弦波，；因此E = 因?yàn)橐淮蝹?cè)繞組和二次側(cè)繞組的磁通相等，所以繞組中每匝的電壓也相同。因此原邊電壓很小，并且Vp的值近乎等于Ep。因此，它于施加的電壓有180186。如果假定變壓器中沒(méi)有其他的電能損耗一次側(cè)的感應(yīng)電動(dòng)勢(shì)Ep和二次側(cè)的感應(yīng)電壓Es可以表示出來(lái)。第二個(gè)分量Ie=I0sinθ0，與原邊電壓同相。變壓器空載電流Iθ一般大約只有滿載電流的2%—5%。3. 變壓器的工作原理當(dāng)二次側(cè)電路開(kāi)路是，即使原邊被施以正弦電壓Vp，也是沒(méi)有能量轉(zhuǎn)移的。磁通連接的第二個(gè)繞組被稱為變壓器的二次側(cè)繞組或者是副邊。變壓器是高效率的，因?yàn)樗鼪](méi)有旋轉(zhuǎn)損失，因此在電壓等級(jí)轉(zhuǎn)換的過(guò)程中，能量損失比較少。本文我們討論的原則和電力變壓器的應(yīng)用。 the marked terminals have the same polarity. Thus when a load is connected to the secondary, the instantaneous load current is in the direction shown. In other words, the polarity markings signify that when positive current enters both windings at the marked terminals, the MMFs of the two windings add.Since the secondary voltage depends on the core flux φ0, it must be clear that the flux should not change appreciably if Es is to remain essentially constant under normal loading conditions. With the load connected, a current Is will flow in the secondary circuit, because the induced EMF Es will act as a voltage source. The secondary current produces an MMF NsIs that creates a flux. This flux has such a direction that at any instant in time it opposes the main flux that created it in the first place. Of course, this is Lenz’s law in action. Thus the MMF represented by NsIs tends to reduce the core flux φ0. This means that the flux linking the primary winding reduces and consequently the primary induced voltage Ep, This reduction in induced voltage causes a greater difference between the impressed voltage and the counter induced EMF, thereby allowing more current to flow in the primary. The fact that primary current Ip increases means that the two conditions stated earlier are fulfilled: (1) the power input increases to match the power output, and (2) the primary MMF increases to offset the tendency of the secondary MMF to reduce the flux.In general, it will be found that the transformer reacts almost instantaneously to keep the resultant core flux essentially constant. Moreover, the core flux φ0 drops very slightly between n o load and full load (about 1 to 3%), a necessary condition if Ep is to fall sufficiently to allow an increase in Ip.On the primary side, Ip’ is the current that flows in the primary to balance the demagnetizing effect of Is. Its MMF NpIp’ sets up a flux linking the primary only. Since the core flux φ0 remains constant. I0 must be the same current that energizes the transformer at no load. The primary current Ip is therefore the sum of the current Ip’ and I0.Because the noload current is relatively small, it is correct to assume that the primary ampereturns equal the secondary ampereturns, since it is under this condition that the core flux is essentially constant. Thus we will assume that I0 is negligible, as it is only a small ponent of the fullload current.When a current flows in the secondary winding, the resulting MMF (NsIs) creates a separate flux, apart from the flux φ0 produced by I0, which links the secondary winding only. This flux does no link with the primary winding and is therefore not a mutual flux.In addition, the load current that flows through the primary winding creates a flux that links with the primary winding only。 thus the induced quantities Ep and Es vary as a sine function. The average value of the induced voltage given byEavg = turnswhich is Faraday’s law applied to a finite time interval. It follows thatEavg = N = 4fNφmwhich N is the number of turns on the winding. Form ac circuit theory, the effective or rootmeansquare (rms) voltage for a sine wave is times the average voltage。 in phase behind the primary voltage VP. It is this ponent that sets up the flux in the core。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 generating station. At some point this high voltage must be reduced, because ultimately is must supply a load. The transformer makes it possible for various parts of a power system to operate at different voltage levels. In this paper we discuss power transformer principles and applications.2. TWOWINDING TRANSFORMERSA transformer i