【正文】 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。the difference between a potential transformer and a power transformer is that the potential transformer is designed to handle only a very small second type of special transformer is a device designed to provide a secondary smaller than but directly proportional to its primary device is called a current transformer.Cirtcuit BreakersA circuit breaker is mechanical switching device capable of making,and breaking currents under normal circuit conditions and also for a specified time ,and mediujm in which circuit interruption is performed may be designated by a suitable prefix, for example,airblastcircuit breaker,oil circuit circuit breakers currently in use can be dlassified into the following categories according to the arcquenching principles:air swetches oel ciryit breakers,minmumoil circuit breakers,airblast circuit breakers,the magenetic air circuit breakers,minimumoilcircuit breakers,aerblast circuit breakers,the by voltage,insulation levelcurrent,interrupting capabilities,transient recovery coltage,interrupting tiome,and trip nameplate on a circuit breaker usually indicates: maximum steadystate current it can carry, 2. The maximum interrupting current,3. The maximum line voltage, interrupting time in cycles, The interrupting time in may last form 3 to 8 cycles on a 60 Hz system. To interrubt large currents quickly, we have to ensure rapid cooling. Highspeed interruption lunits the damage transmission lines and equipment and, equally important,it helps to mainmain the stability of the system whenever a contingency occurs. The main parts of a circuit breaker are usually:arcquenching chamber (or interrupter with moving and fixed contacts) operating mechanism and supporting structures. Air SwitchesWith increasing currents and voltages, springaction driving mechanisms were developed to reduce contact buring by fasteropening ,main contacts were fitted with arcing contacts of special material and shape,which opend after and closed before the main improvements of the air switch were the burshtype contact with a wiping and cleaning function,the insulating barrier leading to arc chutes,and blowout coils with excellent arcextinguishing features,as well as the horn gap contact,are still in use in low voltage as and de breakers. Oil Circuit Breaker Around 1900, in order to cope with the new requirement for “interrupting capacity”,AC switches were immersed in a tank of oil. Is very effective in quenching the arc and establishing the open break after current grids,oilblast features,pressuretight joints and vents,new operating mechanisims,and multiple interrupter were introucedover several decades to make the oil circuit breaker a reliable apparatus for system voltage up to 362kV變壓器變壓器的類型和結(jié)構(gòu)變壓器是一個(gè)通過(guò)磁場(chǎng)作用將一個(gè)交流電壓值變成另一個(gè)電壓值的設(shè)備。它由兩條或更多的金屬絲纏繞在一個(gè)核心磁鐵上組成的。這些繞線（一般）不直接接觸。繞線之間唯一的聯(lián)系是它們共有的存在于磁芯的磁通量。一組變壓器繞組連接到一個(gè)交流電源上，同時(shí)第二組（或許第三組）變壓器繞組作為電源提供給負(fù)載。連接到電源上的變壓器繞組叫做一次繞組，或者輸入繞組。連接負(fù)載的繞組叫做二次繞組或者輸出繞組。如果變壓器上有第三繞組，它叫做三次繞組。電力變壓器由一兩種磁芯中的一種構(gòu)成。一種構(gòu)造是由一種簡(jiǎn)單的變壓器繞組纏繞在矩形兩邊的矩形薄鋼片組成。這種構(gòu)造類型被認(rèn)為是核心形式。另一種類型是由繞組纏繞在中心引腳的疊片鐵心構(gòu)成。這種構(gòu)造類型貝殼形式。其中任意一種類型，磁心都是由排列整齊的彼此之間電氣隔離的薄鐵片構(gòu)成，以便將渦流減小到最小值。一個(gè)物理變壓器的一次繞組和二次繞組被纏繞成一個(gè)在內(nèi)部的另一個(gè)低壓繞組的上面。這樣安排達(dá)到了兩個(gè)目的：。，它導(dǎo)致更少的漏通量。電力變壓器被賦予了很多不同的名字，取決于它們?cè)诋?dāng)前系統(tǒng)中的作用。一變壓器連接到一個(gè)發(fā)電機(jī)的輸出端，并且用于步調(diào)它的電壓達(dá)到變壓器值有時(shí)被叫做單位變壓器。變壓器一個(gè)排在另一個(gè)后面——將電壓從傳送值步降到分布值，被叫做變電站。最后，變壓器將分布電壓和步幅降到最后的實(shí)際使用的電能被叫做發(fā)送變壓器。所有這些設(shè)備本質(zhì)上都是相同的——它們之間唯一不同的是它們的特定用途。斷路器空氣壓縮斷路器是一種機(jī)械開(kāi)關(guān)設(shè)備，能夠在正常和特殊情況下開(kāi)斷電流（比如說(shuō)短路電流）。例如空氣斷路器、油斷路器，干擾電路的導(dǎo)體因該安全可靠的應(yīng)用于其中，電流斷路器按滅弧遠(yuǎn)離通常被分為如下等級(jí)：空氣開(kāi)關(guān)斷路器、油斷路器、少油斷路器、壓縮空氣斷路器、具有消磁性質(zhì)的隔離開(kāi)關(guān)、六氟化硫斷路器和真空斷路器。他們的參數(shù)有電壓等級(jí)、絕緣等級(jí)、電流開(kāi)斷容量、開(kāi)斷時(shí)間的瞬時(shí)電壓恢復(fù)和條炸事件。斷路器的銘牌通常包括：；；；。在60HZ的系統(tǒng)中，中斷可能持續(xù)3至8個(gè)周期，為了快速中斷達(dá)負(fù)荷電流，我們不得不確保它的持續(xù)冷卻，、高速開(kāi)斷能限制對(duì)傳輸線路的損害，這一點(diǎn)是同等重要的它幫助系統(tǒng)在任何事故發(fā)生時(shí)維持穩(wěn)定運(yùn)行，斷路器主要由操作機(jī)構(gòu)、執(zhí)行機(jī)構(gòu)和滅弧室組成。當(dāng)有觸發(fā)電流或者電壓時(shí)，空氣隔離開(kāi)關(guān)的彈簧操作機(jī)構(gòu)迅速動(dòng)作以用來(lái)減少觸點(diǎn)的燒損，主觸點(diǎn)的特殊形狀和使用材料完全適合電弧的接觸，空氣隔離開(kāi)關(guān)更進(jìn)一步的改進(jìn)是由于滅弧的性能、絕緣隔板組成的滅弧罩、帶滅弧功能的觸頭等這些特殊性質(zhì)，所以仍被應(yīng)用于低電壓等級(jí)和直流斷路器中。多油斷路器出現(xiàn)于1900前后，主要用來(lái)滿足新的開(kāi)斷容量的要求，交流開(kāi)關(guān)被浸入一個(gè)油缸之中，油在熄滅電弧和在電流過(guò)零時(shí)建立開(kāi)斷功能是十分有效，滅弧柵、噴油嘴、新的操作機(jī)構(gòu)和多種新的斷路功能在近幾十年引進(jìn)使用多油斷路器能夠適應(yīng)362kV。附錄Ⅱ10kV側(cè)電氣主接線圖變壓器繼電保護(hù)圖