現代電(dian)力系(xi)統普(pu)遍采(cai)用三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)制，因此(ci)需要解(jie)決三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)電(dian)路(lu)中的變(bian)壓(ya)問題。改變(bian)三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)交(jiao)流電(dian)壓(ya)的變(bian)法(fa)有兩種(zhong)：一種(zhong)是(shi)用三(san)(san)(san)臺單(dan)相(xiang)(xiang)(xiang)(xiang)變(bian)壓(ya)器(qi)(qi)組成的三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)變(bian)壓(ya)器(qi)(qi)組；另(ling)外一種(zhong)是(shi)采(cai)用三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)共有整體鐵芯的三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)變(bian)壓(ya)器(qi)(qi)。本節介紹三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)變(bian)壓(ya)器(qi)(qi)的構(gou)造(zao)，下(xia)節課還會介紹三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)變(bian)壓(ya)器(qi)(qi)繞組的連接。
變(bian)壓(ya)器的(de)(de)種類很多，他們的(de)(de)構造和運(yun)行性能上都各有自己的(de)(de)特點，但基本結構卻相同。三(san)相電力(li)變(bian)壓(ya)器由下(xia)列主要部件(jian)組成(cheng)：鐵(tie)芯、線(xian)圈、外(wai)殼、和絕緣(yuan)套管，另外(wai)還設有油(you)枕、呼吸器、防爆管、散熱器、溫度(du)計、油(you)位表(biao)、分接頭開關、冷(leng)卻系統、保護裝置等。變(bian)壓(ya)器的(de)(de)鐵(tie)芯和線(xian)圈是變(bian)壓(ya)器的(de)(de)主要部分，稱為變(bian)壓(ya)器的(de)(de)器身(shen)。如(ru)下(xia)右圖所(suo)示(shi)為三(san)相電力(li)變(bian)壓(ya)器外(wai)形。
1鐵芯
變壓(ya)器的鐵(tie)(tie)芯(xin)有芯(xin)柱(zhu)和(he)鐵(tie)(tie)軛(e)兩部分(fen)組(zu)成(cheng)。塑料(liao)模(mo)具線圈(quan)套裝在鐵(tie)(tie)柱(zhu)上，而鐵(tie)(tie)軛(e)則用來是整個磁路(lu)閉合。為了減小鐵(tie)(tie)芯(xin)內的磁滯及渦流損耗，鐵(tie)(tie)芯(xin)常用含硅量(liang)較(jiao)高的、厚度為0.35～0.5毫(hao)米(mi)的硅鋼片(pian)造成(cheng)，片(pian)上涂有絕(jue)緣漆(qi)。
變(bian)壓(ya)器(qi)按線圈(quan)與(yu)鐵芯配置不同，將鐵芯分(fen)為(wei)心(xin)式(shi)(shi)(shi)和殼式(shi)(shi)(shi)兩種。殼式(shi)(shi)(shi)變(bian)壓(ya)器(qi)的(de)鐵芯包在線圈(quan)的(de)外(wai)部，心(xin)式(shi)(shi)(shi)變(bian)壓(ya)器(qi)線圈(quan)包在鐵芯外(wai)部。殼式(shi)(shi)(shi)變(bian)壓(ya)器(qi)的(de)導熱性能較(jiao)好，機械強(qiang)度較(jiao)高，但(dan)制造工藝復雜，除(chu)了很(hen)小的(de)電(dian)源變(bian)壓(ya)器(qi)外(wai)，目前(qian)已(yi)很(hen)少使(shi)用。心(xin)式(shi)(shi)(shi)變(bian)壓(ya)器(qi)的(de)制造工藝較(jiao)為(wei)簡(jian)單，所以被廣泛(fan)使(shi)用。
線圈的組成
變壓(ya)(ya)器(qi)(qi)的(de)(de)(de)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)是用絕緣(yuan)銅線(xian)(xian)(xian)(xian)(xian)(xian)(xian)或鋁線(xian)(xian)(xian)(xian)(xian)(xian)(xian)繞(rao)成(cheng)的(de)(de)(de)。每臺變壓(ya)(ya)器(qi)(qi)中(zhong)，凡接到電源端(duan)吸取電能(neng)的(de)(de)(de)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)叫做(zuo)初級線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)，也(ye)叫一次(ci)側(ce)(ce)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)或原邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)；輸出電能(neng)端(duan)的(de)(de)(de)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)叫做(zuo)次(ci)級線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)，也(ye)叫二次(ci)側(ce)(ce)或副(fu)(fu)邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)。有(you)時，又將這(zhe)變壓(ya)(ya)器(qi)(qi)中(zhong)接到電壓(ya)(ya)等級高(gao)(gao)的(de)(de)(de)一側(ce)(ce)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)叫做(zuo)高(gao)(gao)壓(ya)(ya)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)；接到較(jiao)低(di)(di)電壓(ya)(ya)一側(ce)(ce)的(de)(de)(de)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)為低(di)(di)壓(ya)(ya)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)。按照(zhao)原、副(fu)(fu)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)在鐵芯(xin)中(zhong)布置方(fang)式不同(tong)(tong)，變壓(ya)(ya)器(qi)(qi)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)結(jie)構(gou)有(you)同(tong)(tong)心(xin)式和交(jiao)疊式兩種。大(da)多(duo)數(shu)電力變壓(ya)(ya)器(qi)(qi)都采用同(tong)(tong)心(xin)式線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)，即(ji)它的(de)(de)(de)原、副(fu)(fu)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)是同(tong)(tong)心(xin)地套裝在同(tong)(tong)一鐵芯(xin)上(shang)。同(tong)(tong)心(xin)式線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)結(jie)構(gou)簡單，制造方(fang)便。交(jiao)疊式線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)的(de)(de)(de)高(gao)(gao)、低(di)(di)壓(ya)(ya)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)是交(jiao)替的(de)(de)(de)套在鐵芯(xin)上(shang)。交(jiao)疊式線(xian)(xian)(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)(quan)的(de)(de)(de)主要優點是機(ji)械強度好，引線(xian)(xian)(xian)(xian)(xian)(xian)(xian)方(fang)便，單絕緣(yuan)比較(jiao)復(fu)雜，所以一般(ban)用于(yu)低(di)(di)電壓(ya)(ya)、大(da)電流的(de)(de)(de)變壓(ya)(ya)器(qi)(qi)上(shang)，如電爐變壓(ya)(ya)器(qi)(qi)、電焊變壓(ya)(ya)器(qi)(qi)等。
2 外(wai)殼
變(bian)(bian)壓(ya)器(qi)的(de)(de)外殼通常用鋼(gang)板焊(han)接而成(cheng)。變(bian)(bian)壓(ya)器(qi)的(de)(de)器(qi)身放(fang)在油箱(xiang)(xiang)內，箱(xiang)(xiang)內灌滿變(bian)(bian)壓(ya)器(qi)油。變(bian)(bian)壓(ya)器(qi)油具(ju)有(you)絕(jue)緣、散熱(re)兩種作用。變(bian)(bian)壓(ya)器(qi)在運行過程中，其鐵芯會產(chan)(chan)生(sheng)渦流及磁(ci)滯損(sun)耗(hao)(hao)；由于(yu)變(bian)(bian)壓(ya)器(qi)線圈具(ju)有(you)一定(ding)的(de)(de)直流電阻，因而會產(chan)(chan)生(sheng)一定(ding)的(de)(de)功率損(sun)耗(hao)(hao)，所有(you)這(zhe)些損(sun)耗(hao)(hao)終都形成(cheng)熱(re)量(liang)。變(bian)(bian)壓(ya)器(qi)油把這(zhe)些熱(re)量(liang)傳到箱(xiang)(xiang)壁，箱(xiang)(xiang)壁上(shang)根據變(bian)(bian)壓(ya)器(qi)容量(liang)不同安裝散熱(re)排管把熱(re)量(liang)散到周圍(wei)空氣中去。
絕緣套管
絕緣套管(guan)是電力(li)變(bian)壓(ya)(ya)器(qi)高、低壓(ya)(ya)線(xian)圈與外線(xian)路(lu)的(de)(de)連接(jie)部件。將變(bian)壓(ya)(ya)器(qi)高、低壓(ya)(ya)線(xian)圈的(de)(de)引(yin)線(xian)從(cong)油箱內(nei)引(yin)出至(zhi)箱外，并(bing)使引(yin)線(xian)與接(jie)地的(de)(de)油箱絕緣，必(bi)須利用絕緣套管(guan)。套管(guan)不但作為引(yin)線(xian)對地絕緣，而且也擔負著固定引(yin)線(xian)的(de)(de)作用。因此，電力(li)變(bian)壓(ya)(ya)器(qi)的(de)(de)套管(guan)必(bi)須具有規定的(de)(de)電壓(ya)(ya)強(qiang)度和足夠的(de)(de)機械強(qiang)度及良好的(de)(de)熱(re)穩定性。套管(guan)的(de)(de)形(xing)式(shi)很多(duo)，按結構不同(tong)可(ke)分為純瓷(ci)質的(de)(de)，瓷(ci)質充油式(shi)和電容器(qi)式(shi)等。
我國電力變壓(ya)(ya)(ya)(ya)(ya)器的套管(guan)在油箱蓋上排列標志(zhi)和(he)順序是：對三相(xiang)電力變壓(ya)(ya)(ya)(ya)(ya)器從高壓(ya)(ya)(ya)(ya)(ya)側(ce)(ce)看去，由左向右的順序是高壓(ya)(ya)(ya)(ya)(ya)側(ce)(ce)O-A-B-C，低壓(ya)(ya)(ya)(ya)(ya)側(ce)(ce)o-a-b-c。對于(yu)單相(xiang)變壓(ya)(ya)(ya)(ya)(ya)器從高壓(ya)(ya)(ya)(ya)(ya)側(ce)(ce)看，由左向右的順序是高壓(ya)(ya)(ya)(ya)(ya)側(ce)(ce)A-X，低壓(ya)(ya)(ya)(ya)(ya)側(ce)(ce)a-x。
3油枕
又稱儲油(you)器。其作用是當變(bian)壓(ya)器在運行中，油(you)因受(shou)熱而膨(peng)脹劑變(bian)壓(ya)器停止運行或(huo)溫度(du)降低使油(you)冷(leng)縮(suo)時(shi)，始終保(bao)證變(bian)壓(ya)器內部的(de)油(you)是充滿的(de)。同時(shi)也減小(xiao)了變(bian)壓(ya)器與空氣的(de)接觸面，以減輕變(bian)壓(ya)器油(you)受(shou)到(dao)氧化和潮濕的(de)影(ying)響。
為(wei)了(le)觀察油(you)(you)(you)枕的(de)油(you)(you)(you)面，油(you)(you)(you)枕的(de)一端還裝有油(you)(you)(you)位表(biao)，顯示(shi)油(you)(you)(you)的(de)容量。油(you)(you)(you)枕里的(de)油(you)(you)(you)位不得超過和刻(ke)度(du)線。
呼吸器與防爆管
呼(hu)吸器：油枕上有一個呼(hu)吸器，呼(hu)吸管(guan)上端高出油枕部，下(xia)端在油枕外部并裝(zhuang)有玻璃器，內盛干干燥劑，吸收進(jin)入油枕內的空氣(qi)中的水(shui)分(fen)。
防爆(bao)管(guan)：防爆(bao)管(guan)是裝在變(bian)壓(ya)器頂端上一個喇叭形的管(guan)子，管(guan)口(kou)用(yong)膜片封住。其作用(yong)是當(dang)變(bian)壓(ya)器內部發生短路故障，變(bian)壓(ya)器油(you)(you)分解(jie)成大量的氣體引(yin)起油(you)(you)管(guan)壓(ya)力(li)增大時，防爆(bao)管(guan)管(guan)口(kou)膜片先被沖破(po)，油(you)(you)氣體由此噴(pen)出，使油(you)(you)箱內壓(ya)力(li)較小(xiao)，防止郵箱因為壓(ya)力(li)突然增大而變(bian)形或(huo)爆(bao)炸。
聯系我們