變壓器(qi)(qi)（Transformer）是(shi)利用(yong)電(dian)(dian)磁(ci)(ci)感(gan)應的原理來改變交流(liu)電(dian)(dian)壓的裝置，主(zhu)要構件是(shi)初級線(xian)圈、次級線(xian)圈和鐵心（磁(ci)(ci)芯(xin)）。主(zhu)要功(gong)能(neng)有：電(dian)(dian)壓變換(huan)、電(dian)(dian)流(liu)變換(huan)、阻抗(kang)變換(huan)、隔離、穩(wen)壓（磁(ci)(ci)飽和變壓器(qi)(qi)）等(deng)。按用(yong)途可(ke)以分為：配電(dian)(dian)變壓器(qi)(qi)、電(dian)(dian)力(li)變壓器(qi)(qi)、全密封(feng)變壓器(qi)(qi)、組合式(shi)變壓器(qi)(qi)、干式(shi)變壓器(qi)(qi)、油浸(jin)式(shi)變壓器(qi)(qi)、單相變壓器(qi)(qi)、電(dian)(dian)爐變壓器(qi)(qi)、整流(liu)變壓器(qi)(qi)等(deng)。

節能(neng)電(dian)(dian)(dian)(dian)(dian)爐在升溫(wen)過程中發熱(re)體電(dian)(dian)(dian)(dian)(dian)阻的(de)改(gai)變(bian)太大，所以(yi)須要在節能(neng)電(dian)(dian)(dian)(dian)(dian)爐和(he)電(dian)(dian)(dian)(dian)(dian)力(li)網之(zhi)間設備一臺(tai)電(dian)(dian)(dian)(dian)(dian)阻爐變(bian)壓(ya)器，以(yi)降低和(he)調度電(dian)(dian)(dian)(dian)(dian)爐的(de)輸入電(dian)(dian)(dian)(dian)(dian)壓(ya)。電(dian)(dian)(dian)(dian)(dian)爐變(bian)壓(ya)器是用(yong)于高溫(wen)電(dian)(dian)(dian)(dian)(dian)爐和(he)節能(neng)電(dian)(dian)(dian)(dian)(dian)爐供電(dian)(dian)(dian)(dian)(dian)的(de)專用(yong)變(bian)壓(ya)器。

容(rong)量(liang)大(da)(da)，結(jie)構凌亂，技術要求較高。其副邊電(dian)(dian)(dian)(dian)壓(ya)低，個(ge)別從數(shu)(shu)十伏到數(shu)(shu)百伏，并需要能(neng)在較大(da)(da)范(fan)圍內調度；副邊電(dian)(dian)(dian)(dian)流常(chang)常(chang)達數(shu)(shu)千至數(shu)(shu)萬安。別的在鋼鐵練習(xi)中(zhong),電(dian)(dian)(dian)(dian)爐(lu)(lu)變(bian)(bian)壓(ya)器(qi)(qi)是指專為(wei)各種高溫電(dian)(dian)(dian)(dian)爐(lu)(lu)供給(gei)電(dian)(dian)(dian)(dian)源的變(bian)(bian)壓(ya)器(qi)(qi)。工業用電(dian)(dian)(dian)(dian)爐(lu)(lu)變(bian)(bian)壓(ya)器(qi)(qi)大(da)(da)致可分為(wei)3類:電(dian)(dian)(dian)(dian)阻(zu)(zu)爐(lu)(lu)變(bian)(bian)壓(ya)器(qi)(qi)、電(dian)(dian)(dian)(dian)弧爐(lu)(lu)變(bian)(bian)壓(ya)器(qi)(qi)和(he)覺得爐(lu)(lu)變(bian)(bian)壓(ya)器(qi)(qi)。電(dian)(dian)(dian)(dian)阻(zu)(zu)爐(lu)(lu)變(bian)(bian)壓(ya)器(qi)(qi)用于機械零件(jian)加熱(re)(re)、熱(re)(re)處理、粉(fen)末(mo)冶金燒結(jie)、有色(se)金屬(shu)熔煉等的電(dian)(dian)(dian)(dian)阻(zu)(zu)爐(lu)(lu)和(he)鹽浴(yu)爐(lu)(lu)。因為(wei)其發熱(re)(re)體的電(dian)(dian)(dian)(dian)阻(zu)(zu)太小。

變壓器是(shi)變換交(jiao)(jiao)流(liu)電壓、交(jiao)(jiao)變電流(liu)和阻抗的器件(jian)，當初級線圈(quan)中(zhong)(zhong)通有交(jiao)(jiao)流(liu)電流(liu)時，鐵芯(xin)（或(huo)磁芯(xin)）中(zhong)(zhong)便產生交(jiao)(jiao)流(liu)磁通，使次級線圈(quan)中(zhong)(zhong)感應(ying)出(chu)電壓（或(huo)電流(liu)）。

變壓器由(you)鐵芯（或磁(ci)芯）和線(xian)圈(quan)組(zu)(zu)成(cheng)，線(xian)圈(quan)有兩(liang)個(ge)或兩(liang)個(ge)以上的繞組(zu)(zu)，其中接(jie)電源的繞組(zu)(zu)叫初級線(xian)圈(quan)，其余(yu)的繞組(zu)(zu)叫次級線(xian)圈(quan)。