山東聊城變壓器有限公司生產的三相變壓器巡視檢查，三相變壓器運行巡視檢查內容和周期如下:
1、檢查儲油柜和充油絕緣套管內油面的高度和封閉處有無滲漏油現象，以及油標管內的油色。
2、檢查三相變壓器上層油溫。正常時一般應在850C以下，輸電線路將幾萬伏或幾十萬伏的高壓電能輸送到負荷區后，須經降壓三相變壓器將高電壓降低，以適合于用電設備的使用。故在供電系統中需要大量的降壓三相變壓器，將輸電線路輸送的高壓變換成不同等級的電壓，以滿足各類負荷的需要。干式變壓器一(yi)、二(er)次(ci)(ci)側(ce)(ce)繞組(zu)因匝(za)數(shu)不同將導(dao)致一(yi)、二(er)次(ci)(ci)側(ce)(ce)繞組(zu)的(de)(de)電(dian)(dian)壓高(gao)低不等(deng)，匝(za)數(shu)多的(de)(de)一(yi)邊電(dian)(dian)壓高(gao)，匝(za)數(shu)少(shao)的(de)(de)一(yi)邊電(dian)(dian)壓低，這就(jiu)是三(san)相(xiang)(xiang)變(bian)壓器(qi)能(neng)夠(gou)改變(bian)電(dian)(dian)壓的(de)(de)道理。如果忽(hu)略三(san)相(xiang)(xiang)變(bian)壓器(qi)的(de)(de)內損耗，可認為三(san)相(xiang)(xiang)變(bian)壓器(qi)二(er)次(ci)(ci)輸出功(gong)率等(deng)于三(san)相(xiang)(xiang)變(bian)壓器(qi)一(yi)次(ci)(ci)輸入(ru)功(gong)率，即: U1I1=U2I2，式中I1、I2分(fen)別為三(san)相(xiang)(xiang)變(bian)壓器(qi)一(yi)次(ci)(ci)、二(er)次(ci)(ci)電(dian)(dian)流(liu)(liu)(liu)的(de)(de)有(you)效值。由此可見(jian)，三(san)相(xiang)(xiang)變(bian)壓器(qi)一(yi)、二(er)次(ci)(ci)電(dian)(dian)流(liu)(liu)(liu)之比與(yu)一(yi)、二(er)次(ci)(ci)繞組(zu)的(de)(de)匝(za)數(shu)比成反比。即三(san)相(xiang)(xiang)變(bian)壓器(qi)匝(za)數(shu)多的(de)(de)一(yi)側(ce)(ce)電(dian)(dian)流(liu)(liu)(liu)小，匝(za)數(shu)少(shao)的(de)(de)一(yi)側(ce)(ce)電(dian)(dian)流(liu)(liu)(liu)大(da)，也就(jiu)是電(dian)(dian)壓高(gao)的(de)(de)一(yi)側(ce)(ce)電(dian)(dian)流(liu)(liu)(liu)小，電(dian)(dian)壓低的(de)(de)一(yi)側(ce)(ce)電(dian)(dian)流(liu)(liu)(liu)大(da)。

例(li)如:SFZ-10000/110表(biao)示三相(xiang)自(zi)然循環風冷有載調(diao)壓(ya)(ya)(ya)(ya)(ya)(ya)，額(e)(e)(e)定容量為10000kVA，高壓(ya)(ya)(ya)(ya)(ya)(ya)繞(rao)(rao)組(zu)額(e)(e)(e)定電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)1lOkV電(dian)力(li)(li)三相(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)。S9-160/10表(biao)示三相(xiang)油(you)浸(jin)自(zi)憐式(shi)，雙繞(rao)(rao)組(zu)無(wu)(wu)勵(li)(li)磁(ci)調(diao)壓(ya)(ya)(ya)(ya)(ya)(ya)，額(e)(e)(e)定容量l60kVA，高壓(ya)(ya)(ya)(ya)(ya)(ya)側(ce)繞(rao)(rao)組(zu)額(e)(e)(e)定電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)為lOkV電(dian)力(li)(li)三相(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)。SC8-315/10表(biao)示三相(xiang)干式(shi)澆注絕緣，雙繞(rao)(rao)組(zu)無(wu)(wu)勵(li)(li)磁(ci)調(diao)壓(ya)(ya)(ya)(ya)(ya)(ya)，額(e)(e)(e)定容量315kVA，高壓(ya)(ya)(ya)(ya)(ya)(ya)側(ce)繞(rao)(rao)組(zu)額(e)(e)(e)定電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)為lOkV電(dian)力(li)(li)三相(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)。S11-M(R)-100/10表(biao)示三相(xiang)油(you)浸(jin)自(zi)冷式(shi)，雙繞(rao)(rao)組(zu)無(wu)(wu)勵(li)(li)磁(ci)調(diao)壓(ya)(ya)(ya)(ya)(ya)(ya)，卷繞(rao)(rao)式(shi)鐵芯 (圓截面)，密封式(shi)，額(e)(e)(e)定容量l00kVA，高壓(ya)(ya)(ya)(ya)(ya)(ya)側(ce)繞(rao)(rao)組(zu)額(e)(e)(e)定電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)為lOkV電(dian)力(li)(li)三相(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)。

SH15-M-50/10表示(shi)三(san)相(xiang)(xiang)(xiang)油浸自冷式(shi)(shi)(shi)，雙繞(rao)(rao)組(zu)無勵磁調(diao)壓(ya)(ya)(ya)(ya)，非晶態合(he)金鐵芯，密封(feng)式(shi)(shi)(shi)，額(e)定(ding)(ding)容量(liang)(liang)5OkVA，高壓(ya)(ya)(ya)(ya)側繞(rao)(rao)組(zu)額(e)定(ding)(ding)電(dian)壓(ya)(ya)(ya)(ya)為lOkVA的(de)(de)電(dian)力(li)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)(ya)器。電(dian)力(li)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)(ya)器可(ke)以按繞(rao)(rao)組(zu)藕合(he)方(fang)式(shi)(shi)(shi)、相(xiang)(xiang)(xiang)數、冷卻方(fang)式(shi)(shi)(shi)、繞(rao)(rao)組(zu)數、繞(rao)(rao)組(zu)導線材(cai)質(zhi)和調(diao)壓(ya)(ya)(ya)(ya)方(fang)式(shi)(shi)(shi)分類。但是，這(zhe)種分類還不足以表達三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)(ya)器的(de)(de)全部特(te)征，所以在三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)(ya)器型(xing)號中除(chu)要把分類特(te)征表達出來外，還需標記其額(e)定(ding)(ding)容量(liang)(liang)和高壓(ya)(ya)(ya)(ya)繞(rao)(rao)組(zu)額(e)定(ding)(ding)電(dian)壓(ya)(ya)(ya)(ya)等(deng)級。圖2一(yi)5是電(dian)力(li)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)(ya)器型(xing)號的(de)(de)表示(shi)方(fang)式(shi)(shi)(shi)。一(yi)些新型(xing)的(de)(de)特(te)殊結構的(de)(de)配電(dian)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)(ya)器，如非晶態合(he)金鐵芯、卷繞(rao)(rao)式(shi)(shi)(shi)鐵芯和密封(feng)式(shi)(shi)(shi)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)(ya)器，在型(xing)號中分別加以H、R和M表示(shi)。

三相(xiang)變(bian)壓器(qi)(qi)分單相(xiang)和三相(xiang)兩種，一般均制成三相(xiang)三相(xiang)變(bian)壓器(qi)(qi)以直接(jie)滿(man)足輸(shu)配電的要求(qiu)。小型(xing)三相(xiang)變(bian)壓器(qi)(qi)有制成單相(xiang)的，特(te)大型(xing)三相(xiang)變(bian)壓器(qi)(qi)做成單相(xiang)后，組成三相(xiang)三相(xiang)變(bian)壓器(qi)(qi)組，以滿(man)足運輸(shu)的要求(qiu)。

三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)器(qi)的(de)額(e)定(ding)(ding)頻率即(ji)是所設計的(de)運行頻率，我國(guo)為(wei)5OHz。額(e)定(ding)(ding)電(dian)壓(ya)(ya)(ya)是指三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)器(qi)線電(dian)壓(ya)(ya)(ya) (有效值(zhi))，它(ta)應與所連(lian)(lian)接(jie)的(de)輸(shu)變(bian)電(dian)線路(lu)(lu)(lu)電(dian)壓(ya)(ya)(ya)相(xiang)(xiang)(xiang)符(fu)合。我國(guo)輸(shu)變(bian)電(dian)線路(lu)(lu)(lu)的(de)電(dian)壓(ya)(ya)(ya)等(deng)級 (即(ji)線路(lu)(lu)(lu)終端(duan)(duan)電(dian)壓(ya)(ya)(ya))為(wei)0.38、(3、6)、10、35、(63)、110、220、330、500(kV)。故連(lian)(lian)接(jie)于線路(lu)(lu)(lu)終端(duan)(duan)的(de)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)器(qi) (稱為(wei)降壓(ya)(ya)(ya)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)(ya)器(qi))其(qi)一次(ci)側額(e)定(ding)(ding)電(dian)壓(ya)(ya)(ya)與上列數值(zhi)相(xiang)(xiang)(xiang)同。

考慮線(xian)(xian)路的(de)(de)(de)電(dian)(dian)壓(ya)降(jiang)，線(xian)(xian)路始端 (電(dian)(dian)源端)電(dian)(dian)壓(ya)將高(gao)于(yu)等(deng)(deng)級電(dian)(dian)壓(ya)，35kV以(yi)(yi)下(xia)(xia)的(de)(de)(de)要高(gao)5%，35kV及以(yi)(yi)上的(de)(de)(de)高(gao)10%，即(ji)線(xian)(xian)路始端電(dian)(dian)壓(ya)為0.4、(3.15、6.3)、10.5、38.5(69)、121、242、363、550(kV)。故連接于(yu)線(xian)(xian)路始端的(de)(de)(de)三相(xiang)變壓(ya)器 (即(ji)升壓(ya)三相(xiang)變壓(ya)器)，其二次(ci)側額定電(dian)(dian)壓(ya)與上列(lie)(lie)(lie)數值相(xiang)同。三相(xiang)變壓(ya)器產品系(xi)列(lie)(lie)(lie)是以(yi)(yi)高(gao)壓(ya)的(de)(de)(de)電(dian)(dian)壓(ya)等(deng)(deng)級區分的(de)(de)(de)，為1OkV及以(yi)(yi)下(xia)(xia)，2OkV、35kV、(66kV)、1lOkV系(xi)列(lie)(lie)(lie)和22OkV系(xi)列(lie)(lie)(lie)等(deng)(deng)。

在(zai)三(san)(san)(san)相(xiang)(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)銘牌所規(gui)定(ding)(ding)(ding)的(de)額(e)(e)(e)定(ding)(ding)(ding)狀態下，三(san)(san)(san)相(xiang)(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)二次側的(de)輸出能力(kVA)。對(dui)(dui)于三(san)(san)(san)相(xiang)(xiang)三(san)(san)(san)相(xiang)(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)，額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)是三(san)(san)(san)相(xiang)(xiang)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)之和(he)。三(san)(san)(san)相(xiang)(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)與繞(rao)(rao)組(zu)額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)有所區(qu)別:雙繞(rao)(rao)組(zu)三(san)(san)(san)相(xiang)(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)的(de)額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)即(ji)為(wei)(wei)繞(rao)(rao)組(zu)的(de)額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang);多繞(rao)(rao)組(zu)三(san)(san)(san)相(xiang)(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)應(ying)對(dui)(dui)每個繞(rao)(rao)組(zu)的(de)額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)加(jia)以規(gui)定(ding)(ding)(ding)，其額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)為(wei)(wei)最(zui)大(da)(da)的(de)繞(rao)(rao)組(zu)額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang);當三(san)(san)(san)相(xiang)(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)由冷卻方式而變更時，則(ze)額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)是指最(zui)大(da)(da)的(de)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)。三(san)(san)(san)相(xiang)(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)額(e)(e)(e)定(ding)(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)的(de)大(da)(da)小(xiao)(xiao)與電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)等級(ji)也是密切(qie)相(xiang)(xiang)關的(de)。電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)低、容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)大(da)(da)時電(dian)(dian)流大(da)(da)，損耗增大(da)(da);電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)高、容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)小(xiao)(xiao)時絕緣比例過大(da)(da)，三(san)(san)(san)相(xiang)(xiang)變壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)尺(chi)寸(cun)相(xiang)(xiang)對(dui)(dui)增大(da)(da)。因此，電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)低的(de)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)必(bi)小(xiao)(xiao)，電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)高的(de)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)必(bi)大(da)(da)。

三相(xiang)變(bian)壓器的(de)額定(ding)電(dian)(dian)流為(wei)通(tong)過繞(rao)組線端的(de)電(dian)(dian)流，即為(wei)線電(dian)(dian)流 (有(you)效值)。它的(de)大小等于繞(rao)組的(de)額定(ding)容量除以該繞(rao)組的(de)額定(ding)電(dian)(dian)壓及相(xiang)應的(de)相(xiang)系(xi)數 (單相(xiang)為(wei)l，三相(xiang)為(wei)3)。 

單相三相變壓器額定電流為: 三相三相變壓器繞組為Y連接時，線電流為繞組電流；D連接時線電流等于1.732繞組電流。
三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)器(qi)同(tong)側(ce)繞組(zu)是按一定形(xing)(xing)式連(lian)接(jie)的(de)(de)。三(san)相(xiang)(xiang)(xiang)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)器(qi)或組(zu)成(cheng)三(san)相(xiang)(xiang)(xiang)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)器(qi)組(zu)的(de)(de)單(dan)相(xiang)(xiang)(xiang)三(san)相(xiang)(xiang)(xiang)變(bian)壓(ya)(ya)器(qi)，則可以連(lian)接(jie)為星形(xing)(xing)、三(san)角(jiao)形(xing)(xing)等。星形(xing)(xing)聯(lian)接(jie)是各相(xiang)(xiang)(xiang)線圈的(de)(de)一端接(jie)成(cheng)一個公共點(dian) (中性點(dian))，其余接(jie)端子接(jie)到相(xiang)(xiang)(xiang)應的(de)(de)線端上;三(san)角(jiao)形(xing)(xing)聯(lian)接(jie)是三(san)個相(xiang)(xiang)(xiang)線圈互相(xiang)(xiang)(xiang)串聯(lian)形(xing)(xing)成(cheng)閉合回路，由(you)串聯(lian)處接(jie)至相(xiang)(xiang)(xiang)應的(de)(de)線端。

星(xing)形、三角(jiao)形、曲(qu)折形等聯(lian)接，現在(zai)對于(yu)高(gao)壓(ya)(ya)繞組分(fen)別用(yong)符號(hao)(hao)y、D、Z表(biao)示;對于(yu)中(zhong)壓(ya)(ya)和低壓(ya)(ya)繞組分(fen)別用(yong)符號(hao)(hao)y、d、z表(biao)示。有中(zhong)性點(dian)引出時(shi)則(ze)分(fen)別用(yong)符號(hao)(hao)YN、ZN和yn、zn表(biao)示。三相(xiang)變壓(ya)(ya)器(qi)按(an)高(gao)壓(ya)(ya)、中(zhong)壓(ya)(ya)和低壓(ya)(ya)繞組聯(lian)接的順(shun)序(xu)組合(he)起來就是繞組的聯(lian)接組，例如:三相(xiang)變壓(ya)(ya)器(qi)按(an)高(gao)壓(ya)(ya)為(wei)D、低壓(ya)(ya)為(wei)yn聯(lian)接，則(ze)繞組聯(lian)接組為(wei)Dyn(Dyn11);

三相變壓器接在電網上運行時，三相變壓器二次側電壓將由于種種原因發生變化，影響用電設備的工常運行。因此三相變壓器應具備一定的調壓能力。根據三相變壓器的工作原理，當高、低壓繞組的匝數比變化時，三相變壓器二次側電壓也隨之變動，采用改變三相變壓器匝數比即可達到調壓的目的。三相變壓器調壓方式通常分為無勵磁調壓和有載調壓兩種方式。當二次側不帶負載，一次側又與電網斷開時的調壓為無勵磁調壓，在二次側帶負載下的調壓為有載調壓。
　　　　

當三相(xiang)變壓(ya)(ya)器二次(ci)(ci)繞組開路(lu)(lu)，一(yi)次(ci)(ci)繞組施加額定(ding)頻率的(de)(de)額定(ding)電(dian)(dian)(dian)壓(ya)(ya)時(shi)，一(yi)次(ci)(ci)繞組中所(suo)流(liu)過(guo)的(de)(de)電(dian)(dian)(dian)流(liu)稱空(kong)載(zai)(zai)電(dian)(dian)(dian)流(liu)I0, 三相(xiang)變壓(ya)(ya)器空(kong)載(zai)(zai)合閘時(shi)有較大的(de)(de)沖(chong)擊電(dian)(dian)(dian)流(liu)。當三相(xiang)變壓(ya)(ya)器二次(ci)(ci)側短(duan)路(lu)(lu)，一(yi)次(ci)(ci)側施加電(dian)(dian)(dian)壓(ya)(ya)使其電(dian)(dian)(dian)流(liu)達(da)到額定(ding)值，此時(shi)所(suo)施加的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)稱為(wei)阻抗(kang)電(dian)(dian)(dian)壓(ya)(ya)UZ，三相(xiang)變壓(ya)(ya)器從(cong)電(dian)(dian)(dian)源吸取的(de)(de)功率即為(wei)短(duan)路(lu)(lu)損耗。以阻抗(kang)電(dian)(dian)(dian)壓(ya)(ya)與額定(ding)電(dian)(dian)(dian)壓(ya)(ya)UN之(zhi)比的(de)(de)百分(fen)數表(biao)示。

三(san)(san)相(xiang)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)負(fu)(fu)載(zai)(zai)運(yun)行時，由于三(san)(san)相(xiang)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)內部的(de)(de)阻抗壓(ya)(ya)(ya)(ya)降(jiang)，二(er)次(ci)電(dian)壓(ya)(ya)(ya)(ya)將隨(sui)負(fu)(fu)載(zai)(zai)電(dian)流和負(fu)(fu)載(zai)(zai)功率(lv)因數(shu)的(de)(de)改(gai)(gai)變(bian)(bian)而改(gai)(gai)變(bian)(bian)。電(dian)壓(ya)(ya)(ya)(ya)調整率(lv)即說明三(san)(san)相(xiang)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)二(er)次(ci)電(dian)壓(ya)(ya)(ya)(ya)變(bian)(bian)化(hua)的(de)(de)程度大小(xiao)(xiao)，為衡(heng)量(liang)三(san)(san)相(xiang)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)供電(dian)質量(liang)的(de)(de)數(shu)據，其定(ding)義為:在給定(ding)負(fu)(fu)載(zai)(zai)功率(lv)因數(shu)下(xia) (一(yi)般取0.8)二(er)次(ci)空(kong)載(zai)(zai)電(dian)壓(ya)(ya)(ya)(ya)U2N和二(er)次(ci)負(fu)(fu)載(zai)(zai)電(dian)壓(ya)(ya)(ya)(ya)U2之差(cha)與二(er)次(ci)額定(ding)電(dian)壓(ya)(ya)(ya)(ya)U2N的(de)(de)比(bi)。三(san)(san)相(xiang)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)的(de)(de)效率(lv)η為輸出的(de)(de)有(you)功功率(lv)與輸入(ru)的(de)(de)有(you)功功率(lv)之比(bi)的(de)(de)百分數(shu)。通(tong)常(chang)中小(xiao)(xiao)型三(san)(san)相(xiang)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)的(de)(de)效率(lv)約為90%以上，大型三(san)(san)相(xiang)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)的(de)(de)效率(lv)在95%以上。

三(san)(san)(san)相(xiang)(xiang)變(bian)(bian)壓(ya)(ya)(ya)器(qi)的(de)溫(wen)(wen)(wen)(wen)升(sheng)，對(dui)于(yu)空氣(qi)冷卻(que)(que)三(san)(san)(san)相(xiang)(xiang)變(bian)(bian)壓(ya)(ya)(ya)器(qi)是指(zhi)測(ce)量(liang)(liang)部位的(de)溫(wen)(wen)(wen)(wen)度(du)與冷卻(que)(que)空氣(qi)溫(wen)(wen)(wen)(wen)度(du)之(zhi)(zhi)差(cha);對(dui)于(yu)水冷卻(que)(que)三(san)(san)(san)相(xiang)(xiang)變(bian)(bian)壓(ya)(ya)(ya)器(qi)是指(zhi)測(ce)量(liang)(liang)部位的(de)溫(wen)(wen)(wen)(wen)度(du)與冷卻(que)(que)器(qi)入(ru)口處水溫(wen)(wen)(wen)(wen)之(zhi)(zhi)差(cha)。油浸式(shi)(shi)三(san)(san)(san)相(xiang)(xiang)變(bian)(bian)壓(ya)(ya)(ya)器(qi)繞(rao)(rao)組(zu)(zu)和頂層油溫(wen)(wen)(wen)(wen)升(sheng)限(xian)值:因為(wei)(wei)(wei)A級絕緣在980C時產生的(de)絕緣損(sun)壞(huai)為(wei)(wei)(wei)正(zheng)常(chang)損(sun)壞(huai)，而保(bao)證(zheng)三(san)(san)(san)相(xiang)(xiang)變(bian)(bian)壓(ya)(ya)(ya)器(qi)正(zheng)常(chang)壽命的(de)年平均氣(qi)溫(wen)(wen)(wen)(wen)是2O0C，繞(rao)(rao)組(zu)(zu)最(zui)熱點(dian)與其平均溫(wen)(wen)(wen)(wen)度(du)之(zhi)(zhi)差(cha)為(wei)(wei)(wei)130C，所以繞(rao)(rao)組(zu)(zu)溫(wen)(wen)(wen)(wen)升(sheng)限(xian)值為(wei)(wei)(wei)98-20-13二(er)65K。油正(zheng)常(chang)運行的(de)最(zui)高溫(wen)(wen)(wen)(wen)度(du)為(wei)(wei)(wei)950C，最(zui)高氣(qi)溫(wen)(wen)(wen)(wen)為(wei)(wei)(wei)400C，所以頂層油溫(wen)(wen)(wen)(wen)升(sheng)限(xian)值為(wei)(wei)(wei)95-40=55K。(2)冷卻(que)(que)方(fang)式(shi)(shi)  三(san)(san)(san)相(xiang)(xiang)變(bian)(bian)壓(ya)(ya)(ya)器(qi)的(de)冷卻(que)(que)方(fang)式(shi)(shi)有多種，如(ru)干式(shi)(shi)自冷、油浸風冷等，各種方(fang)式(shi)(shi)適用于(yu)不同種類(lei)的(de)三(san)(san)(san)相(xiang)(xiang)變(bian)(bian)壓(ya)(ya)(ya)器(qi)。