試驗變壓器的選擇方法及需要考慮的因素

選擇試驗變壓器時(shi)，主要考慮以下幾(ji)個方面：

??1)試(shi)(shi)驗(yan)(yan)電(dian)壓(ya)。依據試(shi)(shi)品的(de)要求，首先(xian)選用(yong)具(ju)有(you)合適電(dian)壓(ya)的(de)試(shi)(shi)驗(yan)(yan)變(bian)壓(ya)器(qi)，使試(shi)(shi)驗(yan)(yan)變(bian)壓(ya)器(qi)的(de)高(gao)壓(ya)側(ce)(ce)額定電(dian)壓(ya)Un高(gao)于被(bei)試(shi)(shi)品的(de)試(shi)(shi)驗(yan)(yan)電(dian)壓(ya)Us，即Un>Us。其次(ci)應檢查(cha)試(shi)(shi)驗(yan)(yan)變(bian)壓(ya)器(qi)所需(xu)的(de)低(di)壓(ya)側(ce)(ce)電(dian)壓(ya)，是(shi)否能和現場(chang)電(dian)源電(dian)壓(ya)，調壓(ya)器(qi)相(xiang)匹配。

??2)試(shi)驗(yan)電流。試(shi)驗(yan)變壓器的額定輸出(chu)電流In應大于被(bei)試(shi)品所需的電流Is，即(ji)In>Is。被(bei)試(shi)品所需的電流可按其電容(rong)(rong)估算，Is=UswCx，其中Cx包括試(shi)品電容(rong)(rong)和附加電容(rong)(rong)。

??3)試驗容量。根據試驗變(bian)壓(ya)器輸出(chu)的(de)額定(ding)電(dian)流及額定(ding)電(dian)壓(ya)，便(bian)可(ke)確定(ding)試驗變(bian)壓(ya)器的(de)容量，即P=UnIn。

??根據相關試驗變壓器的標準規定，我國試驗變壓器的電壓等級有：5、10、25、35、50、100、150、300kV等;容量等級有：3、5、10、25、50、100、150、200kVA等。

??由(you)計算(suan)結(jie)果，相關標(biao)準即可選出(chu)所需要的試(shi)驗(yan)變壓器(qi)。如有特(te)殊(shu)要求，可向制造廠武漢市合(he)眾電(dian)氣訂購特(te)殊(shu)規格的試(shi)驗(yan)變壓器(qi)用于試(shi)驗(yan)。

??試驗變壓器選擇(ze)實(shi)例

??例如配電(dian)(dian)(dian)變壓(ya)器(qi)(qi)的(de)(de)(de)電(dian)(dian)(dian)壓(ya)等級(ji)和容量是10kV、1000kVA，試(shi)(shi)品又基本(ben)上是10kV的(de)(de)(de)，就可選擇50kV、5kVA的(de)(de)(de)試(shi)(shi)驗(yan)(yan)變壓(ya)器(qi)(qi)，因為(wei)10kV、1000kVA的(de)(de)(de)配電(dian)(dian)(dian)變壓(ya)器(qi)(qi)的(de)(de)(de)山廠試(shi)(shi)驗(yan)(yan)電(dian)(dian)(dian)壓(ya)為(wei)35kV，交流試(shi)(shi)驗(yan)(yan)電(dian)(dian)(dian)壓(ya)為(wei)30kV;同(tong)時又可滿足10kV絕緣(yuan)子以及高壓(ya)開關柜的(de)(de)(de)試(shi)(shi)驗(yan)(yan)(試(shi)(shi)驗(yan)(yan)電(dian)(dian)(dian)壓(ya)為(wei)42kV)和10kV電(dian)(dian)(dian)纜的(de)(de)(de)直流試(shi)(shi)驗(yan)(yan)(直流電(dian)(dian)(dian)壓(ya)為(wei)60kV，對應的(de)(de)(de)交流電(dian)(dian)(dian)壓(ya)為(wei)42.83kV)的(de)(de)(de)要求。

??在試驗(yan)(yan)(yan)容(rong)(rong)(rong)量(liang)(liang)方(fang)面，一臺(tai)10kV、1000kVA的被試變(bian)壓(ya)器(qi)(qi)，其充電(dian)(dian)時(shi)的電(dian)(dian)容(rong)(rong)(rong)電(dian)(dian)流(liu)在30~35kV試驗(yan)(yan)(yan)吋約為(wei)(wei)(wei)80~110mA，因為(wei)(wei)(wei)35kVx110mA<5kVA，因此(ci)(ci)5kVA能滿(man)足要求(qiu)。又如(ru)一臺(tai)35kV、2000~4000kVA的變(bian)壓(ya)器(qi)(qi)，當(dang)試驗(yan)(yan)(yan)電(dian)(dian)壓(ya)在72~85kV時(shi)的電(dian)(dian)容(rong)(rong)(rong)電(dian)(dian)流(liu)約為(wei)(wei)(wei)150~260mA，6000~8000kVA的約為(wei)(wei)(wei)300~420mA，10000kVA的約為(wei)(wei)(wei)800~1000mA等，此(ci)(ci)時(shi)所選(xuan)試驗(yan)(yan)(yan)變(bian)壓(ya)器(qi)(qi)的容(rong)(rong)(rong)量(liang)(liang)必須(xu)大于上述試品電(dian)(dian)容(rong)(rong)(rong)電(dian)(dian)流(liu)所對(dui)應(ying)的容(rong)(rong)(rong)量(liang)(liang)。常規試驗(yan)(yan)(yan)需求(qiu)，試驗(yan)(yan)(yan)變(bian)壓(ya)器(qi)(qi)容(rong)(rong)(rong)量(liang)(liang)為(wei)(wei)(wei)被試品(電(dian)(dian)力(li)變(bian)壓(ya)器(qi)(qi))容(rong)(rong)(rong)量(liang)(liang)的5%o