電(dian)(dian)磁(ci)式電(dian)(dian)壓(ya)(ya)互(hu)感(gan)器(qi)與電(dian)(dian)容式電(dian)(dian)壓(ya)(ya)互(hu)感(gan)器(qi)的差異與特(te)征，信(xin)任許多人都(dou)不是(shi)很清(qing)楚，現(xian)在就選(xuan)用35kv母線的電磁式電壓互感器與選(xuan)用200kv母線的電(dian)(dian)容(rong)式電(dian)(dian)壓互(hu)感器做一個詳細(xi)的解(jie)說。
電(dian)(dian)磁式(shi)電(dian)(dian)壓(ya)(ya)(ya)互感(gan)(gan)器(qi)，它與(yu)電(dian)(dian)力(li)變壓(ya)(ya)(ya)器(qi)相似。電(dian)(dian)磁式(shi)電(dian)(dian)壓(ya)(ya)(ya)互感(gan)(gan)器(qi)工作原理(li)的(de)(de)(de)(de)特征是：電(dian)(dian)磁式(shi)電(dian)(dian)壓(ya)(ya)(ya)互感(gan)(gan)器(qi)的(de)(de)(de)(de)一次(ci)(ci)(ci)(ci)(ci)繞(rao)組(zu)(zu)直接并聯于(yu)一次(ci)(ci)(ci)(ci)(ci)回路中，一次(ci)(ci)(ci)(ci)(ci)繞(rao)組(zu)(zu)上(shang)的(de)(de)(de)(de)電(dian)(dian)壓(ya)(ya)(ya)取(qu)決于(yu)一次(ci)(ci)(ci)(ci)(ci)回路上(shang)的(de)(de)(de)(de)電(dian)(dian)壓(ya)(ya)(ya)，二(er)(er)次(ci)(ci)(ci)(ci)(ci)繞(rao)組(zu)(zu)與(yu)一次(ci)(ci)(ci)(ci)(ci)繞(rao)組(zu)(zu)無電(dian)(dian)的(de)(de)(de)(de)耦合，是經過磁耦合。二(er)(er)次(ci)(ci)(ci)(ci)(ci)繞(rao)組(zu)(zu)通常(chang)接的(de)(de)(de)(de)是一些(xie)外表、儀器(qi)及(ji)維護設備容量一般均在(zai)幾十至幾百(bai)伏安，所以(yi)負載很(hen)小，而且是恒定的(de)(de)(de)(de)，所以(yi)電(dian)(dian)壓(ya)(ya)(ya)互感(gan)(gan)器(qi)的(de)(de)(de)(de)一次(ci)(ci)(ci)(ci)(ci)側(ce)可(ke)視為(wei)一個電(dian)(dian)壓(ya)(ya)(ya)源，根(gen)本不(bu)受二(er)(er)次(ci)(ci)(ci)(ci)(ci)負載的(de)(de)(de)(de)影響。正常(chang)運轉時，電(dian)(dian)壓(ya)(ya)(ya)互感(gan)(gan)器(qi)二(er)(er)次(ci)(ci)(ci)(ci)(ci)側(ce)由于(yu)負載較小，根(gen)本處于(yu)開路狀況，電(dian)(dian)壓(ya)(ya)(ya)互感(gan)(gan)器(qi)二(er)(er)次(ci)(ci)(ci)(ci)(ci)電(dian)(dian)壓(ya)(ya)(ya)根(gen)本等于(yu)二(er)(er)次(ci)(ci)(ci)(ci)(ci)側(ce)感(gan)(gan)應電(dian)(dian)動勢取(qu)決于(yu)一次(ci)(ci)(ci)(ci)(ci)系統電(dian)(dian)壓(ya)(ya)(ya)。
電(dian)磁式(shi)電(dian)壓互(hu)(hu)感器的(de)(de)分類方法許多(duo)，根(gen)據絕(jue)緣(yuan)介質(zhi)可分為(wei)干式(shi)和油(you)式(shi)；根(gen)據相數的(de)(de)不同可分為(wei)單相、三相兩種；根(gen)據繞(rao)組(zu)(zu)的(de)(de)多(duo)少可分為(wei)雙繞(rao)組(zu)(zu)、三繞(rao)組(zu)(zu)、四(si)繞(rao)組(zu)(zu)三種；按其運(yun)(yun)(yun)轉承受(shou)的(de)(de)電(dian)壓不同，可分為(wei)半絕(jue)緣(yuan)和全絕(jue)緣(yuan)電(dian)壓互(hu)(hu)感器等等。在(zai)實際(ji)運(yun)(yun)(yun)用中一般(ban)運(yun)(yun)(yun)用單相三繞(rao)組(zu)(zu)或四(si)繞(rao)組(zu)(zu)的(de)(de)最多(duo)。
若35kV母(mu)線電(dian)(dian)壓(ya)互(hu)感器(qi)選用的為單相澆注(zhu)絕緣(yuan)的電(dian)(dian)磁(ci)(ci)式電(dian)(dian)壓(ya)互(hu)感器(qi)，電(dian)(dian)磁(ci)(ci)式電(dian)(dian)壓(ya)互(hu)感器(qi)的勵磁(ci)(ci)特(te)性為非線性特(te)性，在35kV的(de)電力系統中性(xing)點偏移(yi)、瞬間電弧接地或(huo)進行(xing)倒閘操作的(de)激發下(xia)，都可能與電力系統散布的(de)電容構成鐵磁(ci)諧振，因而，選用的(de)電磁(ci)式電壓(ya)互感器都選用了消諧辦法。
跟著(zhu)電(dian)力系統輸電(dian)電(dian)壓(ya)的增(zeng)高(gao)，電(dian)磁式電(dian)壓(ya)互感器的體(ti)積越(yue)來(lai)越(yue)大，本錢隨之增(zeng)高(gao)，因(yin)而220kV電(dian)壓等級宜(yi)選(xuan)用(yong)電(dian)容(rong)式(shi)電(dian)壓互感器。根據這(zhe)一要求，我們選(xuan)用(yong)220kV母線電容式(shi)電壓互感器。
電容式的(de)全稱為電容分壓式電壓互感器，工作原理如圖(tu)1。在被測二次(ci)回路與大(da)地間(jian)接(jie)有電容組(zu)，電容組(zu)由C1和C2組成，其間C2兩端并接電(dian)壓互(hu)感器二次負(fu)荷Z2，L為補償電抗器，當電壓互感器空載運轉時U2=U0=C1&TImes;U1/（C1+C2）=ηTVU1。電(dian)壓U2與其一次電壓U1大(da)小成正比(bi)，相(xiang)(xiang)位相(xiang)(xiang)同。當電壓(ya)互感器帶負荷Z2時(shi)，圖2為(wei)等值(zhi)電路圖，其間U0為空載電壓，jwL為補償電抗(kang)器的阻抗(kang)，Z0為電(dian)壓互感器的內阻(zu)抗Z0=1/jw（C1+C2），當jwL=Z0，即1/w（C1+C2）=wL時，Z0+jwL=0，U2=U0=ηTVU1，電壓互(hu)感器二次輸出電壓U2，與其一次側電壓U1大小成正(zheng)比(bi)，相位(wei)相同(tong)。
與電(dian)磁式電(dian)壓互感器(qi)比較，電(dian)容(rong)式電(dian)壓互感器(qi)具有以下特征：
1）除作為電(dian)(dian)壓互感器外，還(huan)可將其分電(dian)(dian)容，高(gao)頻載波通訊(xun)的耦合電(dian)(dian)容。
2）電(dian)容(rong)式(shi)電(dian)壓互感器(qi)的沖擊(ji)絕緣強度比電(dian)磁式(shi)高。
3）體(ti)積小，重量(liang)輕，本錢低，占(zhan)地(di)面積小。
4）誤差特性(xing)和暫態特性(xing)不如電磁式，且輸出容量小。
電磁式(shi)與電容式(shi)電壓互感器的首(shou)要差(cha)異
電(dian)(dian)(dian)(dian)磁(ci)式(shi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)是(shi)(shi)一(yi)種(zhong)經(jing)過電(dian)(dian)(dian)(dian)磁(ci)感(gan)應將一(yi)次電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)按份額變換成二(er)次電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)，種(zhong)互(hu)感(gan)器(qi)(qi)不附加其它改變一(yi)次電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)電(dian)(dian)(dian)(dian)氣元件如(ru)電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)。電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)式(shi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)是(shi)(shi)由串聯電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)抽取(qu)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，再經(jing)變壓(ya)(ya)(ya)(ya)器(qi)(qi)變壓(ya)(ya)(ya)(ya)作為(wei)表計、繼電(dian)(dian)(dian)(dian)維(wei)護等(deng)的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)源(yuan)的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)，電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)式(shi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)還可(ke)以將載波頻(pin)率耦合到輸電(dian)(dian)(dian)(dian)線用于(yu)遠程通訊(xun)、遠方(fang)測量、選擇性的(de)線路(lu)高(gao)頻(pin)維(wei)護、遙控(kong)、電(dian)(dian)(dian)(dian)傳打字等(deng)。因而和慣例(li)的(de)電(dian)(dian)(dian)(dian)磁(ci)式(shi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)比較，電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)式(shi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)器(qi)(qi)除可(ke)防止因電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)鐵(tie)芯飽(bao)滿引起鐵(tie)磁(ci)諧振外，在經(jing)濟和安(an)全上還有許(xu)多優勝之處。
電(dian)容(rong)(rong)式電(dian)壓(ya)互感器(qi)(qi)首要(yao)由(you)電(dian)容(rong)(rong)分(fen)壓(ya)器(qi)(qi)和(he)中壓(ya)變(bian)壓(ya)器(qi)(qi)組成。電(dian)容(rong)(rong)分(fen)壓(ya)器(qi)(qi)由(you)瓷(ci)套(tao)和(he)裝在其間的(de)若干串(chuan)聯電(dian)容(rong)(rong)器(qi)(qi)組成，瓷(ci)套(tao)內充溢堅持0.1MPa正壓(ya)(ya)(ya)的絕(jue)緣(yuan)油，并用鋼制波(bo)紋管平(ping)衡不同環(huan)境(jing)以堅持油壓(ya)(ya)(ya)，電(dian)(dian)(dian)(dian)容(rong)分壓(ya)(ya)(ya)可(ke)用作耦(ou)合(he)電(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)(qi)銜接(jie)載(zai)波(bo)設(she)(she)備(bei)(bei)。中壓(ya)(ya)(ya)變壓(ya)(ya)(ya)器(qi)(qi)(qi)由(you)(you)裝(zhuang)在(zai)密封油箱內(nei)的變壓(ya)(ya)(ya)器(qi)(qi)(qi)，補償電(dian)(dian)(dian)(dian)抗器(qi)(qi)(qi)和阻(zu)(zu)(zu)(zu)(zu)尼設(she)(she)備(bei)(bei)組(zu)成，油箱頂部的空(kong)間充氮(dan)。一(yi)(yi)次(ci)(ci)(ci)繞(rao)組(zu)分為主(zhu)繞(rao)組(zu)和微調(diao)繞(rao)組(zu)，一(yi)(yi)次(ci)(ci)(ci)側和一(yi)(yi)次(ci)(ci)(ci)繞(rao)組(zu)間串聯一(yi)(yi)個低(di)損(sun)耗電(dian)(dian)(dian)(dian)抗器(qi)(qi)(qi)。由(you)(you)于(yu)電(dian)(dian)(dian)(dian)容(rong)式(shi)(shi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)互(hu)感器(qi)(qi)(qi)的非線性阻(zu)(zu)(zu)(zu)(zu)抗和固有的電(dian)(dian)(dian)(dian)容(rong)有時會(hui)在(zai)電(dian)(dian)(dian)(dian)容(rong)式(shi)(shi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)互(hu)感器(qi)(qi)(qi)內(nei)引(yin)起鐵磁(ci)諧(xie)(xie)振，因而用阻(zu)(zu)(zu)(zu)(zu)尼設(she)(she)備(bei)(bei)按捺諧(xie)(xie)振，阻(zu)(zu)(zu)(zu)(zu)尼設(she)(she)備(bei)(bei)由(you)(you)電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)和電(dian)(dian)(dian)(dian)抗器(qi)(qi)(qi)組(zu)成，跨接(jie)在(zai)二次(ci)(ci)(ci)繞(rao)組(zu)上，正常情況下(xia)阻(zu)(zu)(zu)(zu)(zu)尼設(she)(she)備(bei)(bei)有很高的阻(zu)(zu)(zu)(zu)(zu)抗，當鐵磁(ci)諧(xie)(xie)振引(yin)起過電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，在(zai)中壓(ya)(ya)(ya)變壓(ya)(ya)(ya)器(qi)(qi)(qi)受到影響前，電(dian)(dian)(dian)(dian)抗器(qi)(qi)(qi)已(yi)經(jing)飽滿了只剩電(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)負載(zai)，使(shi)振蕩能量很快被(bei)下(xia)降。
