整流變壓器廠家分(fen)析變(bian)壓器(qi)(qi)差(cha)動掩護用(yong)的(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)互(hu)(hu)(hu)感(gan)器(qi)(qi)必(bi)要(yao)滿意(yi)兩個前(qian)提，其(qi)一是穩態(tai)(tai)偏(pian)(pian)(pian)差(cha)必(bi)需(xu)節制在10%偏(pian)(pian)(pian)差(cha)規模(mo)以(yi)內，因為(wei)整定盤算中采(cai)納的(de)(de)不(bu)(bu)(bu)平衡(heng)(heng)穩態(tai)(tai)電(dian)(dian)(dian)(dian)(dian)流(liu)是按10%偏(pian)(pian)(pian)差(cha)前(qian)提盤算。其(qi)二(er)是暫(zan)態(tai)(tai)偏(pian)(pian)(pian)差(cha)，影響電(dian)(dian)(dian)(dian)(dian)流(liu)互(hu)(hu)(hu)感(gan)器(qi)(qi)暫(zan)態(tai)(tai)特性(xing)的(de)(de)參數主(zhu)要(yao)有：短路(lu)(lu)電(dian)(dian)(dian)(dian)(dian)流(liu)及其(qi)非周期重量，一次回路(lu)(lu)光陰(yin)(yin)常數，電(dian)(dian)(dian)(dian)(dian)流(liu)互(hu)(hu)(hu)感(gan)器(qi)(qi)事情輪回及閱歷光陰(yin)(yin)，二(er)次回路(lu)(lu)光陰(yin)(yin)常數等(deng)。電(dian)(dian)(dian)(dian)(dian)流(liu)互(hu)(hu)(hu)感(gan)器(qi)(qi)剩磁對(dui)付(fu)飽(bao)和(he)影響很大(da)，當剩磁與(yu)短路(lu)(lu)電(dian)(dian)(dian)(dian)(dian)流(liu)暫(zan)態(tai)(tai)重量惹起的(de)(de)磁通極性(xing)相同時，減輕二(er)次電(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)畸變(bian)，是以(yi)電(dian)(dian)(dian)(dian)(dian)流(liu)互(hu)(hu)(hu)感(gan)器(qi)(qi)鐵心(xin)中存在剩磁，則電(dian)(dian)(dian)(dian)(dian)流(liu)互(hu)(hu)(hu)感(gan)器(qi)(qi)可能(neng)在一次電(dian)(dian)(dian)(dian)(dian)流(liu)遠低(di)于失常飽(bao)和(he)值即(ji)過(guo)早飽(bao)和(he)。差(cha)動掩護的(de)(de)暫(zan)態(tai)(tai)不(bu)(bu)(bu)平衡(heng)(heng)電(dian)(dian)(dian)(dian)(dian)流(liu)比(bi)穩態(tai)(tai)時大(da)得多，僅(jin)在整定盤算時將穩態(tai)(tai)不(bu)(bu)(bu)平衡(heng)(heng)電(dian)(dian)(dian)(dian)(dian)流(liu)增大(da)二(er)倍是不(bu)(bu)(bu)敷平安(an)的(de)(de)。采(cai)用(yong)抗飽(bao)和(he)的(de)(de)方法(fa)是使用(yong)帶(dai)有氣(qi)隙的(de)(de)TPY級電(dian)(dian)(dian)(dian)(dian)流(liu)互(hu)(hu)(hu)感(gan)器(qi)(qi)。然則差(cha)動掩護普遍使用(yong)的(de)(de)是P級電(dian)(dian)(dian)(dian)(dian)流(liu)互(hu)(hu)(hu)感(gan)器(qi)(qi)，對(dui)P級電(dian)(dian)(dian)(dian)(dian)流(liu)互(hu)(hu)(hu)感(gan)器(qi)(qi)劃定容許穩態(tai)(tai)偏(pian)(pian)(pian)差(cha)不(bu)(bu)(bu)跨越10%，暫(zan)態(tai)(tai)偏(pian)(pian)(pian)差(cha)必(bi)定要(yao)跨越穩態(tai)(tai)偏(pian)(pian)(pian)差(cha)，在實(shi)用(yong)上可在按穩態(tai)(tai)偏(pian)(pian)(pian)差(cha)選出(chu)的(de)(de)技術(shu)規范(fan)基(ji)礎(chu)上通過(guo)“增密”以(yi)限定暫(zan)態(tai)(tai)偏(pian)(pian)(pian)差(cha)。

采納(na)增密的方法有如下幾種[2]：(1)將精確限值系數增大二(er)倍(容(rong)許短(duan)路電流為額外電流的倍數);(2)將二(er)次額外累贅增大一倍;(3)增大二(er)次電纜(lan)截(jie)面使二(er)次回路的總電阻減(jian)半;(4)改用5P級電流互感器(復(fu)合偏差由(you)10%降為5%)。

今朝110kV及如下電(dian)(dian)(dian)(dian)壓(ya)(ya)品級(ji)均采納(na)P級(ji)電(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)(hu)感(gan)器(qi)(qi)(qi)，220kV變壓(ya)(ya)器(qi)(qi)(qi)亦采納(na)P級(ji)電(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)(hu)感(gan)器(qi)(qi)(qi)或5P級(ji)、PR級(ji)(剩磁系(xi)數小于10%)電(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)(hu)感(gan)器(qi)(qi)(qi)，是以差動掩(yan)護必(bi)要采用抗電(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)(hu)感(gan)器(qi)(qi)(qi)飽和的步伐(fa)。500kV變壓(ya)(ya)器(qi)(qi)(qi)在(zai)500kV側(ce)、220kV側(ce)均用TPY級(ji)電(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)(hu)感(gan)器(qi)(qi)(qi)，對付600MW大型發(fa)電(dian)(dian)(dian)(dian)機變壓(ya)(ya)器(qi)(qi)(qi)組掩(yan)護，500kV側(ce)均采納(na)TPY級(ji)電(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)(hu)感(gan)器(qi)(qi)(qi)，在(zai)發(fa)電(dian)(dian)(dian)(dian)機側(ce)已有TPY級(ji)電(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)(hu)感(gan)器(qi)(qi)(qi)可(ke)選用。