電纜故障指示器原理:電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)故(gu)障(zhang)(zhang)指示器(qi)是一種能(neng)夠根(gen)據電(dian)(dian)(dian)(dian)(dian)(dian)網(wang)線路中(zhong)電(dian)(dian)(dian)(dian)(dian)(dian)流、電(dian)(dian)(dian)(dian)(dian)(dian)壓的(de)變(bian)化(hua)來對電(dian)(dian)(dian)(dian)(dian)(dian)網(wang)運行故(gu)障(zhang)(zhang)進(jin)行智能(neng)判(pan)斷、檢(jian)測以(yi)及定位的(de)重要(yao)設備(bei)儀器(qi)。它通常被安裝在電(dian)(dian)(dian)(dian)(dian)(dian)力輸送網(wang)絡之中(zhong)，主要(yao)用來監視檢(jian)測線路可能(neng)出現的(de)短(duan)路以(yi)及單相接地等故(gu)障(zhang)(zhang)，當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)力網(wang)絡中(zhong)發生短(duan)路現象，則線路中(zhong)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)流值瞬間突(tu)變(bian)，此時的(de)故(gu)障(zhang)(zhang)電(dian)(dian)(dian)(dian)(dian)(dian)流在通過(guo)指示器(qi)時就(jiu)會(hui)觸動指示器(qi)的(de)翻牌(pai)或閃(shan)光動作(zuo)，而非故(gu)障(zhang)(zhang)電(dian)(dian)(dian)(dian)(dian)(dian)流則不會(hui)影響其正(zheng)常顯示。
同時電纜故障指示器大都配備了(le)自(zi)動延時(shi)復位功能，當故障(zhang)排(pai)除(chu)之后，恢(hui)復電力輸(shu)送，故障(zhang)指示器會(hui)自(zi)動復位，為(wei)下(xia)一次的檢測做好準備，這使得電網日常的檢測維護更加方便快捷。
目前電(dian)力網(wang)絡輸送(song)中容易發生的(de)(de)(de)(de)是(shi)相(xiang)(xiang)(xiang)間短路(lu)(lu)(lu)和(he)單(dan)相(xiang)(xiang)(xiang)接(jie)地兩(liang)(liang)類故(gu)(gu)障(zhang)，因此故(gu)(gu)障(zhang)指(zhi)(zhi)(zhi)(zhi)示器的(de)(de)(de)(de)設計也是(shi)按照這兩(liang)(liang)類故(gu)(gu)障(zhang)而(er)設定(ding)的(de)(de)(de)(de)。相(xiang)(xiang)(xiang)間短路(lu)(lu)(lu)指(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)(de)是(shi)輸送(song)線路(lu)(lu)(lu)的(de)(de)(de)(de)兩(liang)(liang)相(xiang)(xiang)(xiang)或(huo)三相(xiang)(xiang)(xiang)之(zhi)間相(xiang)(xiang)(xiang)互(hu)接(jie)觸，從(cong)而(er)造成了(le)線路(lu)(lu)(lu)短路(lu)(lu)(lu)故(gu)(gu)障(zhang)的(de)(de)(de)(de)發生。當相(xiang)(xiang)(xiang)間發生短路(lu)(lu)(lu)時，線路(lu)(lu)(lu)中的(de)(de)(de)(de)瞬間電(dian)流突然增大(da)，并形成電(dian)流突躍(yue)，故(gu)(gu)障(zhang)指(zhi)(zhi)(zhi)(zhi)示器內部對電(dian)流突變值(zhi)進行了(le)設定(ding)，若電(dian)流變化量超過了(le)設定(ding)值(zhi)，那么指(zhi)(zhi)(zhi)(zhi)示器就會顯示與(yu)之(zhi)對應(ying)的(de)(de)(de)(de)故(gu)(gu)障(zhang)信號。
對(dui)于(yu)單相(xiang)接地(di)的(de)(de)判斷(duan)依據和(he)原理目(mu)前使用(yong)多的(de)(de)是零序電(dian)流(liu)幅值(zhi)法，即在中性(xing)點不直接接地(di)的(de)(de)配(pei)電(dian)網絡中采集暫時的(de)(de)電(dian)流(liu)、電(dian)壓等數據值(zhi)，然后采用(yong)穩(wen)態(tai)零序電(dian)流(liu)和(he)電(dian)壓的(de)(de)基波或高次(ci)諧波對(dui)采集的(de)(de)數據進行計算和(he)分析，從而線路中的(de)(de)電(dian)流(liu)電(dian)壓值(zhi)進行判定，若為故障電(dian)流(liu)則顯(xian)示翻牌或者(zhe)亮燈，反(fan)之(zhi)指示器無變化(hua)。
