電纜故障定位方法[實用]
標簽: 電纜故障測試儀
目前準確定位電纜故障點常用方法有電橋法,沖閃法,跨步電壓法等,但是現場情況比較復雜,不同的測法有不同的優越性也有局限性。比較傳統的電纜故障定位方法是(shi)聽聲法(fa)。這種電(dian)纜故(gu)障定(ding)位(wei)方法(fa)的特(te)點(dian)是(shi)簡單(dan)易行,尤其是(shi)放電(dian)聲較(jiao)大的時候(hou),效果還是(shi)比較(jiao)好的。然而(er),當故(gu)障點(dian)的直流電(dian)阻較(jiao)小時,放電(dian)聲不太大,這個(ge)時候(hou)難以奏效。現(xian)在比較(jiao)普(pu)遍使(shi)用的定(ding)位(wei)儀(yi)是(shi)將微弱的機(ji)(ji)械振動波首先轉換成電(dian)信(xin)號,由放大電(dian)路將這一電(dian)信(xin)號進行足夠的放大后(hou),再(zai)通過耳機(ji)(ji)還原成聲音,然后(hou)通過人機(ji)(ji)的有機(ji)(ji)配(pei)合,準(zhun)確地確定(ding)故(gu)障點(dian)的位(wei)置。
由于電(dian)纜(lan)(lan)線路不(bu)可能完(wan)全直線敷(fu)設(she),用電(dian)纜(lan)(lan)故(gu)障探測儀(yi)僅能對電(dian)纜(lan)(lan)故(gu)障的大致(zhi)位(wei)置(zhi)進行判斷(duan),而不(bu)能確切給出電(dian)纜(lan)(lan)敷(fu)設(she)后的準確故(gu)障點,所(suo)以(yi)電(dian)纜(lan)(lan)故(gu)障定(ding)位(wei)非常的重要。
不(bu)同性(xing)質的(de)電(dian)纜故(gu)障,在定點技術上略有差(cha)異:
(a)對于低阻故障的定點,由(you)于這(zhe)類故(gu)障電(dian)(dian)(dian)阻小,因此故(gu)障點(dian)的(de)(de)放電(dian)(dian)(dian)間隙也(ye)小,致使施加的(de)(de)沖(chong)擊高(gao)壓在(zai)不很高(gao)的(de)(de)情(qing)況下(xia),故(gu)障點(dian)便(bian)發生閃絡(luo)放電(dian)(dian)(dian)。這(zhe)時(shi)因閃絡(luo)放電(dian)(dian)(dian)而產生的(de)(de)沖(chong)擊振動波(bo)也(ye)小,再加上現場其(qi)他因素(su)的(de)(de)干擾,放電(dian)(dian)(dian)聲往往不易分(fen)辨(bian)甚(shen)至聽不到放電(dian)(dian)(dian)聲。這(zhe)時(shi)可控制沖(chong)擊電(dian)(dian)(dian)壓的(de)(de)高(gao)低,并通過(guo)加大(da)貯能電(dian)(dian)(dian)容器的(de)(de)電(dian)(dian)(dian)容量,增強放電(dian)(dian)(dian)強度,從而獲得較(jiao)強、較(jiao)大(da)的(de)(de)放電(dian)(dian)(dian)聲,便(bian)于收聽、分(fen)析和判斷(duan)故(gu)障點(dian)的(de)(de)位置。
(b)對于開路故障的定點,是在(zai)(zai)故障相(xiang)的(de)一端(duan)加沖擊高(gao)壓,而(er)故障相(xiang)的(de)另一端(duan)用(yong)另外兩相(xiang)和電(dian)纜鉛(qian)包(bao)連(lian)接后充分接地,然后利用(yong)定(ding)點儀在(zai)(zai)粗測范圍內進行(xing)定(ding)點。因開(kai)路故障類似于(yu)高(gao)阻故障,其定(ding)點方(fang)法(fa)與(yu)高(gao)阻故障的(de)定(ding)點方(fang)法(fa)相(xiang)同。
(c)對于高阻故障的定點,由(you)于故障(zhang)的(de)(de)阻抗較高,探測時施(shi)加的(de)(de)沖擊電壓較高,故障(zhang)點才(cai)會(hui)發生閃(shan)絡放電,故放電聲和由(you)此而產生的(de)(de)沖擊振動波一般說來都比(bi)較大(da),較便于收(shou)聽(ting)、分析和辨別。
電纜故障定位儀采用(yong)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)障(zhang)定(ding)(ding)點新(xin)(xin)理論。是根據 新(xin)(xin)研究成果(guo)而開發的(de)(de)(de)具(ju)有高(gao)抗干擾性(xing)(xing)(xing),高(gao)靈敏度,新(xin)(xin)型(xing)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)障(zhang)定(ding)(ding)點測試(shi)(shi)儀器。電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)障(zhang)定(ding)(ding)點儀器采用(yong)先進的(de)(de)(de)模(mo)擬低噪聲設計和(he)高(gao)性(xing)(xing)(xing)能(neng)濾波電(dian)(dian)(dian)(dian)(dian)路相結合,使(shi)電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)障(zhang)定(ding)(ding)點儀抗干擾性(xing)(xing)(xing)能(neng)有了極(ji)大的(de)(de)(de)提高(gao),采用(yong)設計和(he)地裝(zhuang)配工藝使(shi)電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)障(zhang)定(ding)(ding)點儀具(ju)有目前國(guo)內 高(gao)水準。對各類電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)障(zhang)可地進行定(ding)(ding)點,特別(bie)是對交聯電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)和(he)電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)封閉性(xing)(xing)(xing)電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)障(zhang)具(ju)有獨(du)到的(de)(de)(de)測試(shi)(shi)效果(guo)。是電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)障(zhang)測試(shi)(shi)儀器中(zhong) 新(xin)(xin)的(de)(de)(de)更新(xin)(xin)換代產(chan)品(pin)。