為什么(me)在使用電纜(lan)故障(zhang)測(ce)試(shi)儀時(shi)找(zhao)不(bu)出故障(zhang)點(dian)？電纜(lan)故障(zhang)測(ce)試(shi)儀正確的打開方(fang)法是什么(me)，那(nei)我們需要先了解(jie)(jie)一些電纜(lan)故障(zhang)的常用問題，然后根據(ju)不(bu)同(tong)的問題來有效的解(jie)(jie)決故障(zhang)問題。

        隨著(zhu)我(wo)國(guo)電力系統的(de)發展，高壓電纜(lan)(lan)(lan)的(de)鋪設(she)也越來(lai)越普遍，基本(ben)上配電站(zhan)與站(zhan)之(zhi)間連接(jie)的(de)電纜(lan)(lan)(lan)都很(hen)長，只要(yao)電纜(lan)(lan)(lan)出現(xian)故(gu)障(zhang)(zhang)(zhang)(zhang)，排(pai)查起來(lai)就很(hen)困難，而且大都是地埋電纜(lan)(lan)(lan)，很(hen)難人為是判斷(duan)，這(zhe)時就需(xu)要(yao)電纜(lan)(lan)(lan)故(gu)障(zhang)(zhang)(zhang)(zhang)測試儀來(lai)替我(wo)們(men)(men)去判斷(duan)正確的(de)故(gu)障(zhang)(zhang)(zhang)(zhang)點(dian)，以便我(wo)們(men)(men)快速恢復供電，那么我(wo)們(men)(men)根據現(xian)在比較(jiao)常見的(de)幾個電纜(lan)(lan)(lan)故(gu)障(zhang)(zhang)(zhang)(zhang)來(lai)分析問題。

        電纜故(gu)障(zhang)常用分為高(gao)阻(zu)性(xing)短路故(gu)障(zhang)、相間短路、低阻(zu)故(gu)障(zhang)、閃絡性(xing)故(gu)障(zhang)等現場常見的幾(ji)種故(gu)障(zhang)。

 1、低壓脈(mo)(mo)沖(chong)反(fan)(fan)(fan)射(she)(she)(she)(she)法適用于低阻(zu)( 低于10倍波(bo)(bo)阻(zu)抗(kang)(kang)(kang)) 、接(jie)地(di)(di)及(ji)開(kai)路故(gu)(gu)(gu)障，并可以(yi)測(ce)試(shi)電(dian)(dian)(dian)纜的(de)(de)(de)(de)(de)(de)全長和電(dian)(dian)(dian)波(bo)(bo)在(zai)(zai)電(dian)(dian)(dian)纜中的(de)(de)(de)(de)(de)(de)傳播速度，當(dang)電(dian)(dian)(dian)纜發生(sheng)低阻(zu)或接(jie)地(di)(di)故(gu)(gu)(gu)障時(shi)(shi)，電(dian)(dian)(dian)纜故(gu)(gu)(gu)障點處的(de)(de)(de)(de)(de)(de)等效(xiao)阻(zu)抗(kang)(kang)(kang)應(ying)為(wei)(wei)故(gu)(gu)(gu)障電(dian)(dian)(dian)阻(zu)與電(dian)(dian)(dian)纜特(te)(te)性(xing)阻(zu)抗(kang)(kang)(kang)的(de)(de)(de)(de)(de)(de)并聯。電(dian)(dian)(dian)纜故(gu)(gu)(gu)障電(dian)(dian)(dian)阻(zu)越(yue)(yue)小(xiao)，反(fan)(fan)(fan)射(she)(she)(she)(she)波(bo)(bo)形(xing)越(yue)(yue)明顯。當(dang)電(dian)(dian)(dian)纜故(gu)(gu)(gu)障電(dian)(dian)(dian)阻(zu)為(wei)(wei)零時(shi)(shi)為(wei)(wei)全反(fan)(fan)(fan)射(she)(she)(she)(she)，由(you)于測(ce)試(shi)端等效(xiao)阻(zu)抗(kang)(kang)(kang)( 測(ce)試(shi)儀器(qi)的(de)(de)(de)(de)(de)(de)輸入阻(zu)抗(kang)(kang)(kang)) 大于電(dian)(dian)(dian)纜特(te)(te)性(xing)阻(zu)抗(kang)(kang)(kang)，所(suo)以(yi)在(zai)(zai)測(ce)試(shi)端產(chan)生(sheng)同極性(xing)反(fan)(fan)(fan)射(she)(she)(she)(she)脈(mo)(mo)沖(chong)。而在(zai)(zai)低阻(zu)或接(jie)地(di)(di)故(gu)(gu)(gu)障處，由(you)于故(gu)(gu)(gu)障電(dian)(dian)(dian)阻(zu)小(xiao)于電(dian)(dian)(dian)纜特(te)(te)性(xing)阻(zu)抗(kang)(kang)(kang)，所(suo)以(yi)入射(she)(she)(she)(she)脈(mo)(mo)沖(chong)進(jin)行故(gu)(gu)(gu)障點后產(chan)生(sheng)反(fan)(fan)(fan)極性(xing)脈(mo)(mo)沖(chong)，并傳輸到(dao)測(ce)試(shi)端，接(jie)收到(dao)的(de)(de)(de)(de)(de)(de)反(fan)(fan)(fan)極性(xing)脈(mo)(mo)沖(chong)的(de)(de)(de)(de)(de)(de)下降(jiang)沿(yan)就對應(ying)電(dian)(dian)(dian)纜故(gu)(gu)(gu)障點的(de)(de)(de)(de)(de)(de)反(fan)(fan)(fan)射(she)(she)(she)(she)波(bo)(bo)形(xing)。當(dang)電(dian)(dian)(dian)纜發生(sheng)開(kai)路故(gu)(gu)(gu)障時(shi)(shi)，電(dian)(dian)(dian)纜故(gu)(gu)(gu)障等效(xiao)阻(zu)抗(kang)(kang)(kang)為(wei)(wei)故(gu)(gu)(gu)障電(dian)(dian)(dian)阻(zu)與電(dian)(dian)(dian)纜特(te)(te)性(xing)阻(zu)抗(kang)(kang)(kang)的(de)(de)(de)(de)(de)(de)串聯，開(kai)路即相當(dang)于故(gu)(gu)(gu)障電(dian)(dian)(dian)阻(zu)為(wei)(wei)無窮大，這種(zhong)情況入射(she)(she)(she)(she)脈(mo)(mo)沖(chong)將形(xing)成全反(fan)(fan)(fan)射(she)(she)(she)(she)，在(zai)(zai)測(ce)試(shi)端產(chan)生(sheng)同極性(xing)反(fan)(fan)(fan)射(she)(she)(she)(she)脈(mo)(mo)沖(chong)，接(jie)收到(dao)同極性(xing)的(de)(de)(de)(de)(de)(de)脈(mo)(mo)沖(chong)的(de)(de)(de)(de)(de)(de)上升沿(yan)與故(gu)(gu)(gu)障點的(de)(de)(de)(de)(de)(de)反(fan)(fan)(fan)射(she)(she)(she)(she)波(bo)(bo)形(xing)對應(ying)

        2、首(shou)先(xian)使(shi)(shi)用一(yi)定電(dian)(dian)(dian)(dian)壓(ya)(ya)等級、一(yi)定能(neng)量(liang)的(de)(de)(de)(de)(de)高(gao)壓(ya)(ya)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)在(zai)電(dian)(dian)(dian)(dian)纜(lan)的(de)(de)(de)(de)(de)測(ce)試(shi)(shi)(shi)端施加(jia)(jia)給故(gu)(gu)(gu)障(zhang)(zhang)(zhang)電(dian)(dian)(dian)(dian)纜(lan)，讓電(dian)(dian)(dian)(dian)纜(lan)的(de)(de)(de)(de)(de)高(gao)阻(zu)故(gu)(gu)(gu)障(zhang)(zhang)(zhang)點(dian)(dian)發(fa)生擊穿(chuan)燃(ran)弧。同(tong)時(shi)(shi)，在(zai)測(ce)試(shi)(shi)(shi)端加(jia)(jia)入測(ce)量(liang)用的(de)(de)(de)(de)(de)低(di)壓(ya)(ya)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)，測(ce)量(liang)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)到達電(dian)(dian)(dian)(dian)纜(lan)的(de)(de)(de)(de)(de)高(gao)阻(zu)故(gu)(gu)(gu)障(zhang)(zhang)(zhang)點(dian)(dian)時(shi)(shi)，遇(yu)到電(dian)(dian)(dian)(dian)弧，在(zai)電(dian)(dian)(dian)(dian)弧的(de)(de)(de)(de)(de)表面發(fa)生反射(she)。由于(yu)燃(ran)弧時(shi)(shi)，高(gao)阻(zu)故(gu)(gu)(gu)障(zhang)(zhang)(zhang)變(bian)成了(le)瞬(shun)間的(de)(de)(de)(de)(de)短(duan)(duan)路故(gu)(gu)(gu)障(zhang)(zhang)(zhang)，低(di)壓(ya)(ya)測(ce)量(liang)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)將(jiang)(jiang)發(fa)生明顯的(de)(de)(de)(de)(de)阻(zu)抗特(te)征(zheng)變(bian)化，使(shi)(shi)得(de)閃絡測(ce)量(liang)的(de)(de)(de)(de)(de)波(bo)(bo)形(xing)變(bian)為低(di)壓(ya)(ya)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)短(duan)(duan)路波(bo)(bo)形(xing)，使(shi)(shi)得(de)波(bo)(bo)形(xing)判(pan)別特(te)別簡單(dan)(dan)清晰。這就(jiu)是我們稱(cheng)之(zhi)為的(de)(de)(de)(de)(de)“二(er)次脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)法"。接收到的(de)(de)(de)(de)(de)低(di)壓(ya)(ya)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)反射(she)波(bo)(bo)形(xing)相(xiang)(xiang)當于(yu)一(yi)個線芯對(dui)地(di)*短(duan)(duan)路的(de)(de)(de)(de)(de)波(bo)(bo)形(xing)。將(jiang)(jiang)釋放高(gao)壓(ya)(ya)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)時(shi)(shi)與(yu)未釋放高(gao)壓(ya)(ya)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)時(shi)(shi)所得(de)到的(de)(de)(de)(de)(de)低(di)壓(ya)(ya)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)波(bo)(bo)形(xing)進(jin)行(xing)疊加(jia)(jia)，2個波(bo)(bo)形(xing)會(hui)有一(yi)個發(fa)散點(dian)(dian)，這發(fa)散點(dian)(dian)就(jiu)是電(dian)(dian)(dian)(dian)纜(lan)故(gu)(gu)(gu)障(zhang)(zhang)(zhang)點(dian)(dian)的(de)(de)(de)(de)(de)反射(she)波(bo)(bo)形(xing)點(dian)(dian)。這種(zhong)方法把低(di)壓(ya)(ya)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)法和高(gao)壓(ya)(ya)閃絡技術結合(he)在(zai)一(yi)起，使(shi)(shi)測(ce)試(shi)(shi)(shi)人員更(geng)容易判(pan)斷(duan)出電(dian)(dian)(dian)(dian)纜(lan)故(gu)(gu)(gu)障(zhang)(zhang)(zhang)點(dian)(dian)的(de)(de)(de)(de)(de)位置。與(yu)傳統的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)纜(lan)故(gu)(gu)(gu)障(zhang)(zhang)(zhang)測(ce)試(shi)(shi)(shi)方法相(xiang)(xiang)比,二(er)次脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)法的(de)(de)(de)(de)(de)先(xian)進(jin)之(zhi)處，是將(jiang)(jiang)沖(chong)(chong)擊高(gao)壓(ya)(ya)閃絡法中的(de)(de)(de)(de)(de)復(fu)雜波(bo)(bo)形(xing)簡化為低(di)壓(ya)(ya)脈(mo)(mo)(mo)(mo)(mo)(mo)沖(chong)(chong)短(duan)(duan)路故(gu)(gu)(gu)障(zhang)(zhang)(zhang)波(bo)(bo)形(xing)，所以判(pan)讀極(ji)為簡單(dan)(dan)，可(ke)準確標定故(gu)(gu)(gu)障(zhang)(zhang)(zhang)距(ju)離。

       3、三(san)次(ci)(ci)脈沖(chong)法(fa)采用雙沖(chong)擊方法(fa)延長(chang)燃弧時間(jian)(jian)并穩(wen)弧,能夠輕(qing)易(yi)地定(ding)(ding)(ding)位高阻故(gu)障(zhang)(zhang)和閃(shan)絡性(xing)故(gu)障(zhang)(zhang)。三(san)次(ci)(ci)脈沖(chong)法(fa)技術先進(jin),操作簡單,波(bo)(bo)(bo)形(xing)(xing)清(qing)晰,定(ding)(ding)(ding)位快速(su)準(zhun)確(que),目前已經成(cheng)為高阻故(gu)障(zhang)(zhang)和閃(shan)絡性(xing)故(gu)障(zhang)(zhang)的(de)(de)主流定(ding)(ding)(ding)位方法(fa)。三(san)次(ci)(ci)脈沖(chong)法(fa)是(shi)二(er)次(ci)(ci)脈沖(chong)法(fa)的(de)(de)升級，其方法(fa)是(shi)首(shou)先在不(bu)擊穿被(bei)測(ce)電(dian)纜(lan)故(gu)障(zhang)(zhang)點的(de)(de)情(qing)況下，測(ce)得(de)低壓脈沖(chong)的(de)(de)反射波(bo)(bo)(bo)形(xing)(xing)，緊(jin)接著用高壓脈沖(chong)擊穿電(dian)纜(lan)的(de)(de)故(gu)障(zhang)(zhang)點產生(sheng)電(dian)弧，在電(dian)弧電(dian)壓降到一定(ding)(ding)(ding)值時觸(chu)發中壓脈沖(chong)來(lai)(lai)穩(wen)定(ding)(ding)(ding)和延長(chang)電(dian)弧時間(jian)(jian)，之后再發出(chu)低壓脈沖(chong)，從(cong)而得(de)到故(gu)障(zhang)(zhang)點的(de)(de)反射波(bo)(bo)(bo)形(xing)(xing)，兩(liang)條波(bo)(bo)(bo)形(xing)(xing)疊加后同樣可以(yi)發現發散(san)點就(jiu)是(shi)故(gu)障(zhang)(zhang)點對應的(de)(de)位置。由于采用了中壓脈沖(chong)來(lai)(lai)穩(wen)定(ding)(ding)(ding)和延長(chang)電(dian)弧時間(jian)(jian)，它比二(er)次(ci)(ci)脈沖(chong)法(fa)更(geng)容易(yi)找到故(gu)障(zhang)(zhang)點波(bo)(bo)(bo)形(xing)(xing)。

       電纜(lan)故障(zhang)測試儀常要解(jie)決的問(wen)題：

       1、電(dian)纜故障的多(duo)樣性及復(fu)雜性決(jue)定了電(dian)纜故障測試(shi)儀器需要功能齊全(quan)，測試(shi)方法多(duo)樣。

      2、解(jie)決故障是要通過許多儀器配合使用，才能(neng)達到解(jie)決故障的結果。

      3、電纜(lan)的(de)絕緣、故障發(fa)生的(de)部(bu)位、不(bu)同(tong)性質的(de)故障，都需(xu)要不(bu)同(tong)的(de)測試方法。

      4、有的(de)時(shi)候電(dian)纜故障測(ce)(ce)試(shi)的(de)難點在(zai)于(yu)厚達一米多的(de)積雪以及惡劣的(de)天氣（氣溫(wen)低達零下20多度），這對于(yu)地下電(dian)纜探測(ce)(ce)儀及測(ce)(ce)試(shi)人員(yuan)來(lai)(lai)來(lai)(lai)說也是一種考驗