電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)(gu)(gu)(gu)障測(ce)(ce)(ce)試(shi)(shi)儀(yi)之(zhi)高(gao)壓沖(chong)(chong)擊閃絡法可(ke)以測(ce)(ce)(ce)試(shi)(shi)電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)的高(gao)阻(zu)(zu)泄漏故(gu)(gu)(gu)(gu)障、高(gao)阻(zu)(zu)閃絡性故(gu)(gu)(gu)(gu)障、低阻(zu)(zu)短(duan)路故(gu)(gu)(gu)(gu)障和(he)斷線(xian)故(gu)(gu)(gu)(gu)障是(shi)一(yi)(yi)種可(ke)靠、適應性較廣的電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)故(gu)(gu)(gu)(gu)障測(ce)(ce)(ce)尋手段。高(gao)壓沖(chong)(chong)擊閃絡法是(shi)在故(gu)(gu)(gu)(gu)障電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)的始端(duan)施加一(yi)(yi)個沖(chong)(chong)擊高(gao)壓，將故(gu)(gu)(gu)(gu)障點(dian)用電(dian)(dian)(dian)(dian)弧(hu)擊穿(chuan)(chuan)。利用故(gu)(gu)(gu)(gu)障點(dian)擊穿(chuan)(chuan)瞬間的電(dian)(dian)(dian)(dian)壓突跳作(zuo)為測(ce)(ce)(ce)試(shi)(shi)信(xin)號(hao)。觀察此信(xin)號(hao)在故(gu)(gu)(gu)(gu)障點(dian)和(he)電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)始端(duan)之(zhi)間往返一(yi)(yi)次的時間進(jin)行測(ce)(ce)(ce)距。多使用電(dian)(dian)(dian)(dian)流(liu)(liu)取(qu)(qu)樣法采取(qu)(qu)測(ce)(ce)(ce)試(shi)(shi)信(xin)號(hao)。電(dian)(dian)(dian)(dian)流(liu)(liu)取(qu)(qu)樣法利用電(dian)(dian)(dian)(dian)磁感應原理，用電(dian)(dian)(dian)(dian)流(liu)(liu)互感器拾取(qu)(qu)接地線(xian)上的電(dian)(dian)(dian)(dian)流(liu)(liu)信(xin)號(hao)來獲得電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)中的電(dian)(dian)(dian)(dian)波電(dian)(dian)(dian)(dian)流(liu)(liu)反射信(xin)號(hao)。
與高壓發生器、市電沒有(you)電氣(qi)上的(de)(de)關系(xi)，所以特(te)別安全。電流取樣法所得(de)波(bo)形(xing)(xing)，反射(she)波(bo)形(xing)(xing)特(te)征(zheng)拐點清晰，特(te)別有(you)利于故障距(ju)離分析和定(ding)位。但是電流取樣法的(de)(de)測試(shi)波(bo)形(xing)(xing)較為復(fu)雜(za);不同類(lei)型、不同長度(du)、不同故障距(ju)離、不同的(de)(de)沖(chong)擊高(gao)壓所得(de)的(de)(de)波(bo)形(xing)(xing)千變萬(wan)化(hua)，往往與(yu)標準波(bo)形(xing)(xing)相差甚遠。由(you)于掌握(wo)不了波(bo)形(xing)(xing)規律，常常發生(sheng)誤(wu)判(pan)錯判(pan)。
