雷擊對電力設備中的架空輸電、配(pei)電線(xian)路有非常(chang)大的危害(hai)。【鈞(jun)和電子?浪涌保護器】今(jin)天(tian)為(wei)您詳細分享這些危害(hai)的具體(ti)表現形(xing)式：

一(yi)是，繞擊形式(shi)

雷(lei)(lei)電(dian)(dian)直接擊在(zai)相導線(xian)(xian)(xian)，對(dui)金屬桿(gan)塔、地(di)(di)面或(huo)屏(ping)(ping)蔽電(dian)(dian)線(xian)(xian)(xian)、中性線(xian)(xian)(xian)或(huo)其他相導線(xian)(xian)(xian)發生閃絡。對(dui)于架(jia)空配(pei)電(dian)(dian)線(xian)(xian)(xian)，視(shi)阻抗典型值500Ω（每(mei)邊），遭到典型的(de)(de)30kA回擊電(dian)(dian)流(liu)直擊將產生7.5MV的(de)(de)過(guo)電(dian)(dian)壓，而配(pei)電(dian)(dian)線(xian)(xian)(xian)的(de)(de)絕(jue)緣水平通常只有100～500kV，所以這種(zhong)直擊雷(lei)(lei)防護是(shi)困難的(de)(de)。有效的(de)(de)防護方法是(shi)在(zai)其上(shang)方架(jia)設接地(di)(di)良(liang)好(hao)的(de)(de)屏(ping)(ping)蔽線(xian)(xian)(xian)。即(ji)使不完(wan)備的(de)(de)屏(ping)(ping)蔽線(xian)(xian)(xian)也(ye)能夠攔(lan)截(jie)大(da)部(bu)分(fen)直擊雷(lei)(lei)，而設計良(liang)好(hao)的(de)(de)屏(ping)(ping)蔽線(xian)(xian)(xian)也(ye)不可能對(dui)直擊雷(lei)(lei)實現100%的(de)(de)攔(lan)截(jie)。在(zai)這種(zhong)屏(ping)(ping)蔽失敗(bai)的(de)(de)情況下(xia)，發生繞擊的(de)(de)雷(lei)(lei)電(dian)(dian)流(liu)也(ye)比(bi)較弱，只要(yao)采取足夠高的(de)(de)絕(jue)緣防護措施，可以避免或(huo)大(da)大(da)減少閃絡的(de)(de)發生。

二是，反擊(ji)形(xing)式

雷(lei)擊于避雷(lei)線(xian)(xian)及其支架結構，對(dui)相(xiang)導線(xian)(xian)產生閃(shan)絡。設計(ji)良好的屏蔽線(xian)(xian)可以把雷(lei)電(dian)直擊后產生反擊事件數降(jiang)低到很少(shao)(shao)，進(jin)一(yi)步采(cai)取絕(jue)緣防護和其他避雷(lei)措(cuo)施能夠避免(mian)或大大減少(shao)(shao)輸(shu)配(pei)電(dian)線(xian)(xian)路的中斷事故(gu)。

三是，感應形(xing)式

靠(kao)近(jin)線路近(jin)處(chu)，未與(yu)線路有任何接觸的(de)某處(chu)發生(sheng)雷擊產生(sheng)感應過電(dian)(dian)壓，一(yi)邊(bian)小于300kV，對于輸配電(dian)(dian)線而言(yan)，不(bu)是主(zhu)要威脅；但對于安裝了復雜電(dian)(dian)氣和(he)電(dian)(dian)子檢測和(he)控制儀器的(de)輸配電(dian)(dian)控制中心(xin)（室）來說，對雷電(dian)(dian)電(dian)(dian)磁脈沖的(de)防護是不(bu)可(ke)疏忽(hu)的(de)。

四是，地(di)下電纜的雷擊危害形(xing)式

目前很多城市地(di)(di)(di)區(qu)的配電(dian)(dian)(dian)(dian)(dian)(dian)線(xian)路(lu)是(shi)利用(yong)埋(mai)設地(di)(di)(di)下(xia)(xia)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)進行輸(shu)配電(dian)(dian)(dian)(dian)(dian)(dian)的。地(di)(di)(di)面(mian)雷擊(ji)電(dian)(dian)(dian)(dian)(dian)(dian)通常只有(you)10cm或(huo)更(geng)小，但該點附近土地(di)(di)(di)內形成(cheng)擊(ji)穿(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)場，若如(ru)讓導電(dian)(dian)(dian)(dian)(dian)(dian)率為0.001S/m，回擊(ji)峰值電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)30kA，擊(ji)穿(chuan)半徑(jing)大(da)約(yue)4m，產(chan)生(sheng)的非均勻電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)(hu)半徑(jing)還(huan)要大(da)，例如(ru)在(zai)(zai)地(di)(di)(di)面(mian)上留(liu)下(xia)(xia)幾米至幾十米長的非均勻電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)(hu)和燒蝕痕跡。由(you)于雷電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)脈沖能(neng)(neng)量主要分布在(zai)(zai)10kHz以下(xia)(xia)，雷電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)穿(chuan)透深度可(ke)以達到幾十米甚(shen)(shen)至一(yi)百米以上，地(di)(di)(di)下(xia)(xia)閃電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)(hu)能(neng)(neng)夠使(shi)得電(dian)(dian)(dian)(dian)(dian)(dian)導率小的砂質(zhi)土壤變(bian)成(cheng)融巖狀玻璃(li)管就是(shi)雷擊(ji)在(zai)(zai)地(di)(di)(di)面(mian)以下(xia)(xia)威力的表現。埋(mai)設于雷擊(ji)電(dian)(dian)(dian)(dian)(dian)(dian)附近的地(di)(di)(di)下(xia)(xia)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)將吸引電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)(hu)，把雷擊(ji)效應傳播到更(geng)大(da)范(fan)圍。1960年以前西歐一(yi)些(xie)國家在(zai)(zai)山區(qu)開挖隧道時屢(lv)(lv)屢(lv)(lv)發生(sheng)隧道內電(dian)(dian)(dian)(dian)(dian)(dian)雷管爆炸的事故便起因于此(ci)。地(di)(di)(di)下(xia)(xia)閃電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)(hu)可(ke)能(neng)(neng)造成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)絕緣層局部(bu)或(huo)大(da)面(mian)積穿(chuan)孔(kong)，甚(shen)(shen)至導致(zhi)中性(xing)線(xian)的熔化(hua)，立即導致(zhi)供電(dian)(dian)(dian)(dian)(dian)(dian)終端或(huo)留(liu)下(xia)(xia)隱患；由(you)此(ci)產(chan)生(sheng)的浪涌電(dian)(dian)(dian)(dian)(dian)(dian)壓可(ke)能(neng)(neng)損壞變(bian)電(dian)(dian)(dian)(dian)(dian)(dian)設備或(huo)危害居民(min)用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)安(an)全，所(suo)以處(chu)在(zai)(zai)雷擊(ji)點下(xia)(xia)方(fang)的地(di)(di)(di)下(xia)(xia)作業(ye)，不(bu)能(neng)(neng)不(bu)考慮潛在(zai)(zai)的雷擊(ji)的危害。

配電室(shi)和(he)輸(shu)變電中心要重(zhong)視直擊雷(lei)危害，更好重(zhong)視起內部的(de)電子(zi)(zi)和(he)電氣設備的(de)雷(lei)擊電磁感(gan)應危害，應該(gai)選用(yong)適配的(de)浪涌保護(hu)器進行電氣和(he)電子(zi)(zi)設備的(de)精細化全面防(fang)護(hu)。