電(dian)(dian)力(li)電(dian)(dian)纜(lan)(lan)是(shi)在電(dian)(dian)力(li)系統的(de)(de)(de)主干線(xian)路中傳輸(shu)和(he)分(fen)配(pei)大功率電(dian)(dian)能的(de)(de)(de)重要工(gong)具(ju)，被制成不同(tong)的(de)(de)(de)電(dian)(dian)壓(ya)等級以(yi)適應(ying)各種應(ying)用場景(jing)，這包括1-500KV及以(yi)上的(de)(de)(de)各種電(dian)(dian)壓(ya)等級。更(geng)具(ju)體地說，電(dian)(dian)力(li)電(dian)(dian)纜(lan)(lan)通常是(shi)按照一定的(de)(de)(de)電(dian)(dian)壓(ya)等級來制造的(de)(de)(de)，這些電(dian)(dian)壓(ya)等級依次為0.5kV、1kV、3kV、6kV、10kV、20kV、35kV、60kV、110kV、220kV、330kV等，其中1kV電(dian)(dian)壓(ya)等級的(de)(de)(de)電(dian)(dian)力(li)電(dian)(dian)纜(lan)(lan)是(shi)使用最多的(de)(de)(de)。

另外，電(dian)壓(ya)也是電(dian)力(li)電(dian)纜的(de)一個(ge)重要(yao)參(can)數(shu)，通常(chang)有兩種(zhong)表示(shi)方(fang)法：一種(zhong)是不太準確地(di)劃分為(wei)低(di)、中、高、超高和特(te)高五個(ge)等級(ji)；另一種(zhong)表示(shi)方(fang)法則是在(zai)相應的(de)電(dian)纜標準里(li)明(ming)確規定，通過給出電(dian)纜所適用的(de)電(dian)網電(dian)壓(ya)，包括3個(ge)電(dian)壓(ya)參(can)數(shu)Uo、U、Um，表示(shi)方(fang)法為(wei)Uo／U（Um）。

電(dian)(dian)(dian)(dian)(dian)(dian)力(li)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)等(deng)級的(de)(de)(de)(de)劃(hua)分以額定電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)U0/U(Um)表(biao)(biao)示，此值(zhi)(zhi)(zhi)表(biao)(biao)示電(dian)(dian)(dian)(dian)(dian)(dian)力(li)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)的(de)(de)(de)(de)絕緣(yuan)水平、使用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)系(xi)(xi)統(tong)(tong)標稱電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)以及(ji)系(xi)(xi)統(tong)(tong)最(zui)高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。其中；UO為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)設計(ji)用(yong)的(de)(de)(de)(de)每(mei)個(ge)導體與接地(di)屏蔽或(huo)護(hu)套(tao)之(zhi)間(jian)(jian)的(de)(de)(de)(de)工(gong)(gong)(gong)頻電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，其值(zhi)(zhi)(zhi)與系(xi)(xi)統(tong)(tong)對電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)有(you)關(guan)(guan)，但(dan)并(bing)非相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。因電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)標準規定所(suo)有(you)與工(gong)(gong)(gong)頻電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)有(you)關(guan)(guan)的(de)(de)(de)(de)試驗項(xiang)目(mu)對電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)絕緣(yuan)施加的(de)(de)(de)(de)工(gong)(gong)(gong)頻電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)均為(wei)U0的(de)(de)(de)(de)倍數表(biao)(biao)示，UO實際上(shang)表(biao)(biao)示電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)絕緣(yuan)水平。即電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)絕緣(yuan)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)和電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)持續時間(jian)(jian)的(de)(de)(de)(de)能力(li)。應按(an)電(dian)(dian)(dian)(dian)(dian)(dian)力(li)系(xi)(xi)統(tong)(tong)中性(xing)點接地(di)方式(shi)單(dan)相(xiang)接地(di)故(gu)障時非故(gu)障相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)升高(gao)，和系(xi)(xi)統(tong)(tong)接地(di)故(gu)障排除(chu)時間(jian)(jian)合理地(di)選擇(ze)電(dian)(dian)(dian)(dian)(dian)(dian)力(li)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)的(de)(de)(de)(de)額定電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)U0值(zhi)(zhi)(zhi)，以便于保證電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)可靠運行。U為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)設計(ji)采(cai)用(yong)的(de)(de)(de)(de)任何兩個(ge)導體之(zhi)間(jian)(jian)最(zui)大工(gong)(gong)(gong)頻電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，即三相(xiang)系(xi)(xi)統(tong)(tong)最(zui)高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)或(huo)設備最(zui)高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)或(huo)者說每(mei)一個(ge)導體與屏蔽或(huo)護(hu)套(tao)之(zhi)間(jian)(jian)的(de)(de)(de)(de)最(zui)大工(gong)(gong)(gong)頻電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。以上(shang)三個(ge)值(zhi)(zhi)(zhi)的(de)(de)(de)(de)單(dan)位均為(wei)KV。

由于電(dian)(dian)(dian)(dian)(dian)力(li)(li)系(xi)(xi)統(tong)(tong)中性點(dian)接地方(fang)(fang)式，運行情況對系(xi)(xi)統(tong)(tong)設備的(de)絕緣水平要(yao)求不同，因而了解(jie)電(dian)(dian)(dian)(dian)(dian)力(li)(li)電(dian)(dian)(dian)(dian)(dian)纜額(e)定電(dian)(dian)(dian)(dian)(dian)壓含義，合理(li)地確定電(dian)(dian)(dian)(dian)(dian)力(li)(li)電(dian)(dian)(dian)(dian)(dian)纜額(e)定電(dian)(dian)(dian)(dian)(dian)壓時(shi)正確選用(yong)電(dian)(dian)(dian)(dian)(dian)力(li)(li)電(dian)(dian)(dian)(dian)(dian)纜，保證其可靠(kao)運行的(de)重要(yao)前提。系(xi)(xi)統(tong)(tong)電(dian)(dian)(dian)(dian)(dian)壓等級使用(yong)電(dian)(dian)(dian)(dian)(dian)纜系(xi)(xi)統(tong)(tong)的(de)標稱電(dian)(dian)(dian)(dian)(dian)壓U（標識(shi)系(xi)(xi)統(tong)(tong)的(de)相與(yu)相之間(jian)的(de)電(dian)(dian)(dian)(dian)(dian)壓有效值與(yu)電(dian)(dian)(dian)(dian)(dian)纜額(e)定電(dian)(dian)(dian)(dian)(dian)壓U一致(zhi)）。結合電(dian)(dian)(dian)(dian)(dian)力(li)(li)系(xi)(xi)統(tong)(tong)中性點(dian)接地方(fang)(fang)式以(yi)及我國電(dian)(dian)(dian)(dian)(dian)力(li)(li)電(dian)(dian)(dian)(dian)(dian)纜標準(zhun)和相應IEC標準(zhun)對系(xi)(xi)統(tong)(tong)的(de)分類原(yuan)則(ze)，可以(yi)認為：

電(dian)纜的(de)額定電(dian)壓取(qu)決于(yu)電(dian)纜使用系(xi)統的(de)運行條件，分為三類；

1） A類；接地故障(zhang)在(zai)任何情(qing)況下在(zai)1min內(nei)切除(chu)。

2） B類；單相(xiang)接地故(gu)障一般不(bu)(bu)超過(guo)1h。滿(man)足GB/T12706標準的電纜(lan)允許更(geng)長(chang)帶(dai)故(gu)障運行時間，但任何情(qing)況下不(bu)(bu)宜(yi)超過(guo)8h,年接地故(gu)障總持(chi)續時間不(bu)(bu)宜(yi)超過(guo)125h.

3） C類；對接地故障(zhang)持續時間不作任何限制。