交流輸電(dian)(dian)線(xian)(xian)(xian)(xian)路(lu)(lu)的(de)電(dian)(dian)暈(yun)(yun)損失(shi)主要與(yu)導(dao)線(xian)(xian)(xian)(xian)表(biao)面(mian)場(chang) 強和天(tian)氣(qi)有關(guan)，根據絕緣水平要求確定了(le)相(xiang)間(jian)(jian)距(ju)離后，導(dao)線(xian)(xian)(xian)(xian)表(biao)面(mian)場(chang)強主要與(yu)導(dao)線(xian)(xian)(xian)(xian)分(fen)(fen)(fen)裂數(shu)、分(fen)(fen)(fen)裂間(jian)(jian)距(ju)和子(zi)導(dao)線(xian)(xian)(xian)(xian)直徑(jing)(jing)有關(guan)，分(fen)(fen)(fen)裂數(shu)越多(duo)，子(zi)導(dao)線(xian)(xian)(xian)(xian)直徑(jing)(jing)越大，表(biao)面(mian)場(chang)強越小。擴(kuo)(kuo)徑(jing)(jing)導(dao)線(xian)(xian)(xian)(xian)通(tong)過(guo)支撐鋁(lv)線(xian)(xian)(xian)(xian)疏繞的(de)方式(shi)擴(kuo)(kuo)大了(le)導(dao)線(xian)(xian)(xian)(xian)外徑(jing)(jing)，這(zhe)樣(yang)可減小導(dao)線(xian)(xian)(xian)(xian)表(biao)面(mian)的(de)電(dian)(dian)場(chang)強度(du)和電(dian)(dian)暈(yun)(yun)放電(dian)(dian)，降低噪聲，減少(shao)對無線(xian)(xian)(xian)(xian)電(dian)(dian)的(de)干擾(rao)。相(xiang)對于常(chang)規導(dao)線(xian)(xian)(xian)(xian)，擴(kuo)(kuo)徑(jing)(jing)導(dao)線(xian)(xian)(xian)(xian)重量較輕，安裝敷設后的(de)塑蠕伸長減小，導(dao)線(xian)(xian)(xian)(xian)永久變形減少(shao)，在滿足(zu)輸送(song)容量要求和環境保護指標的(de)前提下，可大幅(fu)降低線(xian)(xian)(xian)(xian)路(lu)(lu)整體(ti)造價。簡單說來，擴(kuo)(kuo)徑(jing)(jing)導(dao)線(xian)(xian)(xian)(xian)是(shi)從常(chang)規導(dao)線(xian)(xian)(xian)(xian)中抽取數(shu)股鋁(lv)線(xian)(xian)(xian)(xian)后繞制(zhi)而成的(de)。

    分(fen)裂(lie)(lie)導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)是(shi)由三根(gen)或(huo)四根(gen)單芯導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)經(jing)過某種工藝制造在一起(qi)的(de)一種可分(fen)裂(lie)(lie)的(de)導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)，或(huo)者稱導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)束， 這(zhe)種分(fen)裂(lie)(lie)導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)不僅(jin)僅(jin)是(shi)形式上與(yu)常規(gui)導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)不同，由于分(fen)裂(lie)(lie)導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)可使導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)周(zhou)圍磁場分(fen)布(bu)改變，從而等(deng)效地增大(da)了導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)半徑(jing)，減小了導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)電抗；同時(shi)也改變了導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)周(zhou)圍的(de)電場分(fen)布(bu)， 使導(dao)(dao)(dao)(dao)(dao)線(xian)(xian)(xian)的(de)電納(na)也相應增大(da)。