擴(kuo)(kuo)徑導線(xian)(xian)也就是(shi)擴(kuo)(kuo)大導線(xian)(xian)外徑技術(shu)，當線(xian)(xian)路的(de)(de)電壓(ya)超過220kv時，為了降低(di)線(xian)(xian)路電抗和電暈損耗，通常采用(yong)(yong)擴(kuo)(kuo)徑導線(xian)(xian)。擴(kuo)(kuo)徑導線(xian)(xian)就是(shi)把普通的(de)(de)導線(xian)(xian)做(zuo)(zuo)成中(zhong)(zhong)空（里面用(yong)(yong)多股芯線(xian)(xian)和支撐層(ceng)做(zuo)(zuo)成）或者減(jian)少其中(zhong)(zhong)部分層(ceng)單(dan)線(xian)(xian)數(shu)量(liang)(liang)（使該層(ceng)單(dan)線(xian)(xian)間存在一(yi)定(ding)數(shu)量(liang)(liang)空隙(xi)），最終達到增加導線(xian)(xian)的(de)(de)等效半徑的(de)(de)目的(de)(de)。

交(jiao)流(liu)輸電(dian)(dian)線(xian)(xian)路(lu)的(de)(de)(de)電(dian)(dian)暈(yun)損失主要(yao)與導(dao)(dao)(dao)(dao)線(xian)(xian)表面場強(qiang)和天氣有關，根據(ju)絕緣水(shui)平要(yao)求(qiu)確定(ding)了相(xiang)間距(ju)離后(hou)，導(dao)(dao)(dao)(dao)線(xian)(xian)表面場強(qiang)主要(yao)與導(dao)(dao)(dao)(dao)線(xian)(xian)分(fen)裂(lie)數、分(fen)裂(lie)間距(ju)和 子導(dao)(dao)(dao)(dao)線(xian)(xian)直(zhi)徑(jing)有關，分(fen)裂(lie)數越(yue)多，子導(dao)(dao)(dao)(dao)線(xian)(xian)直(zhi)徑(jing)越(yue)大， 表面場強(qiang)越(yue)小(xiao)。擴徑(jing)導(dao)(dao)(dao)(dao)線(xian)(xian)通過支(zhi)撐(cheng)鋁(lv)線(xian)(xian)疏繞的(de)(de)(de)方(fang)式 擴大了導(dao)(dao)(dao)(dao)線(xian)(xian)外徑(jing)，這樣(yang)可減(jian)小(xiao)導(dao)(dao)(dao)(dao)線(xian)(xian)表面的(de)(de)(de)電(dian)(dian)場強(qiang)度和電(dian)(dian)暈(yun)放電(dian)(dian)，降低(di)噪聲，減(jian)少對無線(xian)(xian)電(dian)(dian)的(de)(de)(de)干擾。相(xiang) 對于常規(gui)導(dao)(dao)(dao)(dao)線(xian)(xian)，擴徑(jing)導(dao)(dao)(dao)(dao)線(xian)(xian)重(zhong)量較輕(qing)，安裝(zhuang)敷設后(hou)的(de)(de)(de) 塑(su)蠕伸長減(jian)小(xiao)，導(dao)(dao)(dao)(dao)線(xian)(xian)永久(jiu)變形減(jian)少，在滿足輸送容 量要(yao)求(qiu)和環境保護指標(biao)的(de)(de)(de)前(qian)提(ti)下，可大幅降低(di)線(xian)(xian)路(lu) 整體造(zao)價。簡單說來，擴徑(jing)導(dao)(dao)(dao)(dao)線(xian)(xian)是從常規(gui)導(dao)(dao)(dao)(dao)線(xian)(xian)中抽取數股 鋁(lv)線(xian)(xian)后(hou)繞制而成的(de)(de)(de)，是常規(gui)導(dao)(dao)(dao)(dao)線(xian)(xian)時升(sheng)級進化品。