電(dian)(dian)(dian)纜加上交流電(dian)(dian)(dian)壓(ya)，就有電(dian)(dian)(dian)流流過，當電(dian)(dian)(dian)壓(ya)的幅值(zhi)(zhi)和頻率一定時，電(dian)(dian)(dian)容電(dian)(dian)(dian)流的大小是正比于電(dian)(dian)(dian)纜的電(dian)(dian)(dian)容(Cx)。對于超高壓(ya)電(dian)(dian)(dian)纜，這種電(dian)(dian)(dian)容的電(dian)(dian)(dian)流可(ke)能(neng)達(da)到(dao)與額定電(dian)(dian)(dian)流可(ke)以相(xiang)比的數值(zhi)(zhi)，成(cheng)為(wei)限(xian)制電(dian)(dian)(dian)纜容量和傳輸距離(li)的重(zhong)要因素。因此電(dian)(dian)(dian)纜的電(dian)(dian)(dian)容也(ye)是電(dian)(dian)(dian)纜的主要的電(dian)(dian)(dian)性能(neng)參數之一。在(zai)交流電(dian)(dian)(dian)場中，電(dian)(dian)(dian)線電(dian)(dian)(dian)纜制造廠家(jia)，電(dian)(dian)(dian)纜中的絕緣體(ti)(ti)由于泄露電(dian)(dian)(dian)流和各種極(ji)化存(cun)在(zai)，會形成(cheng)介(jie)質(zhi)損(sun)(sun)耗，以介(jie)質(zhi)損(sun)(sun)耗因數或損(sun)(sun)耗角(jiao)正切值(zhi)(zhi)(TAN)來(lai)表示(shi)，電(dian)(dian)(dian)線，它不但浪(lang)費電(dian)(dian)(dian)能(neng)，而(er)且會使介(jie)質(zhi)(絕緣體(ti)(ti))發熱(re)，加速絕緣老化，因此TAN也(ye)是電(dian)(dian)(dian)纜主要參數之一。

怎樣保(bao)護電線(xian)電纜1，電絕(jue)緣管(guan)耐腐蝕性(xing)比(bi)較(jiao)好(hao)(hao)，可(ke)以有效的(de)使(shi)電線(xian)電纜的(de)使(shi)用(yong)(yong)壽命延長，適應各種環境(jing)。2，絕(jue)緣性(xing)較(jiao)好(hao)(hao)，具(ju)有阻燃、耐熱的(de)特性(xing)，可(ke)在(zai)130度高(gao)溫下長期(qi)使(shi)用(yong)(yong)而不變(bian)形。3，剛度韌(ren)性(xing)較(jiao)好(hao)(hao)，可(ke)直埋(mai)在(zai)行車道下不需要加混凝(ning)土(tu)作為(wei)保(bao)護層。4，電線(xian)電纜保(bao)護套管(guan)無論是管(guan)材(cai)還是管(guan)件都具(ju)有一定的(de)柔性(xing)，能(neng)抵御外界重(zhong)壓(ya)和基礎(chu)沉降(jiang)所引起(qi)的(de)破壞(huai)。5，具(ju)有良好(hao)(hao)的(de)抗信號干擾性(xing)能(neng)。6，電線(xian)電纜保(bao)護套內壁(bi)光滑，不會(hui)刮傷電纜。設(she)計采用(yong)(yong)承插式(shi)的(de)連接(jie)(jie)方式(shi)，方便安裝連接(jie)(jie)。接(jie)(jie)頭處(chu)加橡膠密(mi)封圈封即適應熱脹冷縮，又防止泥砂進(jin)入。

目前，隨著生產技(ji)術和生產工藝的(de)(de)(de)(de)不斷(duan)提高，交聯聚乙烯(xi)電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)已成為使(shi)用廣的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)產品，在電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)選(xuan)(xuan)型時，應(ying)(ying)根據使(shi)用的(de)(de)(de)(de)不同環境和條件，結合具體情況進(jin)行選(xuan)(xuan)擇(ze)，盡量減(jian)少穿越各種管邊(bian)鐵路，公路和通訊(xun)電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan);如采用直(zhi)埋和淺槽敷(fu)設方(fang)式時，應(ying)(ying)考慮使(shi)用加(jia)鋼鎧(kai)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)。對(dui)于電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)截面(mian)積的(de)(de)(de)(de)選(xuan)(xuan)擇(ze)應(ying)(ying)根據負荷預測結果，附近電(dian)(dian)(dian)(dian)線電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)廠，發展規劃，選(xuan)(xuan)擇(ze)合適的(de)(de)(de)(de)截面(mian)積，使(shi)電(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)纜(lan)(lan)(lan)滿足1大工作電(dian)(dian)(dian)(dian)流下的(de)(de)(de)(de)纜(lan)(lan)(lan)芯溫度(du)要求和電(dian)(dian)(dian)(dian)壓降要求，1大短(duan)路電(dian)(dian)(dian)(dian)流作用下的(de)(de)(de)(de)熱穩定要求。