中高压XLPE电缆故障种类及机理辨析

Analysis on The Fault Type and Mechanism of High-Voltage XLPE Cable

以设备故障的浴盆式曲线为主线,描述了中高压XLPE电缆的故障种类,并对其故障机理进行了剖析。归纳分析显示,XLPE电缆的初期故障主要为电缆附件故障,主要由附件安装缺陷、附件与电缆绝缘尺寸不匹配等引起,也包含绝缘材料缺陷所导致的电树枝击穿,以及安装未严格按设计要求进行所导致的电缆局部过热所引起的绝缘击穿事故;末期故障主因为绝缘老化,主要出现在电缆本体,如水树枝逐渐生长最终引起电树枝击穿等;导致中期故障的原因最难判别,因为中期故障可能出现在电缆的任何位置,而且导致故障的原因较多,如主绝缘的电树枝、水树枝老化、电缆外护套损伤导致局部过热,以及由于电缆附件橡胶绝缘老化导致回弹力下降所引发的电缆绝缘故障等。

Based on the TUB curve of the equipment failure as the main line, the fault types of high-voltage XLPE ca-ble is described, the failure mechanism is also analyzed in the paper. It shows that, the early failure of the cable is mainly of the accessories fault, this kind of failure include accessories install defects,the accessories and cable insula-tion installation size does not match, etc. Also contains the insulation defects that can certain initiation electrical tree-ing ,and also the cable breakdown accident caused by partial overheat because the cable installation does not accord-ing to the requirements of design. The reason that result in cable failure in late period of cable operation is mainly the insulation aging, such as the water tree initiation and grew eventually that cause the electrical treeing and insulation breakdown, etc. . The reason that causes middle period running fault of the cable is most difficult to be distinguished, because the middle period running fault not only may appear anywhere in the cable, and there are many factors that may lead to the failure, such as the electrical treeing and water treeing in main insulation of the cable, the local over-heating since cable outer sheath be damaged. Besides, there is a kind of cable accessories fault that is caused due to elastic force losses of the rubber insulation since it aging, etc.