摘要
XLPE绝缘电力电缆,特别是中压电缆在运行过程中可能产生水树枝等缺陷,并且进一步发展为电树枝,最终导致电缆击穿。除了常规的物理和化学评估方法以及在线监测等技术能够为电缆的状态评估和运行提供必要的判据,等温松弛电流法作为一种具有丰富物理内涵的方法也已经在国外的XLPE电缆老化状态以及寿命的评估方面发挥积极的作用。对目前国内外电缆评估的方法进行了简略的分析,着重介绍了等温松弛电流法的原理。在详细分析欧美等多个国家对等温松弛电流法老化状态评估的关键参数——老化因子A的基础上,初步研究了国产电缆在未老化的初始状态的老化因子以及热老化后的老化因子的变化。研究表明国产电缆在未老化时期老化因子就大于国外电缆的。论文初步分析了出现该现象的原因,为等温松弛电流法在我国的应用提供了必要的基础。
Power cable insulated with XLPE is developed in past 40 years and also widely used in China in the past 30 years. However, some defect, such as water tree, may grow in XLPE insulation of medial voltage cable. Furthermore, theses water tree could develop as electrical tree at extreme high electric field, leading to accidents such as breakdown. Some assessment criterion could be provided with the method based on physics, ehemistry and line monitoring technology. The status of power cable could be assessed with these criterions, isothermal relaxation current （IRC） is a non-destructive method applied in other countries. Some valuable information related with insulation status could be acquired with this method, in this paper, the general evaluation methods used in power cable are introduced, especially the theory of IRC. Criterions of aging fact A based on IRC theort in other eountry are introduced. Moreover, the aging fact A for unaged and aged cable produced in China is investigated for comparison with the value in other eountry. it seems that the value of aging fact A for unaged cable is lager than that value provided by other eountry. Some probably reasons for these phenomenons are discussed, which could provide neeessary foundation for the application of IRC method in China.
出处
《电线电缆》
2014年第1期34-37,共4页
Wire & Cable
关键词
交联聚乙烯电力电缆
老化评估
等温松弛电流法
老化因子
判据
XLPE electric power cable
aging accession
thermal relaxation current method
aging factor
criterion
