摘要
根据从电树枝动态生长过程中所拍摄的大量实验照片和生长特性数据,探讨了在XLPE电缆绝缘中的电树枝发展特征与材料聚集态结构的关系。研究表明,由于半结晶高聚物不均匀聚集态、不均匀结晶和残存应力的影响,会在XLPE电缆绝缘中生成枝状、丛林状、藤枝状、松枝状和混合结构电树枝。并且在电树枝发展过程会呈现非常清晰的三个基本阶段,即引发阶段、滞长阶段和迅速发展阶段。引发阶段猛烈时生成迅速生长的纯枝状电树枝,引发阶段较弱或材料均匀时易导致丛林树状电树枝产生,发展于极不均匀区的电树枝多为鲜明的双结构;另外,引入一种新的参数,电树枝扩展系数来描述电树枝生长特性,并综合电树枝生长过程分形维数的变化规律和速度关系对产生这种实验现象的机理进行了分析。
According to experiment photographs and the growing characteristic datum that got from the growth process of the electrical tree, the relationship between electrical tree propagation characteristic and the material morphology in XLPE cable insulation are mainly studied. It is found that, as the influence of uneven congregating state, uneven crystal and survival stress in semi-crystalline polymer, there would be five kinds of electrical tree structures, which are branch, bush, bine-branch, pine-branch and mix configurations, developed in XLPE cable insulation. It is also found that there are three basic treeing propagation phases, which are initiation, stagnation, and rapid developing phases, presented in electrical tree developing process. If initiation phase is very violent, the pure branch tree will develop, but if this phase is faint, it is more easy to get a bush tree. There are would be a clear double structure of electrical tree when it grows at terribly uneven region. We introduce a new parameter, the expandingcoefficient to describe electrical tree propagation characteristic. Besides expanding- coefficient, another two coefficients： the dynamic fractal dimension and growing rate of the electrical tree are also used for analysis of the experiment phenomenon.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2006年第3期79-85,共7页
Proceedings of the CSEE
基金
国家自然科学基金项目(50577052)~~
