聚乙烯中水树枝-电树枝的相互转化

Mutual Transformation of Water Tree and Electrical Tree in PE

通过合适的手段模拟水树枝存在情况下材料中的电场强度分布,对理解水树枝向电树枝的转化和评估水树枝的危害程度有重要的实用价值。在总结水树枝-电树枝相互转化已有研究成果的基础上,用有限元方法模拟了不同半径水树枝存在情况下材料中的电场分布。模拟结果表明:水树枝存在的情况下,材料中的最大电场强度出现在水树枝尖端;在外施电压一定的情况下,材料中的最大电场强度随水树枝半径的增大先减小后增加;较短的水树枝弱化了材料中的局部电场强度。

In order to extend power cable lifetime,it is important to clarify the influencing factors and inception and propagation mechanisms of water tree transformed from electrical tree.The water tree dimensions dependent internal electric field profiles are investigated by using finite element method.The numerical analysis results show that maximum electric field strength exists at the tip of water tree,demonstrate that the maximum electric field strength first decreases and then increases with increasing water tree radius when the applied voltage is invariant,and indicate that partial electric field strength is weakened in the early stage of water tree.