结晶状态对XLPE电缆绝缘中电树枝的影响

The Influence of Crystalline State on Electrical Tree in XLPE Cable Insulation

实验发现一种生长于 XL PE电缆绝缘试样中、完全不同于已发表的多数电树枝的“藤枝状”电树枝 ,从其发展方向上的突变性、扩展性和非电场依赖性结合对材料结晶状态的分析表明 ,这是一种在残存应力协同作用下生长于大晶块界面无定型区的晶界电树枝。其根本原因是大晶块界面的杂质和微孔 。

It is found in this paper, there is a kind of electrical tree with shape of 'bine-branch' like in XLPE cable insulation. It has a very special shape that is different from most shapes of trees that have been published. It has growing properties in unexpected developing direction for single branch, growing does not follow the direction of electrical field flux, and growing is toward more broad area than other kinds of electrical trees. It is found by analyzing the crystalline state that this is a kind of electrical tree growing along big crystal boundary under survival mechanical stress. The basic reason for development of bine-branch electrical tree is impurity and micro-holes between big crystals and amorphous region of XLPE. The mechanism for this kind of development of electrical tree is partial discharge combined with partial high temperature and partial high gas pressure.