Understanding treeing phenomena and space charge effect in gamma-irradiated XLPE cable insulation
Understanding treeing phenomena and space charge effect in gamma-irradiated XLPE cable insulation
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DOI：
10.1007/s00202-011-0205-7
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发表时间：
2011-04
影响因子：
1.8
通讯作者：
R. Sarathi;A. Nandini;Toshikatsu Tanaka
中科院分区：
文献类型：
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作者：
R. Sarathi;A. Nandini;Toshikatsu Tanaka
在本工作中，在交流电压下，在原始和γ辐照的交联聚乙烯电缆绝缘中实验产生了电树。在伽玛辐照的标本中，从缺陷部位形成纤维状的电树结构。采用威布尔分布分析了电气树的故障次数。研究结果表明，伽玛辐照的标本，在树木繁殖率高的地方，导致绝缘的早期失效。采用脉冲电声发射（PEAE）技术对交联聚乙烯电缆绝缘中空间电荷的形成进行了研究。研究结果表明，在伽马辐照的交联聚乙烯电缆绝缘中，在电极附近会形成同种和异质电荷。分析了不同电压量级下空间电荷密度随时间的变化。观察到，当异质电荷出现时，绝缘材料中的电场变得高度不均匀。在去除外加电压的情况下，经γ辐照的样品的电荷衰减较小。基于本研究，可以得出绝缘材料中的空间电荷密度与由于电树形成的绝缘材料的寿命呈反比关系。
In the present work, electrical trees were experimentally generated in virgin and gamma-irradiated XLPE cable insulation, under AC voltages. Fibrillar type of electrical tree structure forms from the defect site in gamma-irradiated specimens. Failure times due to electrical trees were analysed by adopting Weibull distribution studies. The results of the study indicate that gamma-irradiated specimens, where the rate of tree propagation is high, causing early failure of insulation. Pulsed electro acoustic emission (PEAE) technique was adopted to understand the space charge formation in XLPE cable insulation. The results of the study indicate that homo and hetero charges form near to the electrodes especially in gamma-irradiated XLPE cable insulation. Variations in space charge density at different voltage magnitudes with time were analysed. It is observed that the electric field in the insulating material becomes highly non-uniform on occurrence of hetero charges. It is also realized that on removal of applied voltage, the charge decay is less with gamma-irradiated specimens. Based on the present study, it could be concluded that Space charge density in insulating material and life of insulating material due to electrical tree formation shows inverse relationship.