基于OWTS 10kV XLPE电缆终端半导电层制作缺陷的实验研究

在10 kV XLPE电缆终端及接头安装过程中,如果半导电层的制作不当将会导致局部电场的畸变,最终会导致终端及接头的击穿故障。笔者对电缆终端剥除了铜屏蔽层、半导电层后的结构构建了电路模型。通过对模型的解析分析证明了XLPE与半导电层交界面电场同其周边介质类型以及介质倾斜角α有关。使用有限元仿真软件分3组情形对交界面综合场强及其切向分量进行仿真计算。仿真结果表明在半导电层右端涂抹倾斜角α=6°的硅脂效果最好。在分析OWTS实验原理基础上,对终端半导电层无倒角缺陷电缆进行了实验。实验结果表明,OWTS能够有效地检测出半导电层制作不当该类缺陷,并对其实验步骤进行总结。

Experimental Analysis of the 10 kV XLPE Cable Terminals with Defects Based on OWTS

Distortion of local electric field is easy to be induced by the defects of semi-conductive layer at 10 kV XLPE cable terminals,leading to breakdown fault in the process of cable terminal/connector installation.In this paper,a circuit model of the cable terminal is constructed after stripping the shielding layer and semi-conductive layer.The analysis of the model illustrates that the electric field of the interface between XLPE and semi-conductive layer is related with the inductivity of surrounding media and the inclination angle α.The horizontal and vertical electric fields of three parameter sets are simulated by the finite element simulation software.The results show that the electric field is perfect when the angle α is about 6°.The cable terminals without chamfered semi-conductive layer are tested by OWTS on the basis of analysis of the experimental principle,and the results demonstrate that OWTS can detect defect type of semi-conductive layer effectively.