10 kV透明电缆终端典型缺陷局部放电特征研究

Partial Discharge Characteristics of Typical Defects in 10 kV Transparent Cable Termination

为研究电缆终端典型缺陷的局部放电(PD)特征差异,本研究设计了适用于实验室观测的透明电缆终端,并在终端内预制刀痕缺陷及半导体突起两种常见缺陷。首先利用COMSOL有限元软件对刀痕及半导体突起两种缺陷进行建模与电场仿真;然后搭建10 kV透明硅橡胶终端电热老化试验平台以模拟真实工况并加速老化,利用高频电流传感器(HFCT)获取典型缺陷下的局部放电数据,并构造二维放电谱图;最后对不同电缆终端缺陷的PD信号进行对比分析,并结合仿真结果说明刀痕缺陷及半导体突起缺陷的电场分布特征差异。结果表明:采用透明硅橡胶终端可以实现对电缆终端典型缺陷的连续观测;相比刀痕缺陷,半导体突起缺陷内的电场畸变更严重,其绝缘劣化速度更快。

In order to study the partial discharge(PD) characteristics difference of typical defects in cable termination, a transparent cable termination suitable for laboratory observation was designed, and two kinds of typical defects, the cutting defect and the semiconductor protrusion defect, were prefabricated in the termination. Firstly, the cutting defect and semiconductor protrusion defect were modeled and their electric fields were simulated by COMSOL finite element software. Then an electrical-thermal ageing test platform for 10 kV transparent cable termination was set up to simulate the real condition and accelerate ageing, the PD data of the typical defects was extracted by high frequency current transformer(HFCT),and the two-dimensional discharge spectrogram was constructed. Finally, the PD signals of different cable terminal defects were compared, and the difference of electric field distribution characteristics between cutting defect and semiconductor protrusion defect was illustrated with simulation results. The results show that the transparent silicone rubber termination can realize the continuous observation on the defects in cable termination. Compared with the cutting defect, the electric field distortion in the semiconductor protrusion defect is more serious, and its insulation deterioration rate is faster.