110kV XLPE电缆GIS内锥插拔式快速中间接头的设计

Design of Inner Cone Pluggable Intermediate Quick Joint for 110 kV XLPE Cables Based on GIS

故障快速修复目前高压交联聚乙烯电力电缆迫切需要解决和完善的问题。为缩短电缆故障时的抢修时间以及节约硬件成本,将电缆终端气体绝缘开关(GIS)技术创新化地运用到电缆中间接头上,开发出了一种用于110KV交联聚乙烯电缆或电缆接头在发生主绝缘故障后临时连接用的GIS内锥插拔式快速接头。利用有限元分析对接头的应力锥、高压屏蔽电极、附件材料电性参数的配合进行了优化设计,得出了最优配合,完成了接头样机的研制并进行了现场试验验证。结果表明:应力锥的轴向长度及端部半径最优值分别为135 mm和25 mm;应力锥与半导体屏蔽层的介电系数比值以及应力锥与主绝缘的电导率比值越小越好;高压屏蔽电极的倒角半径及电极长度最优值分别为10 mm及40 mm。使用设计的接头,可在4 h内完成电缆附件的安装。该接头可以实现异径电缆对接,通用性强,主体部分可以重复使用,满足系统的运行要求。

The rapid repair of faulted high-voltage XLPE power cable has become an urgent issue. To shorten the time of high-voltage power cables rejuvenation and save the cost of device, the gas switch gear （GIS） technology of cable terminal was applied to design intermediate joints for temporary cable connection when 110 kV XLPE cable or cable joints are in occurrence of insulation fault. Using a finite element model, we analyzed the stress cone, high voltage shielded elec- trode, and electrical parameter coordination, and obtained their optimized values accordingly. A sample joint was completed based on these parameters and tested by field experiments. The results show that the optimal values of axial length and edge radius of stress cone are 135 mm and 25 mm, respectively. Decreasing dielectric coefficient ratio of the stress cone to the shielding layer of semiconductor, as well as decreasing electrical conductivity ratio of the stress cone to the main insulation, is beneficial to the joint. The optimal values of fillet radius and electrode length are 10 mm and 40 mm, respectively. By using the proposed joint, the rejuvenation time of cable accessories was shortened to less than 4 hours. The cable joint with reduced cable butt can be realized, showing a strong versatility and re-usability of main portion of joint, which meets the operation requirements of system.