钛酸铜钙改性硅橡胶对500kV直流电缆接头优化设计关键控制参数的改善研究  

Research on Improvement of Key Control Parameters of Optimal Design of 500 kV DC Cable Joints by Calcium Copper Titanate Modified Silicone Rubber

作　　者：刘宗喜 欧阳本红 陈铮铮 赵鹏 LIU Zongxi;OUYANG Benhong;CHEN Zhengzheng;ZHAO Peng(China Electric Power Research Institute Co.,Ltd.,Wuhan 430072,China)

机构地区：[1]中国电力科学研究院有限公司,武汉430072

出　　处：《高压电器》2023年第10期153-161,共9页High Voltage Apparatus

基　　金：国家电网公司科技项目(52110418002P)。

摘　　要：采用硅橡胶作为超高压直流电缆接头的增强绝缘,在接头结构设计中需要解决硅橡胶与电缆绝缘的电导率配合和界面问题。文中利用钛酸铜钙纳米纤维(CCTO NFs)对硅橡胶进行非线性电导率的改性,对改性硅橡胶和交联聚乙烯(XLPE)组成的双层介质界面进行了直流击穿特性试验,以改性硅橡胶以及界面的特性参数为控制条件对改性硅橡胶500 kV直流电缆接头进行了优化设计分析。研究表明,CCTO NFs大大提高了硅橡胶的电导率非线性系数,CCTO改性硅橡胶的直流击穿强度随CCTO NFs体积分数的增加而下降,增大界面压力和涂覆硅脂可提高双层介质界面的直流击穿性能;这种改性硅橡胶对500 k V直流电缆接头增强绝缘中的过高的电场强度和应力锥根部的界面切向电场具有显著的改善作用,可进一步缩小500 kV直流电缆接头的几何结构。研究结果为500 kV直流电缆接头的优化设计提供了有效的新方法。When silicone rubber is used as the reinforced insulation for UHV DC cable joints,it is necessary to solve the electrical conductivity coordination and interface problems between the silicone rubber and the cable insulation in the joint structure design.In this paper,calcium copper titanate nanofibers(CCTO NFs)is used to modify the nonlinear conductivity of the silicone rubber.The DC breakdown characteristic test is carried out on the double-layer dielectric interface which is composed of modified silicone rubber and cross-linked polyethylene(XLPE).The optimized design and analysis of the modified silicone rubber 500 kV DC cable joints are carried out under the control conditions of the characteristic parameters of the modified silicone rubber and the double-layer dielectric interface.The research shows that CCTO NFs greatly improves the non-linear coefficient of conductivity of the silicone rubber,and the DC breakdown strength of CCTO of the modified silicone rubber decreases with the increase of CCTO NFs content.Increasing the interface pressure and applying silicone grease can increase the DC breakdown performance of double-layer dielectric interface.This modified silicone rubber can significantly improve the excessively high electric field strength in the reinforced insulation of the 500 kV DC cable joint and the interface tangential electric field at the root of the stress cone,and can further reduce the geometric structure of the 500 kV DC cable joint.The research results provide an effective new method for the optimal design of 500 kV DC cable joints.

关 键 词：钛酸铜钙 改性硅橡胶 直流电缆接头 关键控制参数 增强绝缘材料 界面切向场强 

分 类 号：TM75[电气工程—电力系统及自动化]