基于非线性电导绝缘的随桥敷设高压直流电缆接头电-热场分布及优化设计  

Electrical-thermal Field Distributions and Optimal Design of Bridge-along HVDC Cable Joints Based on Nonlinear Conductive Insulation

作　　者：李捍平 丛贇 李小炳 张振鹏 刘勇 LI Hanping;CONG Yun;LI Xiaobing;ZHANG Zhenpeng;LIU Yong(Zhoushan Power Supply Company,State Grid Zhejiang Electric Power Co.,Ltd.,Zhoushan 316000;China Electric Power Research Institute,Wuhan 430074;School of Electrical and Information Engineering,Tianjin University,Tianjin 300072)

机构地区：[1]国网浙江省电力有限公司舟山供电公司,舟山316000 [2]中国电力科学研究院有限公司,武汉430074 [3]天津大学电气自动化与信息工程学院,天津300072

出　　处：《电气工程学报》2022年第2期226-234,共9页Journal of Electrical Engineering

基　　金：国家自然科学基金资助项目(51707133)。

摘　　要：针对随桥敷设高压直流电缆接头绝缘电-热场分布问题,开展基于非线性电导增强绝缘的高压直流电缆接头电场优化设计方法研究,探究电-热-机械应力多物理场作用下聚合物绝缘材料的非线性电导率特性对直流电缆接头绝缘电场分布的影响规律,分析高压直流电缆接头增强绝缘优化设计方法。结果表明,碳化硅(Silicon carbide,SiC)掺杂大幅增强了硅橡胶绝缘的非线性电导率,提高了硅橡胶绝缘的非线性系数参数,降低了非线性电导率的阈值电场强度。当桥梁梁箱温度达到40℃时,直流电缆满载运行条件下电缆接头最大场强位于应力锥根部,达到40 kV/mm;非线性电导复合绝缘可显著降低中间接头应力锥三结合点处电场强度,抑制附件增强绝缘的电场畸变。采用非线性电导硅橡胶绝缘作为高压直流电缆接头增强绝缘材料,可弥补电缆接头应力锥无法有效抑制接头绝缘直流电场畸变的不足。研究结果可为随桥敷设高压直流电缆接头绝缘电场调控与设计提供理论与试验基础。Aiming at the uniform distribution of electric-thermal coupling field in the HVDC cable joints laying along bridges, the electric field of HVDC cable joints is optimized and designed based on nonlinear conductive insulation in this paper. The influence of the non-linear conductivity characteristics of polymer insulating materials on the distribution of the insulation electric field of DC cable joints under the multi-filed of electrical, thermal and mechanical stress is studied, and the optimization design for the reinforced insulation of HVDC cable joints is analyzed. The results show that the nonlinear conductivity of the silicone rubber is greatly enhanced by doping silicon carbide(SiC) nanofillers, the electric field strength coefficient of the silicone rubber insulation are improved, and the threshold electric field strength of conductivity entering the nonlinear region is reduced. When the ambient temperature in the bridge beam box reaches 40℃, the maximum field in the cable joint is up to 40 kV/mm, located at the root of stress cone. The distortion of electric field of stress cone in the UHVDC cable joint are obviously suppressed by the modified silicone rubber reinforced insulation material. The modified silicone rubber, used as the reinforced insulating material for UHVDC cable joints, can make up for the insufficient that the field distortion in the joint cannot be suppressed effectively by adjusting the structural size of cable joints. The research can play an import role in the electric field modification and design of bridge-along HVDC cable joints.

关 键 词：随桥敷设电缆 直流电缆接头 聚合物绝缘 非线性电导 电热复合场 

分 类 号：TM215[一般工业技术—材料科学与工程]