摘要
特高压直流输电工程的实施使得特高压直流电缆装备的需求日渐迫切。为研究特高压直流电缆接头的结构设计,从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入手,分析改性硅橡胶对特高压直流电缆接头绝缘结构优化设计的影响。结果表明:直流电缆接头增强绝缘中电场强度会随着电缆负荷电流的增大而发生极性反转。掺杂的钛酸铜钙纳米纤维无机填料大幅增强了硅橡胶的电导率非线性,提高了硅橡胶的活化能和电场强度系数参数,降低电导率进入非线性区的阈值电场强度。改性硅橡胶增强绝缘材料明显抑制特高压直流电缆接头中的双层介质界面切向电场、应力锥和高压屏蔽管表面电场的畸变。采用改性硅橡胶作为特高压直流电缆接头增强绝缘材料,可弥补调整电缆接头结构尺寸仍不能有效抑制接头中电场畸变的不足。研究结果可有效解决特高压直流电缆接头设计中的电场控制难题。
It is increasingly urgent to the demand of ultra-high voltage direct current(UHVDC) cable equipment because of the implementation of UHVD transmission project. In order to study the structural design of UHVDC cable joints, we start from the influence of nonlinear conductivity characteristics of polymer insulation materials on the insulation electric field distribution of DC cable joints to analyze the effect of modified silicone rubber on the optimal design of the insulation structure of UHVDC cable joints. The results show that the electric field in the reinforced insulation of DC cable joints will reverse polarity with the increases of the cable load current. The nonlinear conductivity of the silicone rubber is greatly enhanced by doping copper calcium titanate nanofibers inorganic filler, the activation energy and electric field strength coefficient of the silicone rubber are improved, and the threshold electric field strength of conductivity entering the nonlinear region is reduced. The distortion of tangential electric field of double-layer dielectric interface and surface electric field of stress cone and high-voltage shielding tube 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 results can effectively solve the electric field control problem in the design of UHVDC cable joints.
作者
刘宗喜
欧阳本红
赵鹏
陈铮铮
赵健康
LIU Zongxi;OUYANG Benhong;ZHAO Peng;CHEN Zhengzheng;ZHAO Jiankang(State Grid China Electric Power Research Institute,Wuhan 430072,China)
出处
《绝缘材料》
CAS
北大核心
2021年第8期74-82,共9页
Insulating Materials
基金
国家电网公司科技项目(SGSHDK00SPJS1800273)。
关键词
特高压直流电缆接头
聚合物绝缘
非线性电导率
改性硅橡胶
绝缘结构优化
UHVDC cable joint
polymer insulation
nonlinear conductivity
modified silicone rubber
insulation structure optimization
