硅橡胶绝缘材料温度及场强依赖特性对XLPE绝缘直流电缆预制接头内电场分布的影响  

Effect of temperature and field strength dependence characteristics of silicone rubber insulating material on electric field distribution in prefabricated joints of XLPE insulated DC cables

作　　者：赵明伟 马天祥 李丹 张拓 ZHAO Mingwei;MA Tianxiang;LI Dan;ZHANG Tuo(Electric Power Science Research Institute of State Grid Hebei Electric Power Co.,Ltd.,Shijiazhuang 050021,China)

机构地区：[1]国网河北省电力有限公司电力科学研究院,河北石家庄050021

出　　处：《绝缘材料》2024年第12期58-65,共8页Insulating Materials

基　　金：国家电网有限公司科技项目(kj2021-003)。

摘　　要：由于电缆接头在直流运行下的电场分布受绝缘材料电导率影响,而电导率受温度与电场的影响并呈现非线性特性,故接头内电场分布变得异常复杂。为选择或确定适合工程应用的接头绝缘材料,改善接头内的电场分布,本文针对10 kV电压等级XLPE绝缘直流电缆预制接头结构构建仿真模型,通过改变硅橡胶的电导非线性特征参数,探究接头运行在满载运行状态下硅橡胶的电导活化能及电导场强依赖特性对接头内电场分布的影响。结果表明:高负载情况下,接头绝缘交界面处的直流稳态场强受绝缘材料电导活化能及电导场强依赖特性的影响,其中电导活化能的影响更大。从经济性角度考虑,硅橡胶与XLPE绝缘材料的电导活化能与电导场强依赖系数之比分别为应不高于0.94和不低于0.50。The electric field distribution of cable joints under DC operation is influenced by the conductivity of insulating materials,which exhibits non-linear characteristics under the effects of temperature and electric field,so the electric field distribution within the joints is exceptionally complex.In order to select or determine suitable insulating materials for joint in engineering applications and improve the electric field distribution inside the joint,we constructed a simulation model for the prefabricated joint structure of 10 kV voltage level XLPE-insulated DC cables.By changing the non-linear characteristic parameters of the conductance of silicone rubber,the influence of the conductance activation energy and conductance field strength dependence of silicone rubber on the electric field distribution inside the joint under full load operation was explored.The results show that under high load conditions,the DC steady-state field strength at the insulation interface of the joint is influenced by the conductance activation energy and the conductance field strength dependence of the insulating material,the conductance activation energy has a greater impact.From an economic perspective,the ratio of the conductance activation energy and field strength dependence coefficient of conductance between silicone rubber and XLPE insulating material should not be higher than 0.94 and not be lower than 0.50,respectively.

关 键 词：硅橡胶 电缆预制接头 电场分布 非线性电导 

分 类 号：TM215[一般工业技术—材料科学与工程]