绝缘老化对自熔式电缆中间接头界面电场及温度场分布的影响

Effect of Insulation Aging on the Distribution of Electric Field and Temperature Field at the Interface of Self-Melting Cable Intermediate Joint

自熔式电缆中间接头交联聚乙烯和三元乙丙橡胶绝缘老化,使其之间的界面性能发生劣化,为研究绝缘老化对复合界面处电场和温度分布的影响,以10 kV自熔式电缆中间接头为研究对象,采用COMSOL Multiphysics仿真软件建立仿真模型,分别计算了老化前后复合界面有无气隙时的电场和温度场分布特性。结果表明:自熔式电缆中间接头复合界面熔融接触时,复合界面处电场分布均匀,径向温度由内到外逐渐降低,符合热传导规律。绝缘老化前,复合界面存在气隙时,其电场与温度场均会发生严重畸变。绝缘老化后,界面处的电场及温度均有所增加,且气隙处的电场和温度上升更明显。

Ageing of crosslinked polyethylene and ethylene propylene diene insulation in self-melting cable joints causes deterioration of the interface properties between them.In order to study the influence of ageing on the electric field and the temperature distribution at the composite interface,a simulation model of a 10 kV self-melting cable intermediate joint was established by using COMSOL Multiphysics simulation software.The electric field and temperature field distribution characteristics of the composite interface with and without air gap before and after insulation ageing were calculated.The results show that the electric field at the composite interface is evenly distributed when the composite interface of the self-melting cable intermediate joint is completely fused.The radial temperature gradually decreases from the inside to the outside,which is in line with the law of heat conduction.When there is an air gap at the composite interface before insulation ageing,the electric field and temperature field will be significantly distorted.Besides,the electric field intensity and the temperature at the interface increase after insulation ageing,and the increase in electric field and temperature at the air gap is more pronounced.