温度对两种电缆绝缘材料介电参数影响的分析  

Analysis of the Influence of Temperature on the Dielectric Parameters of Two Types of Cable Insulation Materials

作　　者：李岩[1] 梁雨薇 宋浩源 甄冠成 刘晓坤 刘云鹏[1,2] Yan Li;Yu-wei Liang;Hao-yuan Song;Guan-cheng Zhen;Xiao-kun Liu;Yun-peng Liu(Department of Electrical Engineering,North China Electric Power University;National Key Laboratory of New Energy Power Systems(NCEPU),Baoding 071003)

机构地区：[1]华北电力大学(保定)电力工程系 [2]新能源电力系统国家重点实验室(华北电力大学),保定071003

出　　处：《高分子学报》2024年第12期1754-1762,共9页Acta Polymerica Sinica

基　　金：新能源电力系统全国重点实验室开放课题(项目号LAPS23016);中央高校基本科研业务费专项资金(项目号2024MS109)资助.

摘　　要：交联聚乙烯(XLPE)和油纸绝缘是重要的电缆绝缘材料,本研究旨在深入探讨温度对这2种材料介电性能的影响机制,以明确对其性能的具体影响.首先通过实验测量了25、35和45℃下XLPE和油纸绝缘的介电常数,研究结果显示,XLPE的相对介电常数随着温度的上升而呈现下降趋势.从25℃升至35℃时,其相对介电常数下降了0.28%;而从35℃进一步升高至45℃时,下降幅度为0.49%.相比之下,油纸绝缘的相对介电常数则随着温度的升高而增加.从25℃升至35℃,其相对介电常数增长了2.63%;而从35℃升至45℃,增长了1.73%.采用分子模拟对这一现象进行分析,构建2种材料的分子结构,利用偶极矩计算不同温度下材料的相对介电常数,仿真计算结果与实验结果吻合.为了进一步阐释介电常数随温度的变化规律,对2种材料末端距进行模拟分析,结果表明,在高弹态下,XLPE分子链末端距随温度升高而增大,这种变化阻碍了极化过程,导致介电常数降低.相反,在玻璃态的油纸绝缘中,极性材料绝缘纸的分子链末端距随温度升高而逐渐减小,极性运动加强,从而使得相对介电常数随之增加,这一发现从机理上解释了实验现象.Crosslinked polyethylene(XLPE)and oil paper insulation are both important cable insulation materials,and dielectric performance is a key parameter for measuring the state of insulation materials.Research has shown that temperature can affect the dielectric parameters of insulation materials,but the mechanism of temperature’s influence on the dielectric parameters of cable insulation materials is still not in-depth.To clarify the influence of temperature on the dielectric properties of different cable insulation materials,this article first measured the dielectric constants of XLPE and oil paper insulation at 25,35 and 45℃through experiments.It was found that the relative dielectric constant of XLPE decreased with increasing temperature,with a decrease of 0.28%from 25℃to 35℃and a decrease of 0.49%from 35℃to 45℃;The relative dielectric constant of oil paper insulation increases with temperature,increasing by 2.63%from 25℃to 35℃and 1.73%from 35℃to 45℃.Using molecular simulation to analyze this phenomenon,the molecular structures of two materials were constructed,and the relative dielectric constants of materials at different temperatures were calculated using dipole moments.The simulation results were consistent with the experimental results.To further explain the variation law of dielectric constant with temperature,simulation analysis was conducted on the end distance of two materials.It was found that the end distance of XLPE molecular chains in a high elastic state increases with temperature,hindering the polarization process and reducing the dielectric constant.The molecular chain end distance of insulating paper,a polar material in the glassy state of oil paper insulation,gradually decreases with increasing temperature,polar motion strengthens,and the relative dielectric constant also increases,explaining the experimental phenomenon from a mechanistic perspective.

关 键 词：交联聚乙烯 油纸绝缘 温度 介电参数 分子模拟 

分 类 号：TM21[一般工业技术—材料科学与工程] TQ325.12[电气工程—电工理论与新技术]