金属化膜自愈过程的建模与仿真  

Modeling and simulation on self-healing process of metallized film

作　　者：齐红斌 吴致远 戴亚妮 刘尚书 刘靖舟 王伟[1] QI Hongbin;WU Zhiyuan;DAI Yani;LIU Shangshu;LIU Jingzhou;WANG Wei(Beijing Key Laboratory of High Voltage&Electromagnetic Compatibility,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学高电压与电磁兼容北京重点实验室,北京102206

出　　处：《绝缘材料》2024年第7期103-111,共9页Insulating Materials

基　　金：国家重点研发计划项目(2021YFB2401503)。

摘　　要：金属化聚丙烯膜电容器具有工作可靠性高、可自愈、低介质损耗等特点,然而其在工作过程中需要长期承受强直流电场和高温热场的联合作用,致使聚丙烯电介质薄膜内部容易积累空间电荷,导致其电气绝缘性能退化失效。本文搭建了金属化聚丙烯薄膜自愈模型,通过金属层蒸发模型研究不同自愈发展时间和外施电压下自愈点的自愈面积变化,并利用双极性载流子输运模型研究不同自愈发展时间、外施电压和温度下放电通道内的空间电荷密度变化,以此探究金属化薄膜自愈的微观机理。结果表明:金属化膜金属层蒸发面积与自愈发展时间呈现线性关系;随着外施直流电压和温度的升高,放电通道内部的电荷迁移过程加强,放电通道内部的电子和空穴更容易发生迁移并与相反极性的电荷发生复合;并且随着自愈过程的进行,注入放电通道中的电荷数量逐渐增多,电荷向放电通道两端迁移的行为加剧,造成放电通道内部的电势分布不均匀,放电通道内会发生电场畸变。Metallized polypropylene film capacitor has the characteristics of high reliability,self-healing,and low dielectric loss.However,it needs to withstand the combined action of strong direct current electric field and high temperature thermal field for a long time during the working process,which makes the space charge easy to accumulate inside the polypropylene dielectric film,resulting in the degradation of its electrical insulating properties.A self-healing model of metallized polypropylene film was established in this paper.The changes of self-healing area at the self-healing point under different self-healing development time and applied voltage were studied through the evaporation model of metal layer,and the changes of space charge density in the discharge channel under different self-healing development time,applied voltage,and temperature were studied by using the bipolar carrier transport model,so as to explore the microscopic mechanism of self-healing of metallized polypropylene film.The results show that there is a linear relationship between the evaporation area of metallized film and the self-healing development time.With the increase of the applied DC voltage and temperature,the charge migration process in discharge channel strengthens,and the electrons and holes in discharge channel are more likely to migrate and recombine with the charges of opposite polarity.With the self-healing process progresses,the charge amount injected into the discharge channel increases gradually,and the migration of charge to both ends of the discharge channel intensifies,resulting in uneven potential distribution in discharge channel and the electric field will distort in discharge channel.

关 键 词：金属化膜电容器 空间电荷 自愈面积 聚丙烯 双极性载流子 

分 类 号：TM215[一般工业技术—材料科学与工程] TM533[电气工程—电工理论与新技术]