超高直流电场作用下金属化膜电容器的老化特性  

Ageing characteristics of metallized film capacitor under ultra-high DC field

作　　者：徐哲 程璐 刘宏博 王镜然 马宇威 李志元 刘文凤[1] 国江 XU Zhe;CHENG Lu;LIU Hongbo;WANG Jingran;MA Yuwei;LI Zhiyuan;LIU Wenfeng;GUO Jiang(State Key Laboratory of Power Equipment and Electrical Insulation,Xi′an Jiaotong University,Xi′an 714009,China;State Key Laboratory of Power Grid Environmental Protection,China Electric Power Research Institute Co.,Ltd.,Wuhan 430074,China)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,陕西西安710049 [2]中国电力科学研究院有限公司电网环境保护国家重点实验室,湖北武汉430074

出　　处：《绝缘材料》2023年第5期55-62,共8页Insulating Materials

基　　金：国家自然科学基金资助项目(52107025);电网环境保护国家重点实验室开放基金资助项目(GYW51202101365)。

摘　　要：为揭示超高直流电场作用下金属化膜电容器的老化特性,对电容器设备及其介质材料进行了研究。基于电容器的实际运行工况,对特殊设计的电容器元件在60℃下分别开展了直流场强为0En、1.4En、1.5En与1.6En的老化试验。对老化中的电容器元件电容量和老化失效后的基膜(双向拉伸聚丙烯(BOPP)薄膜)进行测试。结果表明:电容器失效机理与老化电场有关,存在阈值电场。当老化电场低于阈值电场时,电容器发生长期失效,受到薄膜性能劣化的影响电容量降低,薄膜的电气强度随分子链段运动活化能的降低而降低;当老化电场高于阈值电场时,电容器发生短期故障,极高的电应力使薄膜介质原有的电弱点迅速击穿,自愈面积快速增大,设备寿命大幅缩短。In order to reveal the ageing characteristics of metallized film capacitor under ultra-high DC field,the capacitor and its dielectric material were studied.On the basis of the practical working conditions of capacitor,the special designed capacitor elements were conducted ageing tests at 60℃ under the DC field of 0En,1.4En,1.5En,and 1.6En,respectively.The capacity of the capacitor elements during ageing and the base film(biaxially oriented polypropylene(BOPP) film) after ageing failure were tested.The results show that the failure mechanism of the capacitor is related to the ageing electric field,and there is an electric field threshold.When the ageing electric field is lower than the electric field threshold,the capacitor will go through a long-term failure,and its capacitance decreases affected by the performance degradation of film,the electrical strength of the film decreases with the decrease of the activation energy of molecular segment motion.When the ageing electric field is higher than the electric field threshold,the capacitor will go through a short-term failure,and the extremely high electrical stress causes the original weakness to break down rapidly,the self-healing area increases rapidly,so the equipment life is greatly shortened.

关 键 词：金属化膜电容器 BOPP 直流电老化 

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]