电热力耦合下金属化膜自愈数值仿真  

Numerical Simulation of Self-Healing in Metallized Films under Electro-Thermo-Mechanical Coupling

作　　者：王泽 刘靖舟 王伟[1] 吴致远 齐红斌 Wang Ze;Liu Jingzhou;Wang Wei;Wu Zhiyuan;Qi Hongbin(Beijing Key Laboratory of High Voltage&EMC 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市重点实验室,北京102206

出　　处：《电工技术学报》2024年第S1期127-140,共14页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划资助项目(2021YFB2401503)。

摘　　要：金属化膜电容器因具有稳定性高、容量大、自愈性能好等特点,在许多电力电子领域中被广泛采用。研究复杂应力下金属化膜自愈微观机理,有助于优化金属化膜电容器制造工艺,提高产品寿命和稳定性。该文搭建了多物理场下金属化膜自愈特性测试平台,展开不同电热力环境下金属化膜自愈试验,表征了自愈面积与自愈形貌,并搭建了多物理场下自愈模型。仿真和试验结果表明:气态与等离子环境下的放电通道形成时间仅为ns级,发展形式与电子崩相似,且放电通道完全贯穿所需的时间与电压和温度成反比,与压强成正比;金属层蒸发面积和等离子化区域大小与施加的电压等级和温度成正比,与压强成反比,在不同电压、温度与压强下等离子化区域均占蒸发面积的43%左右;自愈过程中电介质层的炭化量极少,炭化区域半径和深度与电压、温度成正比,与压强成反比,炭化区域半径约为自愈面积半径的1.6倍,炭化深度约为膜厚的7%,仿真计算结果与相同条件下的自愈试验结果吻合。Metalized film capacitors are widely used in many power electronics fields due to their high stability,large capacity,and good self-healing properties.Studying the self-healing micro mechanism of metalized film under complex stress can help optimize the manufacturing process of metalized film capacitors,improve product lifespan,and stability.This article constructs a self-healing characteristic test platform for metalized film under multiple physical fields,conducts self-healing experiments under different electro-thermal environments,characterizes the self-healing area and morphology,In the experiments,a Nanyang MDP5.8 micrometer-thick polypropylene metalized film with an aluminum metal layer was used.The applied voltages on the samples were 1.8kV,2.3kV,2.8kV,3.3kV,and 3.8kV.The temperatures were set at 30,40,50,60,and 70°C,and the pressures were 1.8MPa,2.3MPa,8MPa,11MPa,and 15MPa.The self-healed samples were observed for morphology using an SOPTOP-SZN71 optical microscope.This article uses COMSOL MULTIPHYSICS 6.2 to build a self-healing model under multiple physical fields to explore the micro and macro characteristics of self-healing in metalized film.The article first used a bipolar carrier transport model to simulate the phenomenon of charge concentration in weak spots under continuous voltage stress during capacitor operation,calculating the distribution of charges within the material at different times.As charges accumulate,the equivalent current in the weak spot region gradually increases.Once it reaches a certain value,impurities within the metalized film first break down,leading to filamentary discharge within the region.At this point,the discharge channel transitions from solid-state to gaseous,and the simulation model shifts from a solid intrinsic carrier transport model to a gas discharge model.This model is constructed using the plasma model in COMSOL to investigate the effects of different electro-thermal environments on the formation and development of discharge channels.Finally,the electromagnet

关 键 词：金属化膜电容器 双极性载流子-运输模型 自愈模型 放电通道 等离子体 炭化 

分 类 号：TM215[一般工业技术—材料科学与工程]