金属化膜电容器自愈理论及规律研究  

Study on Theory and Influence Factors of Self-Healing in Metallized Film Capacitors

作　　者：李化[1] 章妙[1] 林福昌[1] 陈耀红[1] 吕霏[1] 李智威[1] 彭波[2] 

机构地区：[1]华中科技大学强电磁工程与新技术国家重点实验室,武汉430074 [2]湖南省电力公司科学研究院,长沙410007

出　　处：《电工技术学报》2012年第9期218-223,230,共7页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金青年基金资助项目(50907028)

摘　　要：主要研究金属化膜电容器的自愈特性及影响自愈过程的关键因素。研究表明,降低自愈放电过程中的自愈能量,是提高金属化膜电容器工作寿命和可靠性的有效途径。通过分析金属化膜自愈的物理过程,采用电测量法对影响自愈过程的各种参数及其相关性规律进行研究。对方阻R>30/□的金属化膜,在场强200V/m时开始出现击穿并发生自愈,在600V/m附近时击穿概率达到80%,电容器在高场强下工作可靠性降低。自愈面积与自愈持续时间随着自愈能量的增加而增加,自愈能量与电压的二次方成正比、与方阻的二次方成反比,采用高方阻金属化膜可有效降低电容量损失,提高电容器寿命。层间压强增大,自愈能量减小,自愈面积和自愈持续时间减小,在这种情况下,电弧易熄灭,降低了电容量损失,提高了电容器工作可靠性。The paper mainly studies the self-healing characteristics and its key influencing factors of metallized film capacitors. The research first indicates that the reduction of self-healing energy is the effective way to improve the lifetime and the reliability of the capacitors. The main influencing factors on self-healing process are studied by physical analysis and electrical parameter measurement. For the metallized film capacitor with sheet resistance above 30Ω/□： ①The breakdown and self-healing event begin when the electric field is 200V/μm. And the probability of breakdown increases to 80% when the electric field is 600V/μm. Thus the reliability of the metallized capacitors would decrease under high electric field. ②The demetallized area and duration time increases with the increasing self-healing energy. Self-healing energy is proportional to the second power of working voltage and is inversely proportional to the second power of sheet resistance. Using metallized film with high sheet resistance, the capacitance loss could decrease and the lifetime of the capacitors could increase. ③The self-healing energy decreases with larger inter-layer pressure with a consequence of smaller demetallized area and shorter duration time. In such condition, the capacitance loss and the reliability of the capacitors could be reduced and enhanced.

关 键 词：金属化膜电容器 自愈能量 自愈概率 自愈持续时间 自愈面积 寿命 

分 类 号：TM533.3[电气工程—电器]