高场强下金属化膜电容器绝缘电阻特性

Insulation resistance characteristics of metallized film capacitor under high electric field

分析了高电场强度下金属化膜电容器绝缘电阻的特点,得出高电场强度下金属化膜电容器绝缘电阻是电容器介质膜泄漏和自愈过程的综合反映。针对高场强下的应用条件提出一种金属化膜电容器绝缘电阻的测试方法,并对高场强下电容器的绝缘电阻进行测试。测试结果表明:在300～400V/μm工作场强范围内金属化膜电容器绝缘电阻随工作场强增大会急剧减小,由于自愈的作用,绝缘电阻下降幅度随场强增加会逐渐变缓;在20～50℃工作温度范围内,金属化膜电容器绝缘电阻随温度升高会急剧减小,同样由于自愈的作用,绝缘电阻下降幅度随温度增高会逐渐变缓。分析得出,高温高场强下金属化膜电容器介质膜泄漏将会导致电容器电压出现明显下降,影响电容器和脉冲功率系统的储能效率。

This paper analyzes the insulation resistance characteristics of metallized film capacitor under high electric field,and shows that the insulation resistance is the comprehensive result of the dielectric leakage and self-healing under high electric field.An insulation resistance testing method is presented for the high metallized film capacitors under high electric field.The test results indicate that,for operating electric field ranging from 300 to 400 V/μm,the insulation resistance decreases rapidly with the electric field increasing,but because of the self-healing,the decrease gradually slows down.The insulation resistance follows similar rules within the operating temperature range of 20 to 50 ℃.In addition,the dielectric leakage under high operating temperature and electric field reduces the capacitor voltage significantly,affecting the energy storage efficiency of the capacitors and pulsed power systems.