不同场强下金属化聚丙烯膜电容器泄漏特性

Leakage Characteristic of Metallized Polypropylene Film Capacitors under Different Electric Fields

金属化聚丙烯膜电容器(MPPFC)是脉冲功率电源系统中的常用储能单元,应用于高场强的MPPFC电压降落现象显著。介质泄漏是降低储能效率的重要因素,绝缘电阻提供了泄漏的路径。本文以MPPFC为对象,通过测量其的绝缘电阻来研究的泄漏特性。测试结果表明MPPFC的等效绝缘电阻对场强极其敏感,随着场强增加,等效绝缘电阻急剧减小。结晶度显著影响薄膜的等效绝缘电阻。结合Poole-Frenkel效应的等效绝缘电阻计算结果表明,影响等效绝缘电阻的关键参数是电场强度、电导率和Poole-Frenkel效应系数,本文等效绝缘电阻计算值与测试结果吻合。

The metallized polypropylene film capacitor（MPPFC） is one of the key components in pulsed power systems. The insulation resistance（IR） is one of the important factors resulting in the reduction of the capacitor energy efficiency in that it applies a current leakage path. This paper concentrates on the leakage phenomenon in the MPPFC by the measurement and analysis of the IR. The results indicate that the time constant（called equivalent IR） is extremely sensitive to the electric field and crystallinity Finally, theoretical calculation of equivalent IR based on the Poole-Frenkel effect match well with the experimental results.