傅德舟 ， 郑飞虎 ， 安振连 ， 张冶文
电子与信息工程学院，同济大学，上海，210804
关键词：聚丙烯薄膜; 瞬态放电电流法空间电荷
中图分类号：TM211 文献标识码：A
摘要：本文提出了利用过阻尼瞬态放电电流法监测聚丙烯薄膜中空间电荷密度及其演变的方法。本文研究中首先将聚丙烯薄膜置于40ºC烘箱中并在直流电场下极化，极化结束后立即把聚丙烯薄膜串联至含有负载电阻和电感的线路中，同时测量聚丙烯薄膜的短路放电电流。通过比较不同极化电场强度对聚丙烯薄膜过阻尼放电电流波形特性的影响，分析计算得出薄膜样品在放电过程中剩余空间电荷总量和平均电荷密度随时间的变化规律。结果表明，通过瞬态电流法估算获得的薄膜中的剩余电荷密度与热脉冲法测量获得的稳态空间电荷密度相近。因此，本文认为利用过阻尼瞬态放电电流法可以基本分析出聚丙烯薄膜中空间电荷的分布及变化情况，是一种相比于热脉冲法、激光光强调制法简单而有效的近似方法。
Dynamic Monitoring of Space Charge Density in PolypropyleneFilms Based on Fast-Discharge Current Method*
FU De-zhou, ZHENGFei-hu, AN Zhen-lian, ZHANG Ye-wen
Department ofElectrical Engineering, Tongji University, Shanghai 201804, China
key words:Polypropylene Film, Fast-DischargeCurrent Method, Space Charge
Abstract: A method to monitor the spacecharge density and the evolution of polypropylene film was proposed using Fast-DischargeCurrent Method. The polypropylene film is placed in the oven at 40 degreesCelsius and polarized under DC electric field. After polarization, thepolypropylene film was instantly connected in series to the short circuit thatcontains load resistance and inductance. Then the short circuit dischargecurrent of the polypropylene film was measured. By comparing the influence ofdifferent field strength on the damping discharge current waveform characteristicsof polypropylene film, the rule was attained that the remaining amount of spacecharge and average charge density vary with time of thin film samples. Theresults show that the residual charge density in the thin films estimated bythe Fast-Discharge Current Method is similar to that of the steady state spacecharge density measured by the Thermal Pulse Method. Therefore, it is inferredthat the distribution and change of space charge in polypropylene film can beanalyzed by using the Fast-Discharge Current Method,which is a simple andeffective approximation method compared to the Thermal Pulse Method and LaserIntensity Modulation Method.