大气相对湿度对聚酰亚胺薄膜表面电晕特性及老化过程的影响  

Effects of Ambient Relative Humidity on Surface Corona Properties and Ageing Process of Polyimide Films

作　　者：张晓琴 朱洪斌 余翔 李忠 李涵毅 任明[3] ZHANG Xiaoqin;ZHU Hongbin;YU Xiang;LI Zhong;LI Hanyi;REN Ming(State Grid Jiangsu Electric Power Research Institute,Nanjing 211100,China;Damo Tianyu Co.,Ltd.,Beijing 100086,China;Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]国网江苏省电力有限公司电力科学研究院,江苏南京211100 [2]大漠天宇有限公司,北京100086 [3]西安交通大学,陕西西安710049

出　　处：《绝缘材料》2021年第11期134-139,共6页Insulating Materials

基　　金：国家电网有限公司科技项目(J2020029)。

摘　　要：在不同的大气相对湿度(RH)下,聚酰亚胺薄膜的电晕耐受能力具有显著差异,为了掌握相对湿度对薄膜表面电晕特性及老化过程的影响,本文对不同RH下薄膜的电晕放电过程、电学变化及表面形貌进行跟踪监测,获得了RH对薄膜电晕老化的影响规律。结果表明:随着RH的升高,正、负半周放电活跃程度呈现相反的变化趋势;在RH≤69%时,放电量和放电频次随电晕时间表现为快速增长阶段、平稳阶段和二次发展阶段,当RH达到84%时,两者随时间呈线性增加趋势;薄膜含水量变化率(Δwt%)在电晕老化初期提高较为明显,而在中后期趋于平稳,当RH达到84%时,Δwt%随老化时间线性上升;分析表明,电晕放电对薄膜表面的电热损伤是表面电阻率(ρs)快速下降的主要原因,随着电晕侵蚀,水分缓慢渗入,最终导致体电阻率(ρv)的剧烈下降直至击穿。Under different environmental relative humidity(RH),the corona resistance of polyimide film presents significant differences.In order to understand the effects of RH on the surface corona characteristics and ageing process of film,we monitored the corona discharge process,electrical properties,and surface morphology of the film under different RH,and obtained the effects of RH on the corona ageing of film.The results show that with the increase of RH,the changing trends of the discharge activity at positive and negative half cycle are opposite.When the RH is equal or less than 69%,both the discharge quantity and discharge frequency show rapid growth stage,stationary stage,and secondary development stage with corona time,and when the RH attains 84%,both of them increase linearly with time.The changing rate of moisture content(Δwt%)of the film increases significantly at the beginning of corona ageing and tends to be stable at the middle and later periods,and when the RH attains 84%,theΔwt%increases linearly with the ageing time.It is analyzed that the surface electrothermal damage of film caused by corona discharge is the main cause of the rapid decrease of surface resistivity(ρs).With the corona erosion,water penetrate into the film gradually,eventually leading to the sharp decrease ofρv till breakdown.

关 键 词：聚酰亚胺薄膜 电晕老化 大气相对湿度 薄膜含水量 

分 类 号：TM215.3[一般工业技术—材料科学与工程]