SiC改性提升聚酰亚胺薄膜直流耐电晕性能的机理  

Mechanism of Improving DC Corona Resistance of Polyimide Films by SiC Modification

作　　者：王健[1] 熊沛琪 侯程志 张淑敏 刘继奎[2] 李庆民[1] WANG Jian;XIONG Peiqi;HOU Chengzhi;ZHANG Shumin;LIU Jikui;LI Qingmin(State Key Lab of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China;Beijing Institute of Control Engineering,Beijing 100089,China)

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,北京102206 [2]北京控制工程研究所,北京100089

出　　处：《高电压技术》2024年第4期1655-1663,共9页High Voltage Engineering

基　　金：国家自然科学基金(52177140,92266109)。

摘　　要：传统聚酰亚胺(PI)薄膜应用到更高电压等级设备中,易产生电晕放电甚至绝缘失效。为提升聚酰亚胺薄膜耐电晕能力,实验采取碳化硅(SiC)作为增强相对PI基体相进行改性,探究SiC改性对复合薄膜耐电晕特性的影响机理。实验结果表明,随着SiC含量增加,SiC/PI复合薄膜出现非线性电导特性并逐渐增强,其同步提升的浅深陷阱密度比与载流子迁移率促进了表面电荷消散速率的增加。同时,SiC提升了15 kV直流电压下薄膜的沿面闪络和击穿时间,其中质量分数25%SiC/PI复合薄膜较纯PI膜分别提升了416.28%和298.39%。这是因为增强的非线性电导率和表面电荷消散速率,有利于空间和表面电荷运输,减少电场畸变,从而提升复合薄膜的耐电晕能力。对电晕损伤薄膜的无损区、圆状白斑区和白色堆积区进行形貌观测,发现SiC颗粒会在等离子体碰撞下形成放电阻挡层,有效减少电晕对基体相的侵蚀,延长了复合薄膜的耐电晕时间。最后发现质量分数15%SiC/PI复合薄膜为综合耐电晕与力学特性下的最优选择。When traditional polyimide(PI)film is applied to higher voltage equipment,it is easy to generate corona discharge or even insulation failure.In order to improve the corona resistance of the polyimide film,SiC was used as a reinforcing phase to modify the PI matrix in the experiment,and the mechanism of the effect of SiC modification on the corona resistance of composite films was explored.The experimental results show that,the nonlinear conductivity of SiC/PI composite films increase with the increase of SiC content.And the simultaneous increase of shallow-deep trap density ratio and carrier mobility promotes the increase of surface charge dissipation rate.At the same time,SiC improves the flashover and breakdown time of films under 15 kV DC voltage,in which the 25%SiC/PI composite film is enhanced by 416.28%and 298.39%,respectively,compared with the pure PI film.The reason is that the enhanced nonlinear conductivity and surface charge dissipation rate are beneficial to the space and surface charge transport and reduce the electric field distortion,thus improving the corona resistance of the composite films.Next,the morphologies of the non-destructive area,round white spot area and white accumulation area of the corona-damaged films were observed.It is found that,SiC particles will form a discharge barrier layer under the plasma collision,which can effectively reduce the erosion of the matrix phase by corona and prolong the corona resistance time of composite films.Finally,it is found that,15wt%SiC/PI composite film is the best choice under the combination of corona resistance and mechanical properties.

关 键 词：聚酰亚胺薄膜 耐电晕 碳化硅 电荷 电晕损伤 力学特性 

分 类 号：TQ323.7[化学工程—合成树脂塑料工业] TB383.2[一般工业技术—材料科学与工程] TM215[电气工程—电工理论与新技术]