高压方波脉冲对聚酰亚胺薄膜表面形貌的影响

为了研究高频脉冲电压下绝缘材料的老化、失效机理,给变频电机绝缘结构设计提供理论基础,在高频脉冲方波条件下,对纳米和非纳米聚酰亚胺薄膜进行了不同频率和不同时间的老化及局部放电测试:通过扫描电镜研究对比了老化对2种薄膜表面及横截面形貌的破坏情况;分析比较了频率对2种薄膜局部放电参量(起始放电电压,平均放电量和放电次数)的影响。结果表明:老化后2种薄膜的表面形貌都发生了明显改变,但由于添加纳米粒子使2种薄膜破坏情况完全不同;气隙表面电导率对局部放电有很大影响,无机纳米填充使非纳米聚酰亚胺薄膜产生大量界面,改善了材料的电导率,更加容易产生局部放电初始电子。

Influence of Continuous Square Impulses Voltage on Surface Shape of Polyimide Film

To investigate the aging and failure mechanism of insulation materials under high-frequency impulse,the test of electrical aging and measurement of partial discharge is performed on nanometer hybrid polyimide film and non-nanometer polyimide film with different frequency and different aging time under high-frequency square impulse.The destroy instance of polyimide film's surface is studied by SEM and some parameters of PD are discussed based on measurement results.The results show that after aging,the surface shape of two kinds of polyimide film is changed distinctly,but the destroy instance is completely different.Gap surface conductivity has greater impact on PD,the interfaces formed by inorganic nano-filler filling improve the conductivity of the material,the movement of charge along the gap surface becomes much easier,meanwhile,large quantities of shallow traps existed in nano-materials make it easier to engender the PD initial electronic selection.