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.