154 / 2018-08-25 16:44:46

Investigation of Plasma Treatment on Surface Flashover Characteristics of Epoxy

Surface Flashover;,Epoxy,Plasma

In this study, epoxy resin specimens treated with air plasma for different times (1min, 2min, 3min, 4min, 5min) were prepared to investigate the effect of plasma treatment on surface properties, such as surface chemical structure, trap parameters , surface conductivity and their influences on surface flashover performances. Contact angle measurement is used for characterizing surface free energy property which could indicate chemical structure changes in surface layers. The results show that contact angle decreases with the increasing treating time, which is considered to be caused by inducing hydrophilic group into the surface of the specimens. Surface potential decay (SPD) is used to study surface trap parameters which demonstrates that with the increase of plasma treatment time, shallow trap level and density increases first and then decreases, in contract, deep trap level decreases first and then increases, and the turning points for both of them appear at 4min. Surface conductivity increases quickly when the treatment time is less than 4min and then decreases. DC surface flashover performances of specimens present obvious changes with plasma treatment time, which shows that with the prolonging of treating time surface flashover voltage increases first and then decreases with increasing processing time, and the highest value appears at 4min. Finally, the mechanism of surface plasma treatment on vacuum surface flashover is discussed, which is considered to have relationship with surface conductivity and trap distribution.