Surface flashover of atmospheric-pressure plasma treated PMMA in transformer oil

Solid-liquid interface surface flashover in transformer oil is an important factor affecting the insulating performance of dielectric. Improvement of surface flashover performance is a key issue, and has attracted intensive attentions these years. In this paper, plasma jet is used for a hydrophilic treatment and dielectric barrier discharge is used for a hydrophobic modification in order to improve the surface insulating performance of polymethylmethacrylate (PMMA) in transformer oil. The experimental results show that the surface flashover voltage of the hydrophilic treated PMMA (water contact angle 35°) and the hydrophobic treated PMMA (water contact angle 90°) will increase by about 35 kV compared to that of the untreated PMMA.