WAVE REGIMES OF CREEPER ELECTRIC BREAKDOWN ON POLYMER SURFACES
Jae-Ou Chae, Young‐Sik Jeong · 1994
The creeper electric breakdown (CEB) is caused by low current discharges on humid and dirty surfaces of polymer plastic parts in electric fields. As a result of carbon channels, regular and dendritic carbonized structures grow on the polymer surface slowly and electric and heat transfer properties of the surface are broken. This phenomenon is important for automotive engineering because different kinds of polymer materials. are used for production and operation in strong electric fields and humid ambient atmosphere today. The experimental study of GEB's wave regimes was carried out. Main dependences of the growth velocity on the discharge current, configuration of electrodes, type of polymer, oxygen concentration in the ambient atmosphere, heat transfer conditions were found. In the case of dendritic regimes of the CEB, the fractal dimension (D) of the carbonized structures was found to be equal to 1.6 - 1.9. The average length (L) of structures increased according to the law L - tf , where t is the growth time and f = 0.55 - 0.7. The fractal dimension was connected with f by the equation f = 1/0.