AFM Analysis and Fractal Characteristics Extraction of the Surface Morphology of Epoxy Resin After Vacuum Flashover
Xie Qing1, Fu Kexin2, Lu Lu1, Liang Shaodong1, Huang He1, Lü Fangcheng2
1. Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense North China Electric Power University Baoding 071003 China; 2. State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources North China Electric Power University Beijing 102206 China
Abstract：A systematic and accurate description to the surface morphology of insulating materials helps to obtain a better understand of the damage effects of discharge on the material surface. It is essential to explore the relationship between the surface morphology and flashover characteristics. In this paper, vacuum flashover experiments were conducted on epoxy resin under different electric fields. Then, the surface morphology of the samples under different damage degrees and discharge regions was investigated by atomic force microscopy (AFM), and fractal theory was utilized to quantitatively analyze the morphological features. The results show that the sample surfaces sequentially experience the shape of sting, granule, peak, and continuous mountain during the four stages of damage process, and the surface roughness increases constantly in the process. In addition, the impact of flashover driven by highly non-uniform field on the surface morphology is more significant. Furthermore, the surface morphology of samples has fractal characteristics. The fractal dimension and multifractal parameters can be used to quantitatively characterize the complexity of the surface morphology as well as the height distribution of the surface. It is also found that the surface insulating strength decreases after flashover treatment, and the insulating performance is related to the surface roughness as well as the fractal parameters of the dielectric surface.
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2017, Vol. 32 
