Leakage current patterns on contaminated polymeric surfaces

This paper presents measurements of low-level leakage current (LC) patterns on naturally aged insulators and artificially contaminated material samples as well as insulaton. A nonlinear behaviorof the LC has been observed. Possible causes for this behavior are discussed and its relations to surface hydrophobicity and electric stress are described. In addition, neural networks are trained to recognize the LC patterns as well as to estimate their harmonic contents.