Recurrence plot analysis to estimate the surface erosion on polymeric insulating materials

Polymeric insulators are used for high voltage transmission and distribution systems due to their advantages over traditional ceramic/glass insulators. However, these insulators encounter various stresses in the service condition. CIGRE working group D1.14 has identified twelve important parameters for the evaluation of polymeric outdoor insulation materials. Tracking/erosion is an important parameter for the evaluation for long term performance. In the present work, experiments on polymeric insulators to thermal erosion are conducted, fourier transform infra-red (FTIR), scanning electron microscopy (SEM) are used to study the surface chemical and morphological changes and surface roughness measurements are done using 2D profilometer. Results obtained from thermal erosion experiments show severe de-polymerization and loss of hydrophobicity. An attempt has been made to evaluate the polymeric insulating materials using recurrence plot (RP) analysis. Recurrence plot analysis of discharge current sequence confirms, a discharge process is prolonged as the number of drops containing contaminants is increased. Quantitative indicators of RP analysis, recurrence rate (RR) and Determinism (DET) are used to evaluate the performance of various polymeric insulating materials used in the study.