Mechanical Defects and Pollution Patterns Drive Leakage Current Harmonics

⚡ AI Executive Summary

Researchers conducted laboratory tests on 20 kV composite insulators to understand how surface contamination, humidity, and mechanical damage interact to affect leakage current behavior. The study examined three pollution patterns—uniform, ring non-uniform, and ring-longitudinal non-uniform—alongside defects in different locations, revealing that central defects increased harmonic amplitudes significantly compared to undamaged samples. For power system operators, these findings suggest that insulator condition monitoring must account for the combined effects of contamination geometry and mechanical degradation, not pollution alone. The research indicates that harmonic signatures in leakage current could become a practical diagnostic tool for field asset management. Since composite insulators are critical to transmission and distribution reliability, the development of predictive models linking salt deposit density and contamination patterns to harmonic response offers utilities a pathway to earlier defect detection and planned maintenance scheduling, potentially reducing unplanned outages and improving grid resilience.