Artificial contamination test method on accumulated contamination conditions

According to the surveys on insulator contamination in heavily industrial contamination area, it is reported a quantity of contaminants on the insulator surface is greatly dependent upon the shed profile. Five years ago, a new approach named “dust cycle method”, including the evaluation of contamination accumulation performance by shed profile, was proposed by the Swedish Transmission Research Institute (STRI). A basic test equipment was made referring to this method, and contamination accumulation characteristics of suspension insulators (normal, fog, outer rib type) on heavily industrial contamination conditions were researched. Test results showed that salt deposit density (SDD) varied with humidity and wind velocity. In case of humidity of less than 70% and wind velocity of 3.5 m/s, SDD on bottom part of the outer rib type suspension insulator was about 10% of that of the fog type suspension insulator. This result is in good agreement with exposure test results. Furthermore, analysis of wind flow around the insulators suggested that outer rib type insulator had less SDD compared with fog type suspension insulators