Performance of thermoplastic elastomeric insulators under IEC 5000h multistress conditions

This work presents the results of an ongoing research on the performance of novel, environmentally-friendly thermoplastic elastomeric (TPE) insulators. 28 kV distribution class, dead-end insulators were used. The purpose of this research is to study the aging and degradation of this newly developed TPE insulators under long term stress. The insulators are exposed to slightly modified IEC 1109 5000 h multistress conditions. The various multistress conditions include UV radiation (1 mW/cm²), salt fog (16000 μS/cm conductivity), clear fog, rain (50-70 μS/cm) and heat (50°C). Two insulators, one vertical and one horizontal are used per IEC. Some of the IEC conditions were slightly modified in order to apply more realistic stresses similar to service environments. 2000 h aging showed slight color change, and some corrosion on end fittings. The aging and degradation is also quantified using electrical parameters and material diagnostic tests, such as FTIR and SEM.