Aging of porcelain suspension insulators under mechanical andelectrical stress on EHV AC lines

摘要

A small number of failures of standard porcelain suspensioninsulators used on American Electric Power Company's (USA) 765 kV lineswere found with the porcelain shed broken away from the cap and pinassembly, allowing a “donut” of porcelain to fall to thehardware below. The investigation of these failures was approached frommany angles to determine the sequence of events leading to the failure.Additionally, it was desired to determine if this phenomena was theresult of aging porcelain under electrical and/or mechanicalstress