This article discussed the deterioration of porcelain insulators which accounts for more than 50% of the maintenance costs in an accident event. We highlighted deterioration mechanisms and preventive methods to predict failure due to various pollutants such as Cl, NOx, SOx, CO2, temperature. Deterioration mechanisms have been organized for each component of the insulator. Galvanic corrosion occurs due to pollutants in the atmosphere. Corrosion occurs mainly in the metal part In the case of cement, alkali silica reaction (ASR) caused carbonation due to presence of carbon dioxide in the air, high hydrogen ion concentration and humidity conditions. The expansion of cement begins because of the reactive substance of silica. The main components of cement, CaO and Na+, K+ ion, are deteriorated in response to silica gel. Expansion can cause mechanical detachment. The deterioration of cement can be determined using a universal indicator. Degradation of insulation resistance occurs when contaminants are attached to the porcelain and may not reduce insulation resistance depending on the form of contaminant. When contamination begins, the degradation of insulation resistance begins rapidly when it becomes humidity is high.
展开▼
