A Study on the Life-Time Assessment Ways and Various Failure Types of 154 kV Porcelain Insulators Installed in South Korea

In this study, we investigated 154-kV porcelain insulators with various failure types and discussed the causes of the failures. In South Korea, 1,223,538 154 kV porcelain insulators (produced by a foreign company) are in active service in 2017, installed in overhead power transmission lines. Among them, 797,659 (65.19%) have been used over 30 years in active service. Porcelain insulators employed in transmission lines need to exhibit a high electrical resistance, mechanical strength, stability, and ability to maintain satisfactory performance under various environments. In this study, a life-time assessment strategy is proposed for the 154 kV porcelain insulators according to the operational circumstances. The life-time extrapolation of porcelain insulators in 154-kV transmission lines is very challenging, owing to the complex aging process. As the first step of the life-time extrapolation, we characterized the failure types. Various factors such as temperature, rain, dust, acids, corrosion, vibrations, and mechanical and electrical stresses, over a long period of time can lead to various types of failures in porcelain insulators.