Outdoor insulators: overview of in-service experience, inspection practice and future challenges

This paper, as a keynote contribution, provides an overview of the issues and challenges of applying ceramic and polymer insulators from a perspective of close academic cooperation with electrical utilities and insulator manufacturers. For polymer insulators, electrical stress, close to end fittings and across insulator leakage, remains an important design parameter. Also, for polymer insulators, methods for diagnosing the progress of aging and in-service degradation in response to excessive stress are presented. Future challenges in the life cycle cost of insulators, starting with harmonization of standards and ending with methods for recycling, are also outlined.