Selection of Methods and Standards for the High-Voltage Testing of Polymer Insulators

This paper emphasizes the importance of using polymer insulators. Evidently, polymer insulators have higher electrical insulating characteristics, better manufacturability in the production of structures of complex shapes, small dimensions, and the possibility of significant mechanical strengthening of insulating composite systems. Consequently, the proportion of polymers used in high-voltage technology is constantly growing. This study presents the general characteristics of high-voltage tests of polymer insulators, and the most hazardous defects occurring in the structures under consideration are identified. The key influence of partial discharges under long- and short-term application of voltage is noted, and an analytical relationship is established between the long- and short-term electrical strength of cast polymer insulation. The “life curves” of cast epoxy insulation on exposure to industrial frequency voltage are discussed for insulation with and without partial discharges. The necessary justifications and calculations were performed to determine the normalized values of the test voltage and the time of its exposure, considering the main possible defects in polymer insulators. This study introduces proposals for clarifying the methods and standards for high-voltage testing of polymer insulators.