Non Intrusive Detection of Ceramic Disc Punctures in Outdoor Insulator Strings

Insulator failures can significantly impact the reliability and integrity of the electric grid. Consequently, conducting routine condition assessments of outdoor insulators is crucial to mitigate the risk of premature failures. Internal defects such as punctures present a considerable challenge in detection, as the insulator’s exterior may present a misleading impression of integrity despite suffering from a permanent loss of insulation strength. This paper introduces a novel non-intrusive approach to detect punctured ceramic discs within an insulator string. The proposed method utilizes the directional characteristics of an ultrasonic sensor to achieve precise and accurate detection by monitoring induced surface discharges on adjacent healthy discs.