Non-destructive ultrasonic measurements of ceramic post insulators used in electricity distribution systems

The authors present a new non-destructive ultrasonic method for investigations of long-rod insulators operating on station isolating switches. The 110/6kV stations are used in operating the field of domestic industrial power engineering. The main aim of research was to establish a close correlation between the degree of defectiveness of electrotechnical porcelain and the parameters of ultrasonic wave propagation and attenuation. In addition, the causes of breakage of insulator type SWZPAK-110 since 1975 were ascertained. This ceramic element underwent detailed structural and comparative acoustic measurements. The experimental investigations were performed using a specially designed and constructed measuring equipment. Besides establishing the original causes of breakage of the above mentioned insulator, the most significant achievement of work was the elaboration of the methodology of ultrasonic measurements applied directly to objects in rise on site. The presented method was also used for analysis of quality of a group of 43 insulators after long-term use on isolating switches.