Visual Platforms for Ultrasonic Detection of the Stress in GIS/GIL Insulators

Stress concentration may be an important cause for mechanical strength deterioration of GIS/GIL insulators. Ultrasonic detection technology of stress has the advantages of good directivity, nondestructive and high efficiency. In this paper, three kinds of LabVIEW visual detection platforms are designed. One is the platform of ultrasonic longitudinal wave penetration, which is used to detect the stress of epoxy in three-post insulators. One is the platform of ultrasonic longitudinal wave reflection, which is used to detect the stress of epoxy outside grounding insert of three-post insulators. The last one is the platform of ultrasonic critical refraction longitudinal wave, which is used to detect the surface stress of basin insulators. Taking a 550 kV GIL three-post insulator and a 252 kV GIS basin insulator as the research objects, the ultrasonic detection for stress of insulators is carried out. It is found that the stress of epoxy in a post of the three-post insulator is −0.008 MPa. The stress of epoxy outside grounding insert of the three-post insulator is −0.007 MPa. The surface stress of the basin insulator is 0.423 MPa when no external load is applied. The platforms can be used to detect the stress of insulators conveniently and quickly, which provides the foundation for subsequent engineering applications of the stress detection on GIS/GIL insulators.