Defect Detection and Recognition of Insulation Pull Rod Based on the Ultrasonic Method

During the manufacturing process, the insulation pull rod will inevitably cause internal defects, resulting in partial discharge or breakdown. The detection of internal defects before putting into operation can effectively reduce the occurrence of the above situation. Ultrasonic method is considered to be an effective method to detect internal defects because of its high efficiency, large depth and high sensitivity. However, the research on defect type identification is not clear. In this paper, in order to identify different internal defects of insulation pull rods, the ultrasonic spectrum analysis method is used to study the internal defects of artificial insulation pull rod defect samples and non operating insulation pull rods. Firstly, the artificial defects are detected to study the spectral characteristics of ultrasonic echo, and then the non operating insulation pull rods are detected. The ultrasonic echo signals of the detected defects are processed by spectrum analysis and the characteristic values are extracted. It is found that the internal crack and white spot defect can be distinguished according to the eigenvalue, which is of great significance to guide the manufacturing of insulation pull rod and improve its operation reliability.