Research on Eddy Current Testing Technology for Lead Seal Crack Defects of High Voltage Cable

Because of the advantages of reliable sealing performance, high mechanical strength and good aging resistance, the lead seal of HV cable has been widely used in joint and terminal of HV cable. In order to ensure the safe and stable operation and improve service life of HV cable lines, it is necessary to carry out regular inspection and evaluation of lead seal state to reduce the potential safety hazards caused by lead seal crack. In this paper, the reasons leading to lead seal crack were analyzed. The common crack defeats testing methods were compared. The possibility of using eddy current testing technology to detect the crack of lead seal HV cable was verified by simulation using FEM software COMSOL, simulation test, on-site test, et al. The result shows that eddy current testing technology can effectively detect the lead seal crack defects of HV cables. And the impedance amplitude and phase change of the probe coil will be more obvious when the lead seal cracking is more serious.