Defect localization and severity assessment of cable shielding layer based on broadband impedance spectroscopy

Abstract To solve the problem of locating and assessing the degree of damage to the cable shielding layer, this paper proposes a method based on broadband impedance spectra (BIS) for locating and evaluating cable shielding layer damage. Firstly, a distributed parameter model of the cable is established based on transmission line theory, and the BIS at the cable’s input end with a damaged metal shielding layer is obtained through finite element simulation. Then, the BIS is processed using discrete Fourier transform to obtain the location spectrum, and the Taylor window function is used to enhance the spectrum for accurate location of the shielding layer damage. Next, Gradually increasing damage to the copper shield layer was created on both a 13.4-meter-long XLPE cable and a 10-meter-long SYV50-12 coaxial cable to validate the feasibility and accuracy of the method in practical applications. Finally, a method for assessing the degree of cable shielding layer damage based on measured data is proposed and verified. Simulation and experimental results show that this method can accurately locate defects in the cable shielding layer and assess their degree of damage with a good level of accuracy.