An Electrical Capacitance Tomography System for Insulation Defects Detection in Power Cables

Monitoring the insulation status of power cables is important for ensuring their safe and stable operation. The electrical capacitance tomography (ECT) technique, characterized by noninvasion, simple structure, and fast imaging speed, holds great potential in the detection of cable insulation defects. In this study, a novel ECT system for insulation defects detection in power cables has been developed. A flexible eight-electrode capacitive sensor was built and mounted on the surface of cable insulation. The resolution of the measurement circuit was tested as $7.97\times 10^{-{3}}$ – $5.10\times 10^{-{1}}$ fF, and the isolation degree of excitation channels was as high as −71.3 dB. Finally, an insulation defects detection platform for cross-linked polyethylene (XLPE) cables was established to validate the detection and imaging capability for air-gap insulation defects in cables.