Broadband Impedance Spectroscopy Analysis Model for Cross-Bonded Cable Systems

Power cable systems usually use cross-bonded to reduce the induced voltage and sheath currents in the metal shield. As the number of cable lines put into operation and the number of years of operation continues to increase, it brings many challenges for operation and maintenance work. The diagnosis method based on broadband impedance spectroscopy can quickly and accurately detect local defects in power cable systems, and improving the reliability of power cable systems. In this paper, a broadband impedance spectroscopy analysis model of major cross-bonded system segment will be established based on the transmission line theory. By solving frequency domain transmission line equations, the broadband impedance at the near end of a cross-bonded cable system is derived by using the segmentation and superposition methods with the boundary conditions. When using broadband impedance spectroscopy to locate defects in power cable systems, the model can determine the location of both the cable joints and defects by transforming from the frequency domain to the spatial domain.