Detecting Impedance and Shunt Conductance Faults in Lossy Transmission Lines

Abstract

We describe a method that uses propagation measurements to reconstruct the spatial profiles of the distributed impedance and shunt conductance parameters of a lossy transmission line. From these reconstructed spatial profiles, we can deduce the presence and location of transmission line faults. The method makes use of return loss measurements from both ends of the transmission line as well as the transmission loss between the two ends. An inverse scattering approach based on the Born approximation is utilized to obtain the reconstructions. Its advantage compared to exact formulations, such as those based on the Zakharov–Shabat equations, is that it provides separate analytical expressions for the individual spatial profiles of the distributed impedance and shunt conductance transmission line parameters. It is shown by simulation and experiment that the method performs well in a variety of configurations and has the potential to be used in fault detection for cables and feed networks.