A Fault Location Method for Shielded Cables based on Coupling Characteristics

This paper describes a fault location method for shielded cables based on coupling characteristics that can be used to test the integrity of shielded cables nondestructively. A shield damaged coaxial cable and a wire are modelled which normally be used in aircraft cable bundles. The frequency domain coupling characteristic is affected which phase is related to the location of fault when the shield damage occurs. To infer calculate the coupling characteristics, Bethe theory is applied to a hole in the shield. Then by calculating phase of coupling signal using the signal flow network based on wave quantity, is the fault location is found. The method has a bandwidth of 300MHz-550MHz, a range of 1.5 m, and a resolution of 5 cm and can determine the fault location of shielded cables from measurements at a single end. The suggested method is validated by full wave simulation, and it is consistent with theoretical results, which indicate that the modeling and the method are correct. The effect of cable and mismatching losses limits the dynamic range of the measurement.