A method for fault location using the phase difference of current in the protective layer at both ends of a cable section

This paper is based on the distribution characteristics of the protective layer current under the fault state of high-voltage cables, and discovers the monotonic variation law between the fault point position and the power frequency phase difference of the protective layer current at both ends of the cable fault section. A method for fault location using the phase difference of the protective layer current at both ends of the cable section is proposed. For a long cable line composed of multiple complete cross-connected sections, the cross-connected section can be located through the current power frequency phase difference P (section) at both ends of the metal sheath section, just like the section positioning within the complete cross-connected section. If P (section) ∈ (90°, 270°), then the section is a fault section; otherwise, it is a non-fault section. Finally, the relationship curve between the power frequency phase difference of the protective layer current at both ends of the fault section and the distance from the fault point is used to determine the fault location.