Enhanced Single-Ended Fault Location in Hybrid Transmission Corridors with Underground Cable Sections Using a Dynamic Sequence Impedance Factor

Accurate fault location in hybrid transmission corridors combining overhead lines (OHL) and underground cables (UGC) represents a critical challenge for power system reliability. The industry-standard Takagi algorithm, in phase to ground failures, relies on a constant zerosequence compensation factor 𝑘 that is inadequate for representing the non-homogeneous nature of these mixed circuits, frequently leading to faulted section misidentification. This contribution presents a single-ended fault location method for single phase-to-ground faults that incorporates a dynamic, distance-dependent compensation factor 𝑘(𝑥). The algorithm iteratively evaluates the cumulative sequence impedances along the route, automatically adapting to the specific characteristics of each segment (whether OHL, UGC,…