Noniterative Parameter-Free Fault Location for Practically Transposed Transmission Lines With Synchronized/Unsynchronized Measurements

This article proposes a noniterative parameter-free fault location (PFFL) method for practically transposed lines. First, the proposed method accurately models the nonhomogeneity and asymmetry of practically transposed transmission lines by incorporating three untransposed line segments according to the practical transposition principle. To reduce the modeling complexity and to enable noniterative closed-form solutions for fault location, each untransposed line segment is modeled using lumped impedances in matrix form, and the shunt admittances are introduced at both line terminals to enhance the modeling accuracy. Finally, the analytical solution of fault location is derived, avoiding the divergence risks from iterative algorithms. The line or system parameters are not required throughout the entire fault location procedure, and it is compatible with both synchronized and unsynchronized phasor measurements at line terminals. Numerical experiments confirm the necessity of the proposed method considering nonhomogeneity and asymmetry of practically transposed lines: the proposed method exhibits higher fault location accuracy compared to the existing parameter-free method that assumes the ideal transposition. Moreover, the robustness of the proposed method is validated by further testing cases.