Phasor-Based Double-Ended Method for Fault Location on N-Circuit ‎Transmission Lines ‎

Existing double-ended fault location methods in transmission systems can be applied only to single or ‎double-circuit transmission lines. They conventionally use different abc-domain or sequence network ‎equivalent circuits for different fault types. Furthermore, some methods do not consider shunt ‎capacitances of the line, inductive or capacitive coupling between different phases, and (or) the cases of ‎untransposed lines, simultaneously. In this paper, a comprehensive and fast phasor-based double-ended ‎fault location method is proposed which can be used for N-circuit transmission lines. For this purpose, first, ‎a matrix-vector equivalent circuit (MVEC) is proposed that leads to a unique formulation for fault location ‎problem regardless of fault type, number of line circuits, being transposed or untransposed while it ‎considers inductive and capacitive coupling between the phases. Then, based on the MVEC formulation, a ‎bi-level algorithm is suggested that quickly finds the fault location, despite its iterative nature. The ‎proposed method does not need to know impedances of local and remote end sources. Furthermore, its ‎accuracy is not sensitive to fault impedance. Various case studies in terms of fault types, fault impedances, ‎and distances from the measurement side in the presence of noise reveal the accuracy and applicability of ‎the proposed fault location method.‎