A new fault location scheme for parallel transmission lines using one-terminal data

This paper proposes a fault location (FL) scheme for a two-terminal double-circuit transmission line using one-terminal current and voltage measurements. As the proposed scheme is formulated in the phase-coordinates, the parallel transmission lines are not required to be decoupled, and the proposed scheme can be applied for transposed or untransposed lines. In addition, the proposed scheme takes into account the line asymmetry and the potential couplings between the phases of the same circuit or different circuits. The derived FL equation is based on two concepts. The first concept is that the fault impedance is mainly resistive component. The second one is that the voltages of the similar phases in both circuits at each line terminal are equal to each other. Further, a new fault classification method is introduced to recognize the faulted phases, which are initially required to apply the proposed FL scheme. Moreover, the IEEE 39-bus system is deployed as a test case, and it is simulated on PSCAD/EMTDC software. The frequency-dependent phase model is used to emulate the parallel transmission lines. All fault types, including the cross-circuit faults, are tested considering different fault resistances and locations. In addition, the effect of the measurement errors on the fault location accuracy is investigated.