An Improved Natural Frequency Based Line Fault Location Method on Untransposed Lines

Accurate fault location method reduces power outage time and operational costs. In this paper, a novel natural frequency based fault location method is proposed for untransposed transmission lines. The new method is without the assumption that the transmission line is geometrically symmetrical by reconstructing the new phase to model transformation matrix. The connections of mode networks during faults with the new transformation matrix are also derived, to ensure validity of the fault location method. Numerical experiments prove that the proposed fault location approach presents higher fault location accuracy compared to existing natural frequency based fault location method during phase faults with different fault types, locations and impedances.