Accurate Fault Location for Untransposed/Transposed Transmission Lines Using Sparse Wide-Area Measurements

This paper presents a new approach for locating short-circuit faults on untransposed transmission lines. Various fault-location algorithms have been proposed previously for transposed lines, which may not always be the case in practice. Existing methods usually require measurements recorded from one or two terminals of the faulted line, which may not be always available. To complement existing methods, this paper proposes a novel, general fault-location method for untransposed lines using sparse wide-area measurements, which is also applicable to transposed lines. Phasor measurement units are utilized to obtain the sparse wide-area synchronized measurements, which may be captured from buses far away from the faulted line. This method fully considers inherent unbalances of untransposed lines, and fully models shunt capacitances of lines based on a distributed parameter line model. Optimal estimation theory is exploited to make the most of available measurements for enhanced estimation. The method is able to locate faults on single-circuit and double-circuit line configurations, and is immune to fault resistances. Another feature of this method is that it does not require the fault type to be known. Extensive simulation studies using the Electromagnetic Transients Program have been performed, and quite accurate results have been achieved.