Robust fault location for two and three terminal lines using synchronized phasor measurements

This paper introduces a robust fault location method that utilizes wide area phasor measurements and sparse estimation technique. The proposed method transforms the fault location problem into estimating sparse bus injections in the network, based upon the equivalence in the change of bus voltages between a fault current drawn at an arbitrary point along a line and virtual superimposed current injections at the terminal nodes of the same line. This equivalence not only works for two terminal lines but also three terminal lines. Assuming limited placement of phasor measurements, an underdetermined linear estimation problem whose solution is sparse will be formed. This problem can be solved via sparse estimation especially L1 regularization technique. Considering possible failure of individual measurement units, an extended formulation incorporating sparse error vector is used to increase the method's robustness. Extensive simulation results have verified the effectiveness of the proposed method.