Low-Resolution Fault Localization Using Phasor Measurement Units with Community Detection

Abstract

A significant portion of the literature on fault localization assumes (more or less explicitly) that there are sufficient reliable measurements to guarantee that the system is observable. While several heuristics exist to break the observability barrier, they mostly rely on recognizing spatio-temporal patterns, without giving insights on how the performance are tied with the system features and the sensor deployment. In this paper, we try to fill this gap and investigate the limitations and performance limits of fault localization using Phasor Measurement Units (PMUs), in the low measurements regime, i.e., when the system is unobservable with the measurements available. Our main contribution is to show how one can leverage the scarce measurements to localize different type of distribution line faults (three-phase, single-phase to ground, ...) at the level of sub-graph, rather than with the resolution of a line. We show that the resolution we obtain is strongly tied with the graph clustering notion in network science.

Phasor Measurement Units Optimal Placement and Performance Limits for Fault Localization

“…Preliminary results about the algorithm and error analysis were presented in the conference paper [1]. Additional contributions include:…”

“…• Formulating an optimal PMU sensor placement strategy that was mentioned as future work in the conference version of [1], • Presenting results by running fault localization and optimal placement algorithms on data from a real distribution grid, • Integrating the proposed fault localization method in the cyber-physical intrusion detection architecture developed by the authors in [27], and show how such a methodology can be used to detect intrusions on fault detectors. Paper organization: Section II describes the fault localization problem along with the formulation of the corresponding hypothesis testing problem to distinguish between faults at different locations.…”

“…From (1), I 0 = YV 0 and when the measurements have stabilized during fault, I F + I E = YV F where V F is the post-fault voltage 1 . By subtracting the pre-fault current from the post-fault current provides the equation:…”

“…x, in which x is a sparse vector (i.e. the vector I E 1 The assumption is that the post-fault data is recorded before any corrective protection measure is taken so that the admittance matrix stays the same. reordered) whose non-zero entries point to the sites of the fault.…”

“…Any opinions, findings, conclusions, or recommendations expressed in this material are those of the authors and do not necessarily reflect those of the sponsors of this work. Preliminary version of this work was published in the proceedings of 2018 IEEE SmartGridComm [1].…”