Fault Location in Distribution Networks Through Graph Marking

This paper presents an automatic method for locating faults based on the statuses of fault indicators that are telemetered to the distribution control center. The method constructs an undirected subgraph of the the part of the network that is relevant to the fault event; the vertices of this graph are areas that comprise the possibly faulted electrical equipment, and its edges are the fault indicators. Two graph marking approaches for fault location are discussed: a conventional marking approach that is adopted by the industry and an improved version of it, the downstream marking approach. This paper demonstrates that the downstream marking approach is superior to the conventional one, particularly in terms of immunity to fault indicators that fail to be set. Numerical results and comparisons are presented for unsymmetrical faults and on several networks.