ILP-Based Optimal PMU Placement with the Inclusion of the Effect of a Group of Zero-Injection Buses

Zero-injection buses (ZIBs) can reduce the number of phasor measurement units (PMUs) required to be installed for complete observability. It has been demonstrated that a group of neighboring ZIBs can further reduce this required number of PMUs. In contrast to a single ZIB, the effect of a group of ZIBs has not been incorporated into the model of optimal PMU placement (OPP) using mathematical approaches, except for some heuristics methods. In this paper, a novel methodology to incorporate the effect of a group of ZIBs into the OPP model is proposed, using the integer linear programming approach. Two common contingencies-line outage and PMU loss-are also considered. Moreover, two visualization techniques are used for illustrating the locations of PMUs obtained from OPP: (1) using a graph-based force-directed method and (2) on a map using the geographic information system. The proposed method is verified using several small- and large-scale test systems and compared with other related studies.