Comments on “Minimizing the number of PMUs and their optimal placement in power systems” in 83 (2012) 66–72

Abstract This short communication is a discussion of the paper entitled “Minimizing the number of PMUs and their optimal placement in power systems” in 83 (2012) 66–72 introduced a new model for phasor measurement units (PMUs) placement in electric smart grids. The model incorporated some constraints which result a reduction in the number of PMUs with respect to the topological observability constraint. The authors stated that “ The results show that the number of PMUs is equal to or less than the corresponding results of recently published papers, while the system topological observability is complete, and measurement redundancy is increased ”. However, this conclusion cannot be deduced from the results given by the authors because proposed results of the IEEE 118-Bus test system are infeasible. This note mention an incompleteness in constraints presented in 83 (2012) 66–72 besides proposing a new observability function to resolve the aforesaid weakness.