The incorporation of sophisticated sensing technology, notably the phasor measurement units (PMUs), offers tremendous opportunities toward real-time dynamic state monitoring in the smart grid. With a view to effectively exploiting the potentials of these advanced and non-conventional sensing resources, this paper is concerned with the design of PMU placement and sampling methodologies that optimize the state estimation performance in the face of infrastructure and communication limitations. Specifically, on the qualitative front, the paper addresses the minimal placement requirement (measured in terms of the minimal number of sensing units to be deployed) that guarantees dynamic system observability, and explicitly characterizes the desired placement configuration(s) that ensure such observability. Simulation studies performed on the IEEE 5-bus system (with 37 dynamical state components) demonstrate the effectiveness of the proposed approach.
