Generalized observability analysis and measurement classification

Network observability analysis is formulated in a way to incorporate the conventional as well as unconventional measurements, including line currents. This formulation has two essential advantages over the existing methods of network observability analysis: (1) it detects not only unobservability but also uniqueness of the observed state, and (2) it can directly identify the unobservable or nonuniquely observable branches without having to remove the irrelevant injections in an iterative manner. In addition, unlike the numerical observability analysis methods proposed so far, it can readily identify residual spread components and critical measurements. The proposed formulation is implemented and tested on sample power systems.