Investigating singularities of the observability Jacobian for nonlinear power systems

This paper focuses on computing and interpreting the significance of the observability Jacobian singularities. Previous efforts have focused on developing an observability index and determining the effects of model/measurement changes to the observability formulation. Using this index, the singularities of the Jacobian are extracted, and preliminary results indicate that there is a duality between the loss of stability (whether it be phase or voltage stability), and the loss of observability. Thus, providing a single dual-use metric capable of forecasting both stability and observability characteristics of a system. The results are illustrated using a sample 3-bus system.