A nonlinear observability formulation for power systems incorporating generator dynamics

Traditionally, a nonlinear algebraic model of the power system is used to determine the system observability. In particular, the sensitivity of the system measurements (real and reactive power for example) to the change in the system states (bus voltages and angles) is used as a measure of observability, derived from the power system state-estimation problem. It ignores, however, the non-linear dynamics of the system related to generator performance, non-linear components, etc. The proposed observability formulation accounts for these non-linearities and provides a more comprehensive observability determination. The formulation is derived from a DAE model of the power system, and incorporates the dynamics of the generators present in the system.