Incorporating generator exciter dynamics in an observability formulation for nonlinear power systems

This paper extends the proposed observability formulation for nonlinear power systems modeled as a set of Differential Algebraic equations by including additional generator dynamics, and focusing on the impact these additional dynamics have on the overall system observability formulation. In particular, the generator exciter dynamics are included in the power system model (using a network-preserving model of the system), and the observability formulation is determined for this enhanced power system model. The resulting observability Jacobian is compared to the case where the system generators are modeled using only the swing equation, and an example is presented to illustrate the steps needed to construct the observability Jacobian, and evaluate regions in the system state-space where the observability Jacobian is singular, and the system is therefore no longer observable.