Observability analysis of power systems in the presence of hybrid measurements

Phasor measurement units (PMUs) are increasingly being used in modern power systems due to their high reporting rate and accuracy. The majority of the measurement devices in the existing power systems, however, are conventional asynchronous measurements. State-of-the-art state estimation algorithms are therefore required to include the hybrid set of measurements. Observability of the system with the given set of measurements is a pre-requisite of any state estimator. This paper proposes a numerical algorithm for observability analysis of power systems having hybrid measurements. The proposed method is demonstrated with the help of a number of test systems.