Observability Analysis Using Extended Incidence Matrix

Power system state estimator uses the set of available measurements such as voltage and power in order to estimate the system state. Given a set of measurements and their locations, the network observability analysis will determine if a unique estimation can be found for the system state. This paper proposes Extended Incidence Matrix (EIM) for the observability analysis which includes observability test, identification of observable islands and placement of Phasor Measurement Unit (PMU) device for network observability. In order to check the adequacy of the existing measurement configuration, the observability analysis was carried out using off-line simulation during the initial phase of a state estimator installation. The effectiveness of the proposed method is verified using IEEE 14 and 30 bus test case system.