Analysis of massive measurement loss in large-scale power system state estimation

In the deregulated electric energy market, large-scale network models are necessary to guarantee the reliability of the interconnected power system. These large-scale operating models normally encompass several Control Areas (CA). The State Estimator receives near real time data from these Control Areas by means of dedicated communication links. The loss of one of the links will deprive the State Estimator of a large number of measurements. This paper presents and analyzes the results of State Estimator simulations under the total loss of Control Area measurements in a large regional model. The model selected for simulation is a 2729 bus system. The results obtained indicate that in systems heavily deficient in measurements, the inclusion of only the critical pseudomeasurements that make the system topologically observable results in large estimated angle errors at most of the buses without either a measurement or pseudomeasurement. The results also reveal that the inclusion of injection pseudomeasurements in all the buses of the lost Control Area provides a stable solution and acceptable results.