A Two-Step Hybrid Power System State Estimator

In this paper a Two-Step Hybrid State Estimator based on classical SCADA and new Phasor Measurement Units inputs is presented. The 1st step is a linear state estimator that utilizes only synchrophasors. The 2nd step is an iterative state estimator that combines conventional measurements with pseudo-measurements obtained from the 1st step. The developed hybrid model takes advantage of the high sampling frequency of the synchrophasors by running the 1st step state estimator several times between two consecutive runs of the 2nd step state estimator. The methodology was tested on the IEEE 14 and 57 buses test systems and the real full Croatian transmission power system model. It was also compared with other hybrid models. The proposed formulation of the hybrid state estimator is comparable with other hybrid models in view of accuracy and convergence, and it offers enhanced filtering of measurement errors.