Hybrid State Estimation Model Based on PMU and SCADA Measurements

:In this paper, a new method of hybrid non-linear state estimation with PMU and SCADA measurements will be proposed. PMU measurements, the voltage and current phasors, are used for real time transmission line parameters (impedance and admittance) calculation. Transmission line parameters are input data for the conventional state estimator. Calculated parameters of the transmission lines based on the real time PMU measurements are compared with the measured impedance and admittance. The simulation results were carried out on 400 kV Croatian power system. An index of accuracy is set and used to quantify the impact of PMU measurements on power system state estimation by using proposed hybrid model. Software for the proposed hybrid model was developed and it is compatible with PMUs form different vendors. This research was made possible by implementation of 5 PMUs and restoration of wide area monitoring (WAM) system in Croatian power system. Those PMUs were implemented during the reconnection process - reintegration of the 1st and 2nd UCTE synchronous zone.