Hybrid State Estimation Model Based on PMU and SCADA measurements

In this paper a short description of a conventional non-linear state estimator based on the measured state variables and data mainly received from SCADA system is given. For comparison, a description of a linear state estimator based exclusively on PMU measurements is given. Then, a new method of a hybrid non-linear state estimation with PMU and SCADA measurements will be proposed where the voltage and current phasors are used for the calculation of real time transmission line parameters (impedance and admittance). 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.