A Hybrid State Estimator using Current based Estimator and PMU Measurements

Abstract

The increasing use of synchronized phasor measurements in modern power systems has made it necessary to consider its effects on the state estimation algorithm. Accuracy of the measurements used has a great impact on the output of state estimators. Thus including the highly accurate phasor measurements into the existing state estimators can be highly beneficial. With the advent of synchrophasors, modifications in the existing state estimators have to be considered as most of the existing estimators rely primarily on conventional measurements from SCADA system. The conventional state estimators are traditional Power based estimators. The faster convergence of current based estimators as against the traditional power based estimators has already been proved in the literature. This necessitates the need for modifying current based estimators to incorporate PMU measurements. This paper investigates a technique to incorporate the PMU measurements into a current based state estimator. The model used for incorporating the PMU measurements is a linear model and hence can be solved non-iteratively. The result is being discussed for standard IEEE 14 bus test case. The results indicate that the output obtained from the estimator using both PMU data and conventional data is much more efficient than the existing current based state estimator.