An Improved Hybrid State Estimator with Inclusion of Transmission Line Models

This paper presents a hybrid state estimator method which utilizes both PMU measurements and the estimated voltage phasors from SCADA based state estimator. In general, incorporation of PMU measurements into the conventional state estimator is done to enhance its accuracy. This hybrid state estimator method requires a transmission line model for pseudo measurement calculations. The accuracy of state estimator also depends on the choice of line model for these calculations. In this paper, an improved hybrid state estimator method, which utilizes long transmission line model or distributed parameters model for pseudo measurement calculations, has been proposed. The proposed method is tested with standard IEEE 14-bus and 118-bus test systems. The obtained results from these test systems are very promising. These results have been compared with existing hybrid state estimator method which utilizes medium transmission line model for pseudo measurement calculations. The paper presents the comparison of voltage magnitude and angle errors between the proposed and existing methods.