Phasor-assisted Hybrid State Estimator

Abstract

This article proposes a simple and effective approach to incorporate phasor measurements in the existing traditional supervisory control and data acquisition measurements based state estimation software. A phasor assisted hybrid non-linear state estimator has been proposed, where both supervisory control, data acquisition, and phasor measurements are integrated together and utilized to enhance the accuracy of the conventional weighted least square state estimator. A sequential phasor-assisted state estimation approach is also presented, where, in the first stage, the conventional weighted least square state estimation is run using supervisory control and data acquisition measurements, and, in the second stage, voltage and current phasor measurements from phasor measurement units are utilized to enhance the output of the conventional weighted least square estimator. The results of both estimators are compared to establish the effectiveness of the proposed method on three test systems, namely, the IEEE 14-bus system, the New England 39-bus system, and the Northern Region Power Grid 246-bus Indian system.