Optimal PMU placement for improving hybrid state estimator accuracy

Abstract

With the deployment of Synchronized Measurement Technology (SMT), many applications of the existing Supervisory Control and Data Acquisition (SCADA) system have been significantly improved. SMT may be used in many SCADA functions; one of its fundamental applications is in state estimation. The Phasor Measurement Unit (PMU) is the main component of the SMT, providing synchronized phasor measurements from the power system. It is therefore important to determine the optimal PMU locations for improving certain aspects related to state estimation. In this paper, the optimal PMU placement for improving state estimation accuracy is examined. The state estimator incorporates both conventional and synchronized measurements as the full deployment of PMUs in the power systems is neither affordable by electric utilities nowadays, nor practical. The concept of the hybrid state estimator as well as the proposed methodology for determining optimal PMU placements for improving its associated accuracy is presented in this paper. The hybrid state estimator is applied to the IEEE 14, 30, and 57 bus systems. The proposed PMU placement methodology is utilized to determine the optimal PMU placement in these systems. The accuracy of the conventional and hybrid state estimator when applied to IEEE 14, 30, and 57 bus system is also compared.