Power System State Estimation using Non-Iterative Weighted Least Square method based on Wide Area Measurements with maximum redundancy

The power system state estimation (PSSE) accuracy is crucial for monitoring and surveillance in an energy management system (EMS). Wide-area measurement systems (WAMS) are a pivotal technology to enhance the accuracy of PSSE. Further, with the advent of phasor measurement units (PMUs), state estimation got revolutionized by its performance. To attain better estimation accuracy, the main considerations for a power system are; observability and redundancy. In order to achieve full observability with maximum redundancy, the problem of optimal PMU placement (OPP) in power systems is investigated. This paper proposes a Modified Integer Linear Programming (M-ILP) technique to achieve full observability with minimal PMU placement and maximum redundancy. Furthermore, A Non-iterative Weighted Least Square (NI-WLS) approach has been developed to improve the accuracy of power system state estimation by leveraging hybrid measurements consisting of traditional SCADA data and phasor measurements. The efficacy and precision of the proposed algorithms have been demonstrated through extensive simulations on a wide range of test systems, including standard IEEE-14, 30, 57, 118 systems and real-time Indian Northern Region Power Grid-246 (NRPG-246) bus system. Moreover, the proposed methods show significant improvement in the accuracy and stability of the state estimate solution.

Automated summary

In this study, the accuracy of power system state estimation is addressed. A modified integer linear programming technique is proposed to achieve full observability with maximum redundancy. Additionally, a non-iterative weighted least square approach is developed to improve the accuracy of state estimation. Extensive simulations on various test systems demonstrate the effectiveness and precision of these methods.