Robust power system state estimation by appropriate selection of tolerance for the least measurement rejected algorithm

Abstract

Modern power systems are highly complicated and nonlinear in nature. Accurate estimation of the powersystem states (voltage-magnitude and phase-angle) is required for the secure operation of the power system. Thepresence of bad-data measurements in meters has made this estimation process challenging. An efficient estimatorshould detect and eliminate the effect of bad data during the estimation process. Least measurement rejected (LMR) isa robust estimator that has been found successful in dealing with various categories of bad data. The performance ofLMR depends upon the proper selection of a tolerance for each measurement. This paper presents a novel approach fortolerance value selection to improve the capability of handling different single and multiple bad-data scenarios successfully.The performance of this updated LMR (ULMR) is compared with weighted least squares, weighted least absolute value,and two versions of LMR from the literature. IEEE 30-bus and 118-bus systems are used to demonstrate the robustnessof the proposed estimator under different bad-measurement (single and multiple) scenarios.