Mitigating the Effects of Nonlinear Systematic Errors Within PMU Measurement Infrastructure in Three-Phase Power Systems

Abstract

Introduction of Phasor Measurement Units (PMUs) into power grids facilitated several new monitoring and control applications due to the synchronized voltage and current phasor measurements they provide at high sampling rates. However, like any other measurement device they are vulnerable to noise and other errors which may be introduced by the chain of devices such as front-end instrument transformers as well as the various inaccuracies in the overall communication chain. If these errors are systematic, then phasor measurement infrastructure needs to be calibrated to avoid biased estimates of state and network parameters. This paper presents a remote calibration approach to accomplish this within the state estimation algorithm. The proposed approach enables calibrating a diverse range of linear and nonlinear systematic errors in PMU measurements. The method is tested on three-phase 118-bus test system considering examples of quadratic and linear systematic errors. The results prove that the proposed method could be of use in calibrating various types of systematic errors along the PMU measurement chain such as errors in instrument transformers level and/or PMU device itself.