Multi-Snapshot PMU-based State Estimation Considering Line Parameters Uncertainty and Systematic Errors

Phasor measurement units (PMUs) are the backbone of modern wide-area transmission systems monitoring, providing synchronized measurement data to state estimation algorithms. In this respect, two important and challenging aspects are often overlooked. On the one hand, there is typically rough knowledge about the values of line parameters. On the other hand, phasor estimates returned by PMUs are affected by uncertainty, and systematic errors introduced by the instrument transformers (ITs) usually represent the largest contribution. The present paper proposes a new, multi-snapshot approach to state estimation that leverages data from different time instants to reduce the impact of uncertainty affecting line parameters and phasor measurements. The better quality of the estimates with respect to conventional methods is enabled by a simple yet effective statistical representation of the errors.