Enhanced PMU-Based Line Parameters Estimation and Compensation of Systematic Measurement Errors in Power Grids Considering Multiple Operating Conditions

Several monitoring, protection, and control applications designed for modern power grids are based on detailed grid models and thus require accurate knowledge of line parameters. A synchronized monitoring infrastructure based on phasor measurement units (PMUs) may be of great support to the task of line parameters estimation, but the accuracy of the estimated parameters may be largely affected by the uncertainty of all the elements of the PMU-based measurement chain. Thus, an accurate parameters estimation must appropriately consider the metrological behavior of all these elements, in particular that of instrument transformers (ITs). To address this challenge, this article proposes an enhanced multibranch method for accurate estimation of the line parameters and the systematic measurement errors introduced by the ITs when measurements for multiple operating conditions are considered. Indeed, multiple operating conditions are dealt with properly due to an in-depth analysis of the problem modeling within the framework of Tikhonov regularization. The validity of the proposed approach is confirmed by the results obtained on the IEEE 14-bus test system.