Performance Assessment of Synchronized Phasor Measurement-Based Parameter Estimation for Distribution Networks

Refined Modeling and Compensation of Current Transformers Behavior for Line Parameters Estimation Based on Synchronized Measurements

“…As pointed out during the introduction, the first step that can help improving estimation algorithms, like for example [17], is investigating the metrological behavior of CTs that, as a result of the combination between core nonlinearity and wide measurement range, is not well represented by constant ratio error η and phase displacement (or phase error) ψ [16]. Both experience and mathematical considerations on the CT model confirm that its behavior at the fundamental is barely affected by the presence of harmonics [21], [22], [26].…”

“…The method is based on PMU measurements at both ends of each line and exploits prior information about IT uncertainty. In [17], the method has been extended to include also shunt parameters among the estimates, and it has been tested in presence of distributed generation (DG). However, the method needs to be validated under more realistic conditions.…”

“…Moreover, these data have been also exploited to define simplified parametric models aimed at capturing the basic features of their behavior, in particular the relationship between error values and current magnitude. Finally, the approach [17] has been modified to include the parameters of these elementary CT models in the vector of the estimates. The improved algorithm can thus embed most part of the systematic effects due to CTs: this enables a better reconstruction of line currents and a more accurate measurement of the line parameters, as highlighted by the obtained results.…”