Grid Impedance Estimation by Measuring Only the Current Injected to the Grid by a VSI with LCL Filter

ROBERTO FANTINO; CLAUDIO BUSADA; JORGE SOLSONA

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Lugar: New York; Año: 2021 vol. 68 p. 1841 - 1850

0278-0046

A strategy for grid impedance estimation is proposed in this work. The strategy is based on the use of an observer suitable to implement the control and synchronization of a VSI with LCL filter, by measuring only the current that the system injects to the grid. The estimationis done based on a modification of the original structure of the observer, together with the implementation of a grid current injection strategy, that allows the observer to adapt in the presence of grid impedance uncertainty. The proposed strategy provides an accurate estimate of the grid impedance inductive and resistive components, suitable for control purposes. The validity and effectiveness of the proposal are demonstrated by simulation and experimentalresults.