A new efficient technique for disturbing current extraction to improve the grid current quality in a three-phase grid connected PV system supplying a non-linear load

Abstract

This paper is focused on the improvement of the grid current at the point of common coupling of a three-phase grid connected photovoltaic system supplying a non-linear load. This improvement is achieved by using the PV inverter as a shunt active power filter in addition to its main function of power injection in the grid. The shunt active power filtering is performed to compensate the disturbing grid current introduced by the non-linear load, composed by the set of the harmonic and reactive currents. To do that, this paper proposes a new technique able to extract effectively the correct disturbing load current taken as the reference compensating current in the current control loop of the PV inverter. The effectiveness of the proposed technique in improving the grid current quality is demonstrated through the good obtained simulation results.