Abstract: In the field of Renewable energy resources (RES) are connected in distribution systems by using power electronic converters. Inside this paper presents a detailed control idea of reach maximum benefit from grid-interfacing inverters put in 3-phase 4-wire distribution systems. The inverter is controlled to perform an electronic device by incorporating active power ?lter functionality. The inverter can thus be utilized as: 1) Inject power generated from RES to the grid, and 2) unbalance current, load current harmonics, load reactive power demand and load neutral current compensate by shunt active power filter. Those all functions could also be accomplished either individually or simultaneously. With such a control, the mix of grid-interfacing inverter and the 3-phase 4-wire linear/non-linear unbalanced load at PCC appears as balanced linear load to the grid. With using of MATLAB/Simulink software this new concept is demonstrated.

Keywords: Active Power Filter (APF), Distributed Generation (DG), Power Quality (PQ), Point of Common Coupling (PCC).