Application of a digital ANF-based power processor for micro-grids power quality enhancement

The ability of distributed generation sources to enhance the power quality of micro-grids is an important issue for the emerging power grid. This paper proposes a decentralized approach for power quality improvements in smart micro-grids. In this scheme, a modified reduced-order digital adaptive notch filter has been introduced and employed to extract the harmonic content of power system variables such as current or voltage. A universal digital power processor has been developed accordingly to intensify the power quality enhancement capabilities of distributed generation systems. The proposed technique allows for compensation of either particular unwanted frequency components or a wide range in the spectral content of the injected current. Current harmonics of non-linear local loads have been therefore compensated by the distributed generation source and a quality electric power is injected to the grid. Simulation results verify the accuracy and validity of the proposed scheme.