A FBD theory based grid frequency independent current reference generation method for a three phase inverter interfacing renewable energy sources to generalized micro-grid

In this paper, inverter reference current generation using position sampled FBD method for a three inverter interfacing the renewable energy source to the generalized micro-grid is proposed. The proposed method facilitates high bandwidth grid active power flow control along with grid current THD control facility by finding suitable current references directly in the a-b-c frame. The proposed method is less computational intensive than the conventional p-q theory based methods because of the absence of phase lock loop (PLL), Park´s transformation requirements and positive and negative sequence grid voltages extraction. The proposed method is also independent of grid voltage fundamental frequency and capable of rejecting the grid voltage harmonics. The proposed method is validated with experimental study and test results presented depict the efficacy of the proposed system.