Derivation of instantaneous current references for three phase PV inverter connected to grid with active and reactive power flow control

In this paper, inverter reference current generation for a three phase grid connected PV inverter under generalized grid voltage conditions is proposed. The proposed method facilitates high bandwidth grid active and reactive power flow control along with minimum DC link ripples with grid current THD control facility by finding suitable current reference directly in the a-b-c frame. The proposed method is much faster than the conventional methods because of the absence of phase lock loop (PLL) and Park´s transformation requirements. The proposed method is also independent of grid voltage fundamental frequency and capable of rejecting the grid voltage harmonics. These advantages make it more suitable for micro-grid applications. The proposed method is validated with rigorous experiments and test results presented depict the efficacy of the proposed system.