A novel grid voltage feed forward control strategy for three-phase grid-connected VSI with LCCL filter

In this paper, a novel grid voltage feed forward control strategy under d-q rotating frame is proposed based on three-phase grid-connected voltage source inverter (VSI) with LCCL filter to suppress the grid current harmonics caused by the grid voltage distortion. Although the control strategy of grid-connected inverter with LCCL filter has many advantages, this control strategy fails to control grid current directly making the current sensitive to grid voltage distortion. A feed forward component of grid voltage is derived to completely eliminate the grid voltage impact on grid current. To make this control strategy applicable, an equivalent scheme in which grid voltage feed forward components are separately inserted into current reference and modulation is proposed. The results of both simulation and experiment of 100kW prototype verify the effectiveness of the proposed scheme.