New feed-forward control strategy of single-phase grid-connected inverter. Issue 1 (April 2021) - Cao, Ziheng
Abstract: Traditional proportional feed-forward strategy can well restrain harmonic disturbance from grid background, but in the weak grid, positive feedback channel and grid-connected current inner-loop are coupling with each other by grid impedance, and robustness is substantially decreased. According to the above situation, a kind of new feed-forward control strategy is proposed, and adding more resonant link on positive feedback channel of point of common coupling voltage to change full pass characteristics of positive feedback channel which only make positive feedback channel have feedback effect on the frequency of main grid background harmonics. Inverter can both have great robustness and harmonic suppression ability in weak grid. In the end, the effectiveness and correctness of proposed control strategy is verified by the simulation model of single-phase grid-connected inverter.