Research on input current ripple reduction of two-stage single-phase PV grid inverter

Due to the instantaneous input and output power unbalance in two-stage single-phase photovoltaic(PV) grid inverter, its front-end Boost converter tends to draw a current ripple with double grid frequency. In this paper, the low frequency current ripple reduction method is proposed, based on a duty ratio compensation model to control duty ratio of the boost converter without any extra cost. The duty ratio compensation model is built and derived, which is verified in SABER environment. The simulation proves that the duty ratio compensation method can effectively reduce and even eliminate the low frequency input current ripple in two-stage single-phase PV grid inverter.