A New Dual-input Buck-boost Inverter with Input Power Balance

Photovoltaic inverters (PV) undertake the critical task of converting the DC power output from PV cells into the AC power required by the grid. In this paper, a dual-input Buck-boost inverter (DIBBI) is innovatively proposed, which combines the Buck-boost circuit module and coupled inductor technology, and has the advantages of fewer switching devices, wider input voltage range, and leakage current suppression. Compared with the traditional dual-input inverter, the newly proposed inverter can effectively cope with the challenge of DC voltage imbalance between PV cells by introducing a coupled inductor, which improves energy utilization of photovoltaic cells. The adoption of dead-beat control (DBC) provides the inverter with extremely dynamic response performance and low current harmonic distortion. Simulation tests verify that the inverter can maintain good grid-connected power quality under balanced and unbalanced input energy conditions.