Single-phase cascaded semi-Z-source inverter for photovoltaic applications

In this paper, a single phase cascaded semi-Z-source inverter is proposed for photovoltaic (PV) applications. The proposed semi-Z-source inverter utilizes a nonlinear Sinusoidal Pulse Width Modulation (SPWM) to produce sinusoidal voltage at the output as microinverter. The proposed system is able to produce an AC voltage at its output terminals by utilizing only four switches for each PV cell. Moreover, the proposed system overcomes the shading problem of PV systems as the maximum power point tracking can be independently achieved. One of the main advantages of the proposed topology is its modularity, which leads directly to increase the installed power. In addition, the proposed topology reduces the Total Harmonic Distortion (THD) and DC current components at the output during DC-AC conversion.