Grid-tied single source quasi-Z-source cascaded multilevel inverter for PV applications

A new cascaded multilevel topology is proposed in this study. It is denominated single DC source quasi-Z-source cascaded multilevel inverter (SS qZS-CMI). The SS qZS-CMI performs at maximum power point tracking of the photovoltaic (PV) array with a single inverter module and each of the inverter modules shares an equal amount of the power of the whole system. The SS qZS-CMI has the capacity to equally regulate the peak voltage on each inverter module by means of the dual control loop of the main inverter module and the shoot-trough state of the auxiliary inverter modules, ensuring the symmetry of the cascaded multilevel inverter. Experimental results verify the proposed topology.