Design and simulation of quasi-Z source grid-connected PV inverter with battery storage

The quasi-Z-source inverter (qZSI) which originated from the Z-source inverter (ZSI) topology provides an alternative for the conventional two stages DC-DC/DC-AC PV based inverter system with less component number, simpler topology and overcomes some of the limitations and problem associated with the conventional inverter topology. In the application of grid-connected PV inverter system, power storage becomes a critical requirement as a backup to fulfill the power demand. In this context, the qZSI topology has the advantage of easy connection with the storage element with a very minimal modification. This paper presents the grid-connected PV inverter system based on the qZSI topology with a storage capability. The main elements required for the system; the MPPT, dc-link and current control, and the energy storage are detailed plus the analysis of the circuit operation. The simulation results demonstrate the system able to work accordingly.