An energy stored quasi-Z source cascaded multilevel inverter based photovoltaic power generation system

This paper proposes an energy stored quasi-Z source (qZS) cascaded multilevel inverter (ES-qZS-CMI) based photovoltaic (PV) power generation system. The system combines advantages of both the qZS inverter and the cascaded multilevel inverter; moreover, the system uses a battery in each module to balance the stochastic fluctuations of PV power injected to the grid. This paper also proposes an effective control scheme for the ES-qZS-CMI based PV system, using which the system can achieve the distributed maximum power point track (MPPT) for each PV panel, balance the power between different modules, and provide the desired power for the grid. Simulation and experimental results verify the proposed system and the control scheme.