An Energy Stored Quasi Z Source inverter for Photovoltaic Application

Abstract: The quasi-Z-source inverter (qZSI) with battery operation can balance the stochastic fluctuations of photovoltaic (PV) power injected to the grid/load. This work proposes a new topology of the energy-stored qZSI to overcome this disadvantage and delivers the continuous power to the grid/load. The operating characteristic of the proposed solution is analyzed in detail and compared to that of the SPWM and TPWM. Two strategies are proposed with the related design principles to control the new energy-stored qZSI when applied to the PV power system. They can control the inverter output power and manage the battery power, simultaneously. The quasi-Z-source inverter (QZSI) is a single stage power converter derived from the Z-source inverter topology, employing an impedance network which couples the source and the inverter to achieve voltage boost and inversion. The voltage boost and inversion, and energy storage are integrated in a single stage inverter. The validity of the proposed PV system is proved by experimental results, showing an efficient method for the energy-stored PV power generation.