Multilevel cascaded Z source inverter for PV power generation system

Abstract

The paper investigates the use of multilevel cascaded Z source inverter (MC-ZSI) for photovoltaic (PV) power generation system. The control of the proposed system will take into account the multilevel modulation scheme and the independent control of the shoot-through duty ratio of the connected Z source inverters (ZSI). In three phase three cells inverter, there exist nine independent shoot-through duty ratios to control nine ZSI modules. These shoot-through duty ratios will be combined in the conventional phase shift multilevel modulation scheme to form the final gating pulses for the MC-ZSI. For grid connection operation, deadbeat control is used due to its fast response and high accuracy. Simulation results verified the effectiveness and reliability of MC-ZSI. © 2012 IEEE.