A Solar Photovoltaic System by Using Buck Boost Integrated Z-Source Quasi Seven Level Cascaded H-Bridge Inverter for Grid Connection

Abstract

This paper brings up a grid-connected photovoltaic (PV) interface from the combined use of quasi-Z source inverter (qZSI) and cascaded H-bridge (CHB) inverter. Controlling and modeling of a Z-Source quasi CHB Seven level Inverter has been done. In one stage dc to ac conversion together with the buck/boost output is given by Quasi ZSI. PV applications requires best topology like this because of its numerous advantages such as reduced THD, high reliability and gain. Network for impedance has been drafted in this work for a seven level Z-source CHB Quasi inverter. To control switches of inverter shoot- through control along with Phase Shifted Inverted Sine carrier pulse width modulation is executed. In two stages power control scheme in closed loop condition is executed here. Controlling of each string voltage at the input side of photovoltaic is done by varying the inverter shoot-through type states with the help of individualistic Maximum Power Point Tracking control method. Each bridge DC link voltage was equalized with the help of DC link voltage control scheme. Controlling of grid transferred power is achieved from both of these controlling actions. A 2 Kilowatt photovoltaic inverter were designed simulated and executed with MATLAB simulation tool and also verified the open loop control.