Single-Phase Quasi-Z-source based Isolated DC/AC converter

Abstract

This paper presents a new Single-Phase Quasi-Z source based Isolated DC/AC converter topology preferably suitable for residential/distributed generation applications. Quasi-Z source inverter provides additional benefits of reduced component ratings, improved input current profile and enhanced reliability in comparison with other topologies of Z source network. A new modulation technique is developed to minimize the switching loss and to increase the overall efficiency of Quasi Z source inverter. An Indirect voltage control scheme is employed for control of DC link voltage. A Multi winding High frequency transformer is used for galvanic electrical isolation, improved power density and better gain. A seven level inverter with reduced switches is used for realizing DC/AC power conversion at the secondary side of the transformer. The proposed model is developed in Matlab/Simulink environment and the simulation results are presented for changes in load and for step changes in input voltage.