Performance of Symmetrical and Asymmetrical Multilevel Inverters

Distributed Energy Resources (DER) are systems that produce electrical power at the site where the power is needed. If only electrical power is used then the technology is called Distributed Generation (DG). The objective of this paper is to study a novel more than five level multistring inverter topology for DERs based DC/AC conversion system. The distributed energy resource based single-phase inverter is usually adopted in the microgrid system. In order to reduce the conversion losses, the key is to saving costs and size by removing any kind of transformer as well as reducing the power switches. In this study, a high step-up converter is introduced as a front-end stage to improve the conversion efficiency of conventional boost converters and to stabilize the output DC voltage of various DERs such as photovoltaic for use with the simplified multilevel inverter. In addition, two active switches are operated under line frequency. In this project a novel asymmetrical configuration is proposed. The proposed asymmetrical configuration uses less number of switches to get more levels. It will reduce the cost, reduce the number of sources, complexity, losses and improves reliability. The proposed converter is simulated by Matlab/Simulink software and simulation results are presented.