Structure analysis and sliding mode control of new dual quasi-Z-source inverter in microgrid

Abstract

In this paper, a new topology of the 5-level neutral-point-clamped dual quasi-Z-source inverter is proposed, which can effectively inhibit the start current of the inductor of Z-source network and improve the boost capability of the DC side of inverter in contrast to traditional 5-level neutral-point-clamped dual Z-source inverter. Furthermore, the mathematical model of the quasi-Z-source network and the transient analysis are deduced by using the state space method and small signal model respectively. Meanwhile, a method based on sliding mode control for improving the new topology transient response is also presented. The method does not require linearization, and the corresponding control law is obtained by selecting appropriate state variables. Finally, the simulation and experiments verify the superiority and effectiveness of sliding mode control.