A Critical Analysis of Non-ideal Quasi Z Source Inverter Considering with Parasitic Resistances

Abstract

This paper describes the perfect small signal mathematical modeling of a non-ideal quasi-Z-source inverter (q-ZSI) by considering the parasitic resistances of capacitors and inductors. In this work, the detailed transfer function model of the system is derived mathematically by using state-space averaging method under continuous conduction mode (CCM). The deduced transfer function model exhibits the non-minimum phase of a system in the capacitor voltage-to-control transfer function due to the presence of Right-Half-Plane (RHP) zeros. The RHP zeros could impose a limitation on the controller design. Therefore, the effect of parasitic resistances of passive elements on system dynamics is analyzed with the frequency response plots such as Bode plot, Root locus and Pole-Zero maps. This analysis helps to frame the guidelines for selecting the pertinent values of passive components and their parasitic resistances. The system stability and dynamic response of the presented small signal model are compared with circuit model and validated in Mat lab/Simulink environment