Two different non-shoot-through operating modes for generating changeable general boost factor in switched Z-source inverters with modified modulation technique

Abstract

In this study, a new switching pattern for switched Z-source inverters (ZSIs) is proposed. By this technique, the switched ZSIs can generate general boost factor with different functions. The proposed modulation technique is a general technique and can be applied for all types of switched boost inverters, switched ZSIs and active ZSIs. The mentioned inverters do not use additional passive elements in comparison with the conventional ZSI. Moreover, variable boost factor with ability of changing both switching factor and shoot-through duty cycle makes these inverters more valuable than transformer-based ZSI. Applying the proposed technique leads to make different non-shoot-through (nST) operating modes which are named adjacent-nST and non-adjacent-nST operating modes. The extraction of equations and steady-state analyses for a type of switched ZSIs in different operating modes are presented. In addition, the design considerations and calculation of critical inductance in the new switching pattern are given. The logical diagram of the switching pattern is introduced and comparison between different types of switched ZSIs with the proposed switching pattern from different aspects is done. Finally, the simulation and experimental results are given to show the good agreement between the theoretical and measured results.