Typical Transformer-Based Z-Source/Quasi-Z-Source Inverters

This chapter discusses the typical trans and LCCT Z-source/quasi-Z-source inverters (ZSIs/qZSIs). Their configurations, working operations, voltage and current principles, and simulation results are presented, providing a demonstration of the investigation of other extended transformer-based ZSIs/qZSIs. The two DC current blocking capacitors connected in series with the transformer also prevent the transformer core from saturating. The only difference is the charging/discharging of magnetizing inductance in the trans-Z-source inverter, rather than discrete inductances found in the conventional Z-source inverter. They showed improved performance compared to the basic ZSI/qZSI in terms of reduced element counts, compact passive components, and high voltage boosting ability. The unique topology of the LCCT passive input circuit also helped to prevent the transformer core from saturating. Also, by using high switching frequency power devices, such as silicon carbide (SiC) transistors and SiC diodes, high power density is expected for those transformer-based derivations of ZSI/qZSI.