Two switched-inductor quasi-Z-source inverters

Abstract

In this study, two topologies are presented for switched-inductor quasi-Z-source inverters, namely a ripple input current switched-inductor quasi-Z-source inverter (rSL-qZSI) and a continuous input current switched-inductor quasi-Z-source inverter (cSL-qZSI). The proposed inverters possess high boost voltage inversion ability and a lower voltage stress across the active switching devices. Compared with a conventional switched-inductor ZSI, the proposed SL-qZSIs for the same input and output voltage provide a continuous input current and a reduced voltage stress on the capacitors. Moreover, the proposed inverters can overcome the startup inrush current problem but a conventional SL-qZSI cannot overcome this. This study presents the operating principles and analysis, and compares them with the conventional ZSIs. In order, to verify the performance of the proposed converters, a 60 W scaled-down laboratory prototype was constructed and, to test both the configurations it employed a 36 Vdc input and an ac output line-to-line voltage of 83 Vrms. The peak-to-peak input current ripple of the rSL-qZSI and cSL-ZSI is 126.3 and 59.8%, respectively. The experiment results verified that the proposed inverters have high step-up inversion ability, lower voltage stress on the capacitors and lower input current ripple.