Improved Switched-Capacitor Switched-Inductor Z-source Inverter for Increasing Boost Factor and Decreasing Voltage Capacitors Stress

In this paper, the concept of one switched-inductor Z-source inverter is extended to improved switched-capacitor inductor ZSI. In the proposed inverter, capacitors are used instead of the side diodes of the one switched inductor Z-source inverter. The proposed inverter improved voltage gain and boost factor compared to the switched-inductor Z-source inverter and the switched-inductor quasi Z-source inverter. The improved switched-inductor-capacitor Z-source inverter reduces the stress to capacitor voltage. The proposed inverter in this paper can be extended up to the n cascade, thus achieving a higher boost factor of a low duty cycle. The performance of the proposed structure at different operating modes is investigated, and the voltage equations are calculated. The analysis, derivation of the stress of switches voltage, the stress of capacitors voltage, the stress of diode voltage, the stress of inductor current, the gain of voltage, and the boost factor of the proposed inverters are carried out are compared with the similar inverters. To confirm the performance of the proposed converter, a laboratory sample of converters is made, in which, with V-dc = 60 output for the improved switched-capacitor-inductor ZSI of converter, the DC-link (Vi) voltage is 200 with boost factor 1.67, which confirms the relationships obtained from the proposed converters.