A Novel High Step-Up Nonisolated Quasi-Z-Source DC–DC Converter With Active Switched Inductor and Switched Capacitor

Abstract

In this article, a novel high step-up nonisolated quasi-Z-source (qZS) dc–dc converter is proposed and analyzed. The converter utilizes both the active switched-inductor and switched-capacitor structures on the basis of the qZS network to improve the overall voltage gain. The proposed converter retains the advantages of the traditional qZS boost converter, such as continuous input current, common ground between the input and output, and low voltage stress on capacitors. Meanwhile, the voltage gain is significantly improved without changing the maximum duty cycle of the traditional qZS boost converter. And the voltage stress of each power switch is greatly reduced. The steady operating principle and the steady characteristics of the proposed converter are discussed in detail. Also, the power loss calculation for nonideal elements is presented. Finally, a 300-V/300-W prototype is built in the laboratory to verify the performance of the proposed topology, and a comprehensive comparison of the proposed converter with other qZS-based converters is provided to demonstrate the advantages of the proposed converter.