A Novel High Step-Up Quasi-Z-source DC-DC Converter with Coupled-inductor and Switched-Capacitor Techniques

High voltage gain converters with voltage boost capacity can be used for many different occasions, such as renewable energy generation systems, fuel cell systems, uninterruptible power supplies(UPS) systems, photovoltaic(PV) hydrogen production systems. In this paper, A novel high voltage gain dc-dc boost converter based on quasi-Z-source circuit is proposed. By utilizing the coupled-inductor and switched-capacitor techniques, the boost capacity is increased with switch voltage stress unchanged and duty ratio unlimited. Compared with other existing high step-up structures, the proposed structure can use the same number of devices to achieve higher voltage gain. Detailed analysis including operating mode, steady-state analysis and power loss analysis are also shown in this manuscript. Finally, an 200W experimental protype were built to examine the theoretical analysis.