A Single-Inductor Multi-Input Multilevel High Step-Up DC–DC Converter Based on Switched-Diode-Capacitor Cells for PV Applications

Abstract

This article presents a single-inductor multi-input multilevel high gain dc–dc converter, which is suitable for exploiting arbitrary number of PV arrays to provide fixed voltage levels for multilevel inverters. The converter is capable of transferring power from each input to the output, at the same time. Additionally, the proposed structure provides outputs with same voltage levels that makes it appropriate for connecting to multilevel inverters. Due to the deployment of diode-capacitor cells, which have been extended from both nodes of the central capacitor, the output voltage ripple has been decreased, which leads to the employment of capacitors with smaller size. Also, the number of inputs and outputs can be chosen arbitrarily. In addition, because of the utilizing only one inductor, the cost, and total size of the converter has been reduced. The control approach of the converter is pulsewidth modulation and all switches can be turned <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> or <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> , simultaneously. The theoretical analysis and gain calculations of the converter has been investigated in this article. In order to design the converter, the voltage ripple across each capacitor has been calculated. Furthermore, a comprehensive comparison has been performed between the proposed converter and counterparts. Finally, a dual-input three-level prototype of the proposed converter with 300 W output power has been implemented to confirm the validity of the converter's performance.