A High Step-Up Nonisolated DC–DC Converter with Switched-Inductor/Switched-Capacitor

Abstract

In conventional step-up converters, the voltage gain is obtained at a high duty cycle. Due to high current ripple, high voltage stress and low efficiency, the high voltage gain is limited. Various methods can be incorporated to solve this problem. One of the most effective methods to reach high step-up operation is switched capacitor/switched inductor technique. In this paper, two nonisolated DC–DC converters with high gain are proposed. These converters, when compared to existing methods, offer significant advantages such as low current and voltage stresses across active elements, high gain (above 20), high efficiency and simple structure. The ideas are based on the switched-inductor/switched-capacitor. The operating principles of the converters are presented. The second converter originated from the first topology, and it has many improvements, such as high gain, low voltage stress on output diode and switches and no current spike in the output diode. Therefore, the second converter is designed and constructed. The experimental results confirm its successful performance.