A High Step-up DC-DC Converter with Multiplier Voltage Cells

The non-isolated high voltage gain dc-dc converter becomes the focus of research in the sustainable energy converters. This paper proposes a high step-up dc-dc converter with switched-capacitor and 3-winding coupled inductor. It consists of voltage multiplier cell, coupled inductor, and switched-capacitor. Compared with existing high step-up dc-dc converters, the proposed converter incorporates a switched-capacitor at the output side of the converter, which has a lower impulse current and power loss due to the current limiting effect of magnetic element. Therefore, it makes full use of the boosting capability of the switched-capacitor and avoids its drawbacks. The converter achieves high voltage gain by cascaded boost method, which is composed of 3-winding coupled-inductor based boost cells. It reduces voltage stresses on the components in each cell, achieves high voltage gain by utilizing devices with low on-state resistance and low voltage rating that improves the efficiency. An inherent passive clamp circuit alleviates voltage spike of switch as well as recycles the leakage energy. The converter provides high voltage gain, high efficiency and high power density. The operation modes, steady-state analysis, stresses of the components, comparison with other candidates, and design guideline are analyzed and presented. The validation of the proposed converter is verified by a 200 W prototype constructed in the laboratory.