Cost-Effective Quadratic Ultra-High Gain DC–DC Converter With High Power Density for DC Microgrid Applications

This paper presents an ultra-high voltage gain, quadratic-based DC-DC structure optimized for cost-effectiveness and high power density, specifically for DC microgrid applications. The proffered design integrates a coupled inductor (CI) with a quadratic step-up structure to accomplish a substantial step-up in voltage. The converter’s voltage gain can be regulated through two key criteria: the duty cycle of the power switches and the turn ratio of a two-winding CI, providing enhanced flexibility in design. Key attributes of the proffered topology encompass its ultra-high voltage gain, reduced voltage stress on the switching components, continuous input current, a common ground among the input and output, high efficiency via soft switching on semiconductor devices, and synchronized switch operation. Comprehensive details are provided on the operational principles, steady-state behavior, design considerations, and efficiency evaluation, accompanied by dynamic modeling and control assessment. To highlight the advantages of this topology, it is compared with other related topologies. The potential of the suggested design is affirmed by testing a 600W experimental system utilizing a switching frequency of 50 kHz, with an input voltage of 20 V and an output voltage of 600 V.