An ultra high-gain switched-capacitor-inductor DC-DC converter with reduced voltage stress.
This paper introduces a new non-isolated step-up DC-DC converter based on a switched-capacitor-inductor (SCI) network that achieves high voltage gain at modest duty cycles. The proposed topology is distinguished by several simultaneous merits: low voltage stress on all power switches and diodes, a common ground between the input and output ports, continuous input current, and a superior gain-per-component ratio with respect to inductors, capacitors, and diodes. Thanks to the reduced semiconductor voltage stress, switching losses are mitigated, and the converter can employ lower-voltage active devices, which are inherently more efficient and cost-effective. The converter also features an inherently modular multi-stage structure, allowing it to scale to higher voltage and power levels without proportionally increasing semiconductor stress, which is an advantage over conventional quadratic or coupled-inductor-based high-gain designs. The paper presents a comprehensive steady-state analysis in both continuous (CCM) and discontinuous (DCM) conduction modes, derives the voltage gain and component stresses, and provides a detailed comparative evaluation against state-of-the-art step-up topologies in terms of voltage gain, semiconductor stress, component count, and efficiency. A 400 W laboratory prototype with 48 V input and 400 V output, operating at 25 kHz, was built and tested. Experimental results confirm the theoretical analysis and demonstrate a measured efficiency of 94.9%.