High Step-Up Soft-Switching DC-DC Converter Integrated With Y-Source Network

High step-up dc-dc converter is generally used in microgrid, uninterruptible power supply, hybrid electric vehicle, and other applications. For attaining high boosting and high efficiency, a high step-up soft-switching circuit topology with an integrated Y-source network is presented. Its front end is a boost structure with the strengths of continuous and low ripple input current. The active clamp circuit may store the energy of leakage inductance in the output capacitor and then output with reuse. In addition, the switches achieve zero-voltage conduction, thereby decreasing its switching loss. At the same time, the coupling inductor achieves zero dc bias, which reduces the core size and core loss. The converter may attain high step-up by selecting the proper turns ratio of the coupling inductor at a reasonable duty cycle. This article elucidates the working mode of the converter in depth, builds the small-signal model, and studies the stability of the converter. Finally, an experimental prototype of 200-W, 28-380 V, and 100 kHz is built, and the feasibility of the presented converter is demonstrated in both dynamic and static aspects of the experiment.