Soft-Switched SEPIC-Based DC–DC Converter With High Voltage Gain for Battery Charging Applications

This paper presents a novel soft-switched SEPIC-based DC-DC converter designed to achieve high voltage gain with improved efficiency and reduced switching losses.The proposed topology integrates a modified SEPIC structure with an auxiliary soft-switching network that enables zero-voltage and zero-current switching conditions for the active power devices.By employing this technique, the converter significantly minimizes switching stress and electromagnetic interference, allowing efficient operation at high switching frequencies.High voltage gain is obtained without resorting to extreme duty cycles, which reduces conduction losses and improves overall system reliability.Additionally, the converter maintains continuous input current, making it well suited for renewable energy sources such as photovoltaic systems and fuel cells.The operating principles and steady-state behavior of the converter are analyzed in detail, and key design equations are derived to guide practical implementation.Simulation results validate the theoretical analysis and demonstrate enhanced voltage gain, reduced power losses, and improved efficiency compared to conventional SEPIC and boost converters.The proposed converter offers a compact, efficient, and reliable solution for high step-up DC-DC conversion applications where soft switching and high performance are critical.