A Novel Converter Topology for High Step-Down Conversion Ratio DC-DC Converter with Low Voltage Switch Stress

In this paper, a novel converter topology for interleaved high step-down conversion ratio dc–dc converter with low switch voltage stress is proposed. In the proposed converter, two input capacitors are series-charged by the input voltage source and parallel discharged by a new twophase interleaved buck converter topology without adopting an extreme short duty cycle for delivering a much higher step-down conversion ratio. Based on the capacitive voltage division, the main objectives of the new voltage-divider circuit in the converter are for both storing energy in the blocking capacitors for increasing the step-down conversion ratio and reducing voltage stresses of active switches. As a result, the proposed converter topology procures the low switch voltage stress ascribe. This will allow one to choose lower voltage rating MOSFETs to reduce both switching and conduction losses. The overall efficiency is subsequently enriched. The converter features automatic uniform current sharing characteristic of the interleaved phases without adding extra circuitry or complex control methods due to the charge balance of the blocking capacitor. The operation principles and relevant evaluation of the propositioned converter are offered in this project. Finally, a 400-V input voltage, 25-V output voltage, and 400-W output power prototype circuit and simulated using MATLAB to verify the performance.