A Single-Switch Converter With High Step-Up Gain and Low Diode Voltage Stress Suitable for Green Power-Source Conversion

This paper proposes a single-switch converter with high step-up gain and low diode voltage stress, suitable for green power source conversion. By employing a coupled inductor and switched capacitor, the proposed converters achieve high step-up conversion ratio without adopting extremely high duty ratio or high turns ratio. The voltage spike that occurs on the power switch is alleviated, which allows a low-voltage-rated power switch with low RDS(ON) to be adopted, thus reducing the conduction losses. Because the energy of the leakage inductor is recycled, the efficiency is improved. In addition, all diodes' voltage stresses are lowered and are the same, so the selection of power diodes is convenient. Finally, a 300-W prototype circuit with an input voltage of 24 V and an output voltage of 400 V is implemented to verify the performance and functionality of the presented converter. Moreover, the measured highest efficiency is 95.4%.