A Low Input Current Ripple High Step-Up DC-DC Converter with Reduced Voltage Stress for Renewable Energy Application

This report develops a high step-up topology employing a voltage multiplier cell (VMC) and a coupled inductor for renewable energy usage. The efficiency is improved and the blocking voltage on semiconductors is decreased. The proposed structure achieves a high voltage gain by utilizing a VMC and one coupled inductor. This structure employs only one MOSFET switch, lowering the cost of the converter. Further benefits are the reduced number of components and the low blocking voltage of the switches/diodes. Furthermore, the VMC functions as a clamp circuit, reducing the peak voltage of the switch. Consequently, in the presented converter, a low nominal voltage MOSFET can be operated. The switching modes, steady-state analysis, and comparative study with other comparable converters demonstrate the converter’s performance and superiority. A 200W laboratory scale operating under the 25kHz switching frequency and a voltage conversion of 20V~150V is built to validate the theoretical equations. The proposed converter efficiency at the full load is about 96.3%. Also, the normalized maximum voltage stress on switch and diodes for duty cycle D=0.6 and turn ratio N=2 is about 0.33 and 0.8, respectively.