A Transformerless High Step-Up DC-DC Converter Based on Voltage Multiplier

this project deals with a high step-up dc-dc converter based on the Cockcroft-Walton (CW) voltage multiplier without a high frequency transformer. Providing continuous input current with low ripple, high voltage ratio, and low voltage stress on the switches, diodes, and capacitors, this converter is quite suitable for applying to low-input-level dc generation systems. Moreover, based on the n- stage CW voltage multiplier, this converter can provide a suitable dc source for an (n + 1) -level multilevel inverter. In this paper, the control strategy employs two independent frequencies, one of which operates at high frequency to minimize the size of the inductor while the other one operates at relatively low frequency according to the desired output voltage ripple. Simulation results demonstrates the validity of the new converter. The simulation of the converter is done with MATLAB /SIMULINK software.