Abstract: The DC-DC converter converts the low dc input voltage to high voltage without using step up transformer. The Cockcroft voltage multiplier uses the diode and capacacitor is to increase the potential at the output of the converter. The proposed converter is connect to the three phase inverter and feed intothe AC application. The pulse width modulation is used to control and regulate the voltage and current of the inverter. The voltage and current of three phase inverter simulation are verified using the MATLAB Simulink Software.