POWER ELECTRONICS ABSTRACT 2016-2017 ANALYSIS AND DESIGN OF CURRENT-FED HIGH STEP UP PWM CONTROLLED QUASI-RESONANT DC-DC CONVERTER FOR FUEL CELL APPLICATIONS ABSTRACT: A Soft-Switching DC-DC Converter with low voltage and current stresses on switches and high voltage gain is proposed in this paper. The voltage and current stresses of switches are considerably reduced. As a result a reduction of switching losses in turn ON and OFF states of switching is obtained. Also, using soft-switching method results lower losses. In the result of ZCS in output diodes, reverse recovery problem of diodes is alleviated. Because of total reduction of losses, efficiency is improved. The proposed converter is a quasi- resonant converter controlled by pulse width modulation (PWM) method.