Effect of DC-DC Converters on Direct Ethanol Fuel Cells Output

The paper presents an analysis of Direct Ethanol Fuel Cell (DEFC-mesh, and DEFC-foam) systems interfaced to DC-DC converters. The output voltage characteristics of six systems are compared. Experimental results show that DEFC systems present variable, nonlinear impedances as a function of frequency. It is shown, through experimental results, that DEFC systems do not exhibit predictable output as function of duty cycle alone. Consequently, output voltage control through pulse width modulation (PWM) techniques cannot be employed for DEFC systems.. The motivation for this analysis is a preliminary investigation into the use of DEFC´s as a power source for a prototype Martian Uninhabited Aerial Vehicle (UAV).