Abstract
This paper presents the utilization of an Ultra-capacitor as an auxiliary power source in a hybrid power system, composed of a Polymer Electrolyte Membrane Fuel Cell (PEMFC) as a main energy source. The PEMFC source may not be sufficient to satisfy the power required, especially, the peak demand periods. So, we use an Ultra-Capacitor (UCap) because it offers a very fast power response and a high specific power. In addition, the UCap can round off the slowdown of the main source output power to produce the effectiveness and performance characteristics needed to a variable load. A regulation for the PEMFC and the UCap was given. Furthermore, a Power Management Unit (PMU) is proposed in order to reach the good functioning of the system. The analysis and the evaluation of the PMU is performed through simulation results to verify the reliability and the effectiveness of the proposed system using Matlab/Simulink environment.