A hybrid system comprising a fuel cell stack and a battery bank was developed, built and tested in this research work. This hybrid system was built to supply both DC and AC outputs. The voltage levels set on electrical interconnection points are achieved with several power conditioning stages controlled by Pulse Width Modulation (PWM). The main advantage of this system is its excellence as a test bench, since it allows testing system performance at different voltage-restricted interconnecting points. Besides, power electronics are observed to play an essential role in distributed generation systems. The applications of the developed hybrid system extend from Auxiliary Power Units (APU) in vehicles (cars, buses or trains) to Uninterruptible Power Systems (UPS) in hospitals, nursing homes, hotels, office buildings or schools. (C) 2011 Elsevier Ltd. All rights reserved.