Fuel cells are one of the most promising energy sources, especially for onboard applications. However, fuel cells present several drawbacks, such us slow dynamic response, loaddependent voltage and uni-directional power flow, that produce an inappropriate vehicle operation. So, secondary energy sources and power converters must be implemented in order to satisfy fast changes in the current load and to store the energy delivered by the load if regenerative braking is intended. Taking into account the number and nature of the power converters, loads, secondary energy sources, and the possibilities for the control strategies, the design of a power distribution architecture based on fuel cells for transport applications is a complex task. In order to address these architectures, modeling and simulation design tools at system level are essential.This paper proposes a complete fuel cell black-box model which reproduces the behavior of a commercial fuel cell with overshooted transient response. The identification technique applied to parameterize the model components, based on manufacturer's datasheets and a test based on load steps, is explained thoroughly. Additionally, if only the fuel cell frequency response and manufacturer's datasheet are available, an alternative parameterization methodology based on the fuel cell frequency response is presented. The fuel cell black-box model is validated experimentally using a commercial PEM (Proton Exchange Membrane) fuel cell. Two different parameterizations are carried out with the aim of verifying the robustness of both the fuel cell model and the proposed identification methodology. Index Terms-black-box model, fuel cell, identification methodology, power distribution architecture, system level model, transport, vehicles I. INTRODUCTION UEL cells are considered as one of the most attractive distributed energy sources, due to their reliability, the low or none polluting emissions and their low maintenance requirements [1]. A fuel cell is an electrochemical device where a continuous catalytic reaction of hydrogen and oxygen takes place in the presence of an electrolyte. Its behavior is Manuscript received October 8, 2013.