Comparative Study of PEM Fuel Cell Models for Integration in Propulsion Systems of Urban Public Transport

In this paper, a comparative study of three proton exchange membrane (PEM) fuel cell (FC) models is performed in order to choose the best model for its integration in the modelling of the hybrid propulsion system of a tramway. Two reduced models of PEM FC system are studied in this work: (i) a new reduced model obtained from a complete one is here presented (reduced model 1); and (ii) a reduced model very used for hybrid vehicles and portable applications (reduced model 2). These models are evaluated when integrated in the tramway hybrid system by comparing the simulated responses with that one of a complete model, which includes a detailed dynamic model of the main components of FC system. Steady state and dynamic simulations are performed in order to compare the models. Considering the external response of FC system integrated in the tramway hybrid system, both reduced models show similar results with an important reduction of computation time with respect to the complete model. However, the reduced model 1 shows better results than the reduced model 2 when representing the internal behaviour of FC system, so that this model is considered the most appropriate for propulsion system applications.