Control strategies of a fuel-cell hybrid tramway integrating two dc/dc converters

This paper compares two control strategies of a fuel cell (FC)-battery powered hybrid system integrating two dc/dc converters for the Metro-Centro tramway (400 kW) from Seville, Spain. Besides, modeling of each component is briefly presented. These models have been implemented in MATLAB/SIMULINK environment. A Polymer Electrolyte Membrane (PEM) FC is used in this work. The FC model characteristics are selected from a Nuvera 127 kW PEM FC. Two PEM FCs connected in parallel operate as primary energy source and a group of Ni-MH battery supplements the output of the FC during tramway acceleration or whenever else needed and provides regenerative braking energy recapture capability. Finally, the simulation results of both control configurations (Cascade and States Control Strategies) are presented for the real driving cycle of the tramway. The results demonstrate the hybrid system capability to meet appropriate driving cycle in both cases.