Fuel cell-battery hybrid system for transport applications

This paper presents a fuel cell-battery powered hybrid system for transport applications, more specifically for a tramway. It uses a Polymer Electrolyte Membrane (PEM) fuel cell (FC) as primary energy source and a Ni-MH battery as secondary energy source, which serves as a supplement to the FC during the driving cycle. The hybrid system supplies the power consumption of the auxiliary services and the traction system, which is composed of four traction induction motor drives. The energy management system (EMS) of the hybrid tramway fixes the reference signals for: 1) the FC dc/dc boost converter in order to accurately distribute power between two electrical sources; 2) the electric motor drives; 3) energy dissipation in the braking chopper when required during regenerative braking. The proposed hybrid system is assessed for a real driving cycle. The results show the hybrid system capability to allow the tramway to properly follow the driving cycle.