NOVELTY - The system has condensers mounted downstream of a fuel cell device (1) which is supplied by a compressed airflow and by a flow of a hydrogen gas or hydrogen-rich gas, where a part of gas not utilized in the fuel cell device is provided to an expansion turbine (24). The fuel cell device has a stack of individual cells assembled in series and a reformer device (2) associated to a burner (3). An oxygenation device (4) mounted in a compressed air supply conduit oxygenates the compressed airflow supplying the fuel cell device.    USE - Used for producing an electrical energy for propulsion of a motor vehicle (claimed) utilizing electrical engine.    ADVANTAGE - The oxygenation device oxygenates the compressed airflow supplying the fuel cell device, thus permitting to increase the overall yield of the electrical energy producing system. The oxygenation permits to rapidly obtain the temperature required for collecting liquid water in the condensers, thus reducing the quantity of inert gas to be cooled so that thermal management of the system is improved. The system ensures the temperature increase in an output of the burner in order to increase the quantity of energy collected on the expansion turbine and reduce the duration of the starting phase of the burner, thus permitting to rapidly obtain the desired production of the electrical energy by the system. The system facilitates the removal of heat produced in the fuel cell device and permits to maintain a constant yield of the fuel cell device in order to reduce the volume and mass of the stack of the cells, thus reducing the encumbrance and cost of the assembly of the system.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for producing electrical energy using a fuel cell device for a motor vehicle.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a general architecture of an electrical energy producing system.    Fuel cell device (1)    Reformer device (2)    Burner (3)    Oxygenation device (4)    Compressor device (22)    Expansion turbine (24)