Abstract:
The invention relates to a method for regulating a fuel cell voltage UBZ,ist in a fuel cell system, comprising a fuel cell (1), a DC/DC converter (2) coupled to the fuel cell (1) and adapted to be coupled to an energy store (3), and a control/regulation unit (4) arranged between the fuel cell (1) and the DC/DC converter (2). The method comprises the following steps: A minimum voltage value UBZ,min is determined and UBZ, Sollis selected in such a manner that UBZ, Soll =UBZ,min. The control/regulation unit (4) receives the regulating variable UBZ,ist,compares the regulating variable UBZ,ist with a predetermined desired value UBZ, SolI and determines a correcting variable IDC/DC,SoII therefrom. The control/regulation unit (4) forwards the correcting variable IDC/DC,SoII to the DC/DC converter (2). The DC/DC converter (2) impinges the fuel cell (2) with the current IBZ,ist,which limits the fuel cell voltage, depending on the correcting variable IDC/DC,SoII. The invention also relates to a fuel cell system.
Abstract:
The invention relates to a fuel cell system for mobile applications, comprising a fuel cell (1) and a DC/DC converter (2) which is coupled to the fuel cell and which can be coupled to an energy store (3). The fuel cell system is characterized in that a control/regulation unit (4) is connected to the fuel cell (1) and to the DC/DC converter (2) and that the control/regulation unit (4) comprises a performance characteristics regulator (5) that receives a value l Bz,ist of a current, a voltage value U Bz,ist from the fuel cell (1) and a value for at least one additional operating variable of the fuel cell system, that processes the received values l Bz,ist , U Bz,ist and the value for the operating variable to give a control signal and that forwards the control signal to a device (6) for controlling the operating variable. The invention also relates to an active hybrid system and to a method for the performance characteristic regulation of the fuel cell.