Management of the operation of a system for producing electric power from hydrogen and hydrogen from electric power

Abstract

A system for producing electric power from hydrogen and hydrogen from electric power, comprising: a reversible electric power-hydrogen conversion stage comprising a fuel cell stack to produce electric power from stored hydrogen and an electrolytic cell stack to produce hydrogen from electric power; a hydrogen pressure modification stage to modify the pressure of hydrogen supplied to or produced from the reversible electric power-hydrogen conversion stage; an electric power management and conditioning stage to condition electric power from/to the reversible electric power-hydrogen conversion stage; and a management stage to differentially manage the operation of the reversible electric power-hydrogen conversion stage, the hydrogen pressure modification stage and the electric power management and conditioning stage according to whether the system produces electric power from hydrogen or hydrogen from electric power and on a user-settable operation management strategy.

1 . A system ( 1 ) for producing electric power from hydrogen and hydrogen from electric power, comprising:
 a reversible electric power-hydrogen conversion stage ( 2 ) comprising a fuel cell stack ( 7 ) to produce electric power from stored hydrogen and an electrolytic cell stack ( 9 ) to produce hydrogen from electric power;   a hydrogen pressure modification stage ( 3 ) to modify pressure of hydrogen from/to the reversible electric power-hydrogen conversion stage ( 2 );   an electric power management and conditioning stage ( 4 ) to condition electric power from/to the reversible electric power-hydrogen conversion stage ( 2 ); and   a management stage ( 5 ) to differentially manage operation of the reversible electric power-hydrogen conversion stage ( 2 ), the hydrogen pressure modification stage ( 3 ) and the electric power management and conditioning stage ( 4 ) based on whether the system ( 1 ) is operated to produce electric power from hydrogen or hydrogen from electric power and on a user-settable operation management strategy.   
     
     
         2 . The system ( 1 ) according to  claim 1 , wherein said hydrogen pressure modification stage ( 3 ) essentially consists of passive and active components interconnected to one another. 
     
     
         3 . The system ( 1 ) according to  claim 1 , wherein, when operated to produce electric power from hydrogen, the management stage ( 5 ) is configured to:
 cause the hydrogen pressure modification stage ( 3 ) to reduce stored hydrogen pressure from a storage pressure to a use pressure;   cause the reversible electric power-hydrogen conversion stage ( 2 ) to convert the stored hydrogen to electric power;   cause the electric power management and conditioning stage ( 4 ) to manage the reversible electric power-hydrogen conversion stage ( 2 ) by imposing voltage and current values thereof according to preset logics which take account of voltage and current transients acceptable by the reversible electric power-hydrogen conversion stage ( 2 ), whereby the latter supplies electric power in the form requested by an electric load or a local electric power supply network to which the produced electric power is to be supplied.   
     
     
         4 . The system ( 1 ) according to  claim 1 , wherein, when operated to produce electric power from hydrogen, the management stage ( 5 ) is further configured to:
 cause a communication unit ( 15 ) to communicate system activation and residual autonomy thereof to a remote control station.   
     
     
         5 . The system ( 1 ) according to  claim 1 , wherein, when operated to produce hydrogen from electric power, the management stage ( 5 ) is configured to:
 determine when the system ( 1 ) is to be activated based on the following:   availability and presence of electric power in situ;   stored hydrogen amount; and   possible requests by a remote control station;   cause the reversible electric power-hydrogen conversion stage ( 2 ) to convert electric power to hydrogen;   cause the electric power management and conditioning stage ( 4 ) to control the reversible electric power-hydrogen conversion stage ( 2 ) based on a user-settable control strategy to achieve one or more of the following targets:
 a) fill the hydrogen storage in the shortest possible time; 
 b) fill the hydrogen storage with the highest possible efficiency; 
 c) fill the hydrogen storage using all of the available electric power; and 
 d) ensure the filling of the hydrogen storage taking account of the programmed electric power cut-offs in the local electric power supply network. 
   
     
     
         6 . The system ( 1 ) according to  claim 5 , wherein:
 to fill the hydrogen storage in the shortest possible time, the electric power management and conditioning stage ( 4 ) is configured to force the reversible electric power-hydrogen conversion stage ( 2 ) to operate at the maximum possible voltage to have the highest hydrogen flow rate at a given reference temperature;   to fill the hydrogen storage with the highest possible efficiency, the electric power management and conditioning stage ( 4 ) is configured to force the reversible electric power-hydrogen conversion stage ( 2 ) to operate at the minimum admissible electric voltage;   to fill the hydrogen storage using all of the available electric power, the electric power management and conditioning stage ( 4 ) is configured to cause the reversible electric power-hydrogen conversion (stage  2 ) to operate in an operation point corresponding to the maximum hydrogen flow rate achievable with the available electric power; and   to ensure the filling of the hydrogen storage taking account of the programmed electric power cut-offs in the local electric power supply network, the electric power management and conditioning stage ( 4 ) is configured to cause the reversible electric power-hydrogen conversion stage ( 2 ) to operate in an operation point determined as the average of operation points computed integrally based on the available electric power and the available time.   
     
     
         7 . The system ( 1 ) according to  claim 5 , wherein the management stage ( 5 ) is configured to dynamically compute electric voltage and current values to be supplied to the electrolytic cell stack ( 9 ) based on the user-settable control strategy and electric quantities measured in the system ( 1 ). 
     
     
         8 . A management stage ( 5 ) for a system ( 1 ) for producing electric power from hydrogen and hydrogen from electric power, according to  claim 1 . 
     
     
         9 . A software loadable in a management stage ( 5 ) of a system ( 1 ) for producing electric power from hydrogen and hydrogen from electric power, and designed to cause, when executed, the management stage ( 5 ) to become configured as claimed in  claim 1 .