Stack operation method aimed at cell reversal prevention
AssigneeGM Global Technology Operations LLC
InventorsYeh-Hung Lai, Pinkhas A. Rapaport, Amit Nayar
Life of this patent
Estimating the term…
Abstract
A method for preventing a fuel cell voltage potential reversal including determining a relationship between the cell resistance and the current of a fuel cell stack at which a fuel cell voltage potential reversal will occur, operating the fuel cell stack according to a power demand requested, and determining the maximum cell resistance of the fuel cells in the stack. If the maximum cell resistance exceeds a threshold value for the current at which the fuel cell stack is being operated, the operation of the fuel cell stack is restricted to prevent the fuel cell voltage potential from reversing.
Claims17
A method for preventing a voltage potential reversal of a fuel cell in a fuel cell stack, said method comprising:
- determining a relationship between high frequency resistance and stack current density at which a fuel cell voltage potential reversal will occur for a predetermined type of membrane used in the fuel cells of the fuel cell stack;
- operating the fuel cell stack according to a power demand requested;
- determining the maximum cell resistance of the fuel cells in the stack;
- determining if the maximum cell resistance exceeds a predetermined cell resistance threshold value for the current at which the fuel cell stack is being operated where the predetermined cell resistance threshold value is based on the determined relationship between cell resistance and cell current at which a fuel cell voltage potential reversal will occur;
- adding a safety margin when determining if the maximum cell resistance of the fuel cells in the stack exceeds a threshold value for the current at which the fuel cell stack is being operated so as to ensure a reversal of the voltage potential of one or more of the fuel cells in the stack does not occur;
- and
- restricting the operation of the fuel cell stack by reducing the current if the maximum cell resistance exceeds the predetermined cell resistance threshold value.
A method for preventing a fuel cell voltage potential reversal, said method comprising:
- determining a relationship between cell resistance and cell current at which a fuel cell voltage potential reversal will occur for a predetermined type of membrane used in the fuel cell;
- operating the fuel cell according to a power demand requested;
- determining the cell resistance of the fuel cell;
- determining if the cell resistance of the fuel cell exceeds a predetermined threshold value for the current at which the fuel cell is operated;
- adding a safety margin when determining if the cell resistance of the fuel cell exceeds a threshold value for the current at which the fuel cell is being operated so as to ensure a reversal of the voltage potential of the cell does not occur;
- and
- restricting the operation of the fuel cell so as to prevent the fuel cell voltage potential from reversing.
A method for preventing a fuel cell voltage potential reversal of a fuel cell in a fuel cell stack, said method comprising:
- determining a relationship between cell resistance and stack current at which a fuel cell voltage potential reversal will occur for a predetermined type of membrane used in the fuel cells of the fuel cell stack;
- operating the fuel cell stack according to a power demand requested;
- determining the maximum cell resistance of the fuel cells in the stack;
- determining if the maximum cell resistance exceeds a predetermined cell resistance threshold value for the current at which the fuel cell stack is being operated, where the predetermined cell resistance threshold value is based on the determined relationship between cell resistance and cell current at which a fuel cell voltage potential reversal will occur;
- adding a safety margin when determining if the cell resistance of the fuel cells in the stack exceeds a threshold value for the current at which the fuel cell is being operated so as to ensure a reversal of the voltage potential of one or more of the fuel cells in the stack does not occur;
- and
- increasing the relative humidity and decreasing the current density of the fuel cell if the threshold value for cell resistance has been exceeded to prevent a reversal of the fuel cell voltage potential.
Dependencies are inferred from the claim text.