A method for calculating voltage loss of a fuel cell is provided. The method includes sensing an open circuit voltage that is generated in a stack when the switch is opened and detecting an operation voltage and an operation current that are generated in the stack when the switch is closed. A first change graph of voltage data over time is calculated using the voltage data and current data from a time when the switch is opened in a state where the switch is closed. A first voltage of a point at which a trend line for an interval where the voltage data linearly varies with the time meets the first change graph is sensed and then an ohmic resistance voltage loss is calculated using a difference between the first voltage and the operation voltage.

A unit cell for a fuel cell stack including an anode catalyst layer separated by a polymer electrolyte membrane from a cathode catalyst layer, a first cell end plate separated by a first gas diffusion layer from the anode catalyst layer, and a second cell end plate separated by a second gas diffusion layer from the cathode catalyst layer, wherein the first cell end plate, the second cell end plate, or both include a matrix of electrically-conducting protrusions thereof.

A redox flow battery system including a cell and a monitor cell to which a same electrolyte solution is supplied; a current measuring unit that measures a current that is input to and output from the cell; a voltage measuring unit that measures an open circuit voltage of the monitor cell; and a computing unit. The computing unit includes a first processing unit, a second processing unit, and a third processing unit. The first processing unit computes an integral value obtained by integrating a current value measured by the current measuring unit, for an amount of time corresponding to a predetermined time constant. The second processing unit computes a corrected voltage value based on a measured voltage value measured by the voltage measuring unit and the integral value. And the third processing unit calculates a first state-of-charge value of the electrolyte solution from the corrected voltage value.

The invention relates to a method for detecting a leak in an energy converter system (1) containing a gas. A pressure regulator (3) is used to regulate a gas pressure in the energy converter system (1), and the pressure regulator (3) has a gas metering valve (4). The method has the following steps: a. measuring an inlet pressure (10) of the pressure regulator (3) and measuring an outlet pressure (12) of the pressure regulator (3), b. measuring an output variable (16) of the energy converter system (1) and calculating a gas requirement in the energy converter system (1) on the basis of the output variable (16) of the energy converter system (1), c. determining a first calculated flow (20) through the pressure regulator (3) on the basis of the measured inlet pressure (10) of the pressure regulator (3) and the measured outlet pressure (12) of the pressure regulator (3), d. determining a second calculated flow (22) through the pressure regulator (3) on the basis of the gas requirement, e. comparing the first calculated flow (20) with the second calculated flow (22) by generating a first comparison value (24) from the first calculated flow (20) and the second calculated flow (22), and f. determining a first threshold (26) and generating an error signal (32) if the value of the comparison value (24) is greater than the first threshold (26).

A method of estimating hydrogen crossover loss of a fuel cell system including a stack for producing power through a reaction of hydrogen serving as fuel and air serving as an oxidizer includes driving the fuel cell system; estimating a hydrogen crossover rate right after a channel of an anode is purged; determining whether a cell voltage of a fuel cell is normal; and comparing the estimated hydrogen crossover rate with a predetermined reference value based on a result of the determining of whether the cell voltage of the fuel cell is normal to determine whether a pinhole or leakage occurs. Accordingly, whether a pinhole or leakage occurs in the fuel cell system may be more effectively sensed.

A fuel cell system includes a removal treatment execution unit configured to execute an oxide layer removal treatment that removes an oxide layer generated on a catalyst of a fuel cell. The removal treatment execution unit is configured to execute the oxide layer removal treatment by adjusting a voltage of the fuel cell to be within a predetermined second voltage range lower than a predetermined first voltage range that is lower than an open-circuit voltage, when an operation of the fuel cell system shifts from a first operation, where a current value of the fuel cell is zero and the flow rate is controlled to maintain the voltage of the fuel cell within the first voltage range, to a second operation, where the current value is larger than zero and the flow rate is controlled in response to an output request to the fuel cell.

Provided is a method for inspecting a current leak of a fuel cell, which is provided with an anode electrode, a cathode electrode, and an electrolyte membrane sandwiched between the anode electrode and the cathode electrode, the method including: a first process in which a first voltage, which is a limit voltage of the electrolyte membrane, is applied to the fuel cell; a second process in which a second voltage, which is lower than the first voltage, is applied to the fuel cell after the first process; a third process in which a third voltage, which is lower than the second voltage, is applied to the fuel cell after the second process; and a determination process in which a value of a current flowing through the fuel cell in the third process is detected, and whether the detected current value is lower than a prescribed current value is determined.

A fuel cell system includes first and second fuel cells, first and second coolers cooling coolant, first and second coolant supply path from the coolers to the fuel cells, first and second coolant discharge paths from the fuel cells to the coolers, a detour path connecting the first coolant supply path and the first coolant discharge path bypassing the first cooler, an adjusting device adjusting a flow rate of coolant of the detour path, first and second connection paths connecting the coolant supply paths and the coolant discharge paths, first and second opening/closing valves in the connection paths, and a controller configured to, when there is a possibility of flooding, suspend power generation of the first fuel cell and control the adjusting device or the first cooling device such that a temperature of the coolant of the first fuel cell increases, and open the opening/closing valves.

Systems and methods for operating an electric energy storage device are described. The systems and methods may generate a state of charge estimate that is based on negative electrode plating. An overall state of charge may be determined from the state of charge estimate that is based on negative electrode plating and a state of charge estimate that is not based on negative electrode plating.

A method for calculating voltage loss of a fuel cell is provided. The method includes sensing an open circuit voltage that is generated in a stack when the switch is opened and detecting an operation voltage and an operation current that are generated in the stack when the switch is closed. A first change graph of voltage data over time is calculated using the voltage data and current data from a time when the switch is opened in a state where the switch is closed. A first voltage of a point at which a trend line for an interval where the voltage data linearly varies with the time meets the first change graph is sensed and then an ohmic resistance voltage loss is calculated using a difference between the first voltage and the operation voltage.