Disclosed are a method and a system for controlling an output current of a fuel cell stack. The method of controlling the output current of the fuel cell stack, whereby the output current is controlled by using a data map configured with a limited output current according to a temperature of a fuel cell coolant, includes: deriving an average cell voltage value and a minimum cell voltage value of a plurality of cells constituting the fuel cell stack; correcting the data map by using the derived average cell voltage value and the derived minimum cell voltage value; and limiting the output current of the fuel cell according to the corrected data map.

An electrical system includes a stack (3) of electrochemical cells (5), a power converter (9) electrically connected to the stack (3), a voltage comparator (7) for comparing the voltage at the terminals of at least one group of at least one electrochemical cell (5) of the stack (3) to a threshold voltage, and a control module (11) for controlling the converter (9). The control module (11) includes a generator (74) for generating a control instruction for controlling the converter (9) and a transmission member (76) for transmitting the control instruction to the converter (9). The voltage comparator (7) is suitable for transmitting a signal to the transmission member (76). The signal consists of a first instruction from an instruction for transmitting and an instruction for blocking the control instruction when the compared voltage is higher than the threshold voltage, and a second instruction from the instructions for transmitting and blocking the control instruction when the compared voltage is lower than or equal to the threshold voltage.

There is provided a fuel cell system having a fuel cell, which determines whether an operating state thereof is a low-temperature-startup operation or a normal-running operation and performs recovery control for increasing a concentration gradient of water in an electrolyte membrane of the fuel cell to be greater than that in the normal-running operation when it is determined that the operating state is the low-temperature-startup operation.

Systems, methods, and devices of the various embodiments provide a hardware and software architecture enabling electrochemical impedance spectroscopy (EIS) to be performed on multiple electrochemical devices, such as fuel cells, at the same time without human interaction with the electrochemical devices and to use EIS to dynamically monitor the performance of a fuel cell system. Embodiment methods may include determining an impedance of a set of fuel cells using electrochemical impedance spectroscopy, determining an ohmic polarization of the set of fuel cells from the impedance, determining a concentration polarization of the set of fuel cells from the impedance, comparing the ohmic polarization of the set of fuel cells to a first threshold, comparing the concentration polarization of the set of fuel cells to a second threshold, and initiating a corrective action when the ohmic polarization is above the first threshold or when the concentration polarization is below the second threshold.

A fuel cell system and method, the system including power generating fuel cells disposed in a stack, each power generating fuel cell including an anode, a cathode, and an electrolyte, a sensing fuel cell including an anode, a cathode, and an electrolyte, and a fuel processor configured to purify a fuel provided to the power generating fuel cells and the sensing fuel cell. The anode of the sensing fuel cell is thinner than the anodes of the power generating fuel cells.

An operation control system of a fuel cell is provided. The system includes a fuel cell stack and a motor connected to the fuel cell stack via a main bus end to receive power. A booster is disposed between a load and the fuel cell stack of the main bus end to adjust an output voltage of the fuel cell stack. A high-voltage battery is connected between a load and the booster of the main bus end and a voltage sensor is connected between the booster and the fuel cell stack of the main bus end to measure an output voltage of the fuel cell stack.

A controlling device of a fuel cell system with multiple stack towers and a controlling method thereof are provided. The controlling device comprises a temperature sensing equipment, a processor and a pulse width modulation circuit. The fuel cell system comprises multiple fuel cell stacks. The controlling method further comprises: calculating an average temperature of the fuel cell stacks based on the temperatures of the fuel cell stacks by the temperature sensing equipment; determining whether differences between the average temperature and the temperatures of the fuel cell stacks fall within a preset range of average temperature difference by the processor, and adjusting an output current of at least one of the fuel cell stacks by the pulse width modulation circuit commanded by the processor when the difference between the average temperature and the temperature of the at least one fuel cell stack falls outside the preset range of average temperature difference.

Provided is a two-power-supply load driving fuel cell system capable of improving the durability of the fuel cell and the power efficiency of the system. Even if the variation of a load terminal voltage occurs, the variation of the output terminal of an FC can be suppressed due to the high-speed operation of an FCVCU including an SiC-FET, enabling the durability of the FC to be ensured. In addition, since IGBTs are employed in a BATVCU having large average passing power, the power loss of a fuel cell system can be reduced. It is therefore possible to construct a system that takes advantage of the characteristics of the switching elements used in the FCVCU and the BATVCU.

The present disclosure generally relates to systems and methods for using an energy storage device to assist a venturi or an ejector in a fuel cell or fuel stack system.

A fuel cell system includes a plurality of fuel cell stacks, a power generation control unit that controls power generation of the plurality of fuel cell stacks based on a required power for the plurality of fuel cell stacks, and a refreshing control unit configured to perform a refreshing process of decreasing a voltage on the plurality of fuel cell stacks. The refreshing control unit performs the refreshing process on the first fuel cell stack when the required power changes from a state in which the required power is less than a first predetermined value to a state in which the required power is equal to or greater than the first predetermined value and when the required power is in a range which is equal to or greater than the first predetermined value and less than the second threshold value.