A fuel cell system has a fuel cell unit that includes a fuel cell stack comprising a cathode and an anode, a cathode recirculation passage configured to divert a cathode exhaust flow to a cathode inlet line when reduction in oxygen partial pressure in an air flow fed to the cathode via the cathode inlet line is required, and an inert gas generating system configured to generate an inert gas to be supplied to the cathode inlet line when further reduction in oxygen partial pressure in the air flow is required. When the fuel cell system is or is expected to be operating with a reduced power demand, a value of a power output that is requested from the fuel cell system is compared to at least one threshold power level to determine whether to divert the cathode exhaust flow and/or the inert gas to the cathode inlet line.

The present disclosure pertains to a system (5) comprising a plurality of power converters (20-1 to 20-n) configured, via a processing device (30), to balance heat from a plurality of fuel cell stacks (10-1 to 10-n). Some embodiments may: set one or more parameter values of one of the power converters (20-1) located at the output of one of the plurality of stacks (10-1) such that the one stack preferentially provides power to a load; determine a heat power of the one stack (10-1) and of one or more other stacks of the plurality of stacks (10-2 to 10-n), each of the heat powers being determined based on a voltage and current that are determined at the input of the respective power converter (20-1 to 20-n); determine whether the heat power of the one stack (20-1) satisfies a criterion; and responsive to a determination that the heat power of the one stack satisfies the criterion, set one or more parameter values of each of the power converters (20-2 to 20-n) located at the output of the one or more other stacks such that the determined heat power of each of the one or more other stacks (10-2 to 10-n) more closely matches the determined heat power of the one stack (10-1).

A method for operating a power system in the present disclosure includes the step of planning an output of a fuel cell system in such a way as to make up a difference between power demand and an output of a solar power generation system. In the step, if a charge level of a storage battery system is higher than or equal to an upper limit value smaller than 100%, first correction, in which the plan is corrected in such a way as to reduce the output of the fuel cell system, is performed and/or if the charge level of the storage battery system is lower than or equal to a lower limit value larger than 0%, second correction, in which the plan is corrected in such a way as to increase the output of the fuel cell system, is performed.

A fuel cell electric vehicle (FCEV) includes an electric traction motor configured to drive the FCEV and generate power through regenerative braking, a high voltage (HV) battery system including a HV bus and a HV battery configured to power the electric traction motor, and a fuel cell stack (FCS) configured to generate electricity to recharge the HV battery and/or power the electric traction motor. A powertrain control system for preventing over-voltage of the HV bus and HV battery includes a controller having one or more processors configured to control (i) a fuel cell power limit of the FCS, and (ii) a regenerative braking power limit of the electric traction motor. The controller is programmed to measure a voltage of the HV battery system, and selectively limit the fuel cell power limit and/or the regenerative braking power limit when the measure voltage exceeds a predetermined threshold.

A fuel cell ship includes a fuel cell compartment in which a fuel cell is installed, a tank compartment in which a fuel tank is installed, a fuel supply pipe through which fuel is supplied from the fuel tank to the fuel cell, and a control unit. The fuel supply pipe includes at least two shutoff valves. Fuel gas detectors that detect a fuel gas being in a gaseous state of the fuel are each installed in the compartments. If at least one of the fuel gas detectors detects that a concentration of the fuel gas is equal to or greater than a predetermined standard value, the control unit controls to close a shutoff valve in a compartment out of the tank compartment and the fuel cell compartment, where the fuel gas detector having detected the concentration equal to or greater than the standard value is installed.

A method for controlling a carbon dioxide utilization in a fuel cell assembly includes: measuring a voltage across the fuel cell assembly; determining an estimated carbon dioxide utilization of the fuel cell assembly based on at least the measured voltage across the fuel cell assembly by determining an expected voltage of the fuel cell assembly based on at least a temperature of the fuel cell assembly, a current density across the fuel cell assembly, a fuel utilization of the fuel cell assembly, and a cathode oxygen utilization of the fuel cell assembly; determining the estimated carbon dioxide utilization based on a comparison between the measured voltage and the determined expected voltage; comparing the determined estimated carbon dioxide utilization to a predetermined threshold utilization; and upon determining that the determined estimated carbon dioxide utilization is higher than the predetermined threshold utilization, reducing the carbon utilization of the fuel cell assembly.

A power generation plan revision method according to the present disclosure includes: receiving a power generation plan for a fuel cell device provided with a plurality of fuel cell power generation units; and revising the received power generation plan for the fuel cell device so as to advance a timing of changing the power-generating number of the fuel cell power generation units relative to a timing of changing from a previous unit period to a next unit period in the power generation plan, according to the magnitude of a change in the output of the fuel cell device when changing from the previous unit period to the next unit period.

A fuel cell hydrogen gas circuit device and a control method thereof are provided. The device includes a hydrogen cylinder, a hydrogen pressure stabilizing chamber, an injector, a hydrogen-water separator, and a hydrogen circulation pump. The hydrogen cylinder is connected to the first inlet of the injector through the hydrogen pressure stabilizing chamber, and the outlet of the injector is connected to the inlet of the fuel cell stack. The outlet of the fuel cell stack is connected to the hydrogen-water separator, and the gas outlet of the hydrogen-water separator is connected to the second inlet of the injector. The hydrogen-water separator is also connected to the inlet of the hydrogen circulation pump, and the outlet of the hydrogen circulation pump is connected to the inlet and outlet of the fuel cell stack through pipelines. It can effectively alleviate hydrogen starvation under loading conditions, water flooding, and platinum degradation.

An embodiment fuel cell device includes a fuel cell, a power controller configured to convert a magnitude of a stack voltage output from the fuel cell and to output the stack voltage having the converted magnitude to a load, and a junction box including a bypass diode that includes an anode coupled to the stack voltage and to a voltage input terminal of the power controller and a cathode coupled to a voltage output terminal of the power controller and to the load, wherein the voltage output terminal of the power controller is configured to carry a voltage having the converted magnitude.

The electric power supply device supplies electric power to a work machine. The electric power supply device includes a fuel cell and a utility connecting section for transferring utility to be utilized for an operation of a fuel cell between the work machine and the electric power supply device. A control device for controlling the electric power supply device for supplying electric power to the work machine includes a rated capability obtaining section for obtaining information indicating a rated value of a capability with which the work machine supplies the utility to the fuel cell in response to the electric power supply device being mounted in the work machine, or the electric power supply device being able to utilize the utility, and an operating condition determining section for determining an operating condition of the electric power supply device based on the rated value.