To provide a fuel-efficient fuel cell system configured to eliminate flooding in a fuel-based gas flow path, etc. The fuel cell system is a fuel cell system comprising a first fuel cell stack, a second fuel cell stack, a fuel gas supplier, a first supply flow path, a first circulation flow path, a second supply flow path, a second circulation flow path, a first bypass flow path which includes a first on-off valve, a second bypass flow path which includes a second on-off valve, a temperature detector, a current detector, a voltage detector and a controller.

An online impedance spectrum measuring device and method for a vehicle-mounted hydrogen fuel cell includes: a controllable alternating current source, configured to apply a sinusoidal alternating signal; a cell voltage signal preceding-stage measuring circuit, configured to select to communicate with one monocell via a voltage signal gating circuit; a current sensor and a cell current signal preceding-stage measuring circuit connected with the current sensor; and a signal conditioning and amplifying circuit, a multi-channel simultaneous sampling analog-digital conversion circuit, a digital signal processor and an upper computer, which are connected in sequence, wherein the signal conditioning and amplifying circuit is connected to the cell voltage signal preceding-stage measuring circuit and the cell current signal preceding-stage measuring circuit, separately; and the upper computer is connected with the controllable alternating source and the voltage signal gating circuit.

A fuel cell system including: a fuel cell group; a refrigerant distribution passage; a pre-distribution refrigerant flow rate acquiring unit configured to acquire a first outlet temperature flow rate; a first outlet temperature detecting unit that is configured to detect a first outlet temperature; a voltage acquiring unit configured to acquire at least a first voltage that is a voltage of the first fuel cell; a current acquiring unit configured to acquire at least a first current; and a controller that calculates a first individual supply flow rate of the first fuel cell on the basis of the first voltage, the first current, and the first outlet temperature, and calculates a second individual supply flow rate of at least one second fuel cell other than the first fuel cell on the basis of the first individual supply flow rate and the pre-distribution refrigerant flow rate.

A system for capturing carbon dioxide in flue gas includes a fuel cell assembly including at least one fuel cell including a cathode portion configured to receive, as cathode inlet gas, the flue gas generated by the flue gas generating device or a derivative thereof, and to output cathode exhaust gas and an anode portion configure to receive an anode inlet gas and to output anode exhaust gas, a fuel cell assembly voltage monitor configured to measure a voltage across the fuel cell assembly, and a controller configured to receive the measured voltage across the fuel cell assembly from the fuel cell assembly voltage monitor, determine an estimated carbon dioxide utilization of the fuel cell assembly based on the measured voltage across the fuel cell assembly, and reduce the carbon dioxide utilization of the fuel cell assembly when the determined estimated carbon dioxide utilization is above a predetermined threshold utilization.

Methods and apparatus for detecting electrical short circuits in fuel cell stacks are provided. The methods involve supplying a reactant and an inert gas to a fuel cell stack and measuring the open circuit voltage of fuel cell assemblies in the fuel cell stack. The sensitivity of the methods can be adjusted to detect an electrical short circuit having a resistance at or below a particular threshold short-circuit resistance value, by using a suitable reactant concentration in the method. The methods can include determining a set-point reactant concentration that can be used to detect an electrical short circuit having a resistance at or below a particular threshold short-circuit resistance value.

A fuel cell system includes a fuel cell stack, a first discharger, an opening-and-closing valve, a second discharger, a voltage detector, and a controller.

A power supply system including a stack of fuel cells, a device for regulating the voltage at the poles of the stack which includes a resistive load connected between the poles of the stack for generating a voltage drop between them and a controlled switch inserted in series with the resistive load, which can be actuated between an open configuration and a closed configuration.

An electrical energy supply system for mobile platforms includes an electrical arrangement having at least two fuel cell units in a serial interconnection in relation to one another in the electrical arrangement and configured to provide an electrical voltage to supply at least one consumer. The electrical energy supply system includes a ground unit which is assigned an electrical reference potential, and at least two control units, which are each assigned to at least one of the fuel cell units, wherein each of the at least two control units is configured to detect an electrical voltage of the assigned fuel cell unit in relation to the reference potential. An aircraft is disclosed having an electrical energy supply system.

The present invention provides a fuel cell stack protection method, a fuel cell stack protection device and a fuel cell power supply system. The method comprises: determining whether a load-dump failure occurs to the fuel cell; controlling the bleeder circuit connected to the output ends of a DC-DC circuit in the fuel cell so as to discharge the DC-DC circuit when a load-dump failure occurs to the fuel cell. When a load-dump failure occurs to the fuel cell, the bleeder circuit connected to the output ends of the DC-DC circuit in the fuel cell is turned on to discharge the DC-DC circuit so that the DC-DC circuit in the fuel cell can continue to output a current, thus preventing the voltage of a fuel cell stack from rising abruptly because of a load-dump failure and preventing any damage caused by a load-dump failure to the fuel cell stack

To provide a fuel cell system configured to appropriately measure the AC impedance of a fuel cell. A fuel cell system wherein a controller controls ON and OFF of switches of n phases; wherein the controller monitors current values of coils; the controller operates the switches of the n phases at different phases; wherein the controller operates duty ratios of the switches of the n phases with periodically increasing and decreasing them, and the controller measures an AC impedance of a fuel cell from a current waveform of and a voltage waveform of the fuel cell; and wherein, when the controller determines that a predetermined condition 1 is met, the controller makes amplitudes which increase and decrease the duty ratios large compared to other operating conditions.