A vehicle power system including a fuel cell auxiliary power unit for providing clean, efficient power to a vehicle. The system generally includes a fuel cell with a first DC output and a heat output, a pressure vessel adapted to contain and provide pressurized hydrogen to the fuel cell, an electrical storage unit with a DC input coupled to the first DC output of the fuel cell. The electrical storage unit also has a second DC output. An inverter is coupled to the second DC output of the electrical storage unit to receive power, the inverter having a first AC output. The system can provide heat, AC power, and DC power to the vehicle.

An apparatus for splitting the power of fuel cell systems in a vehicle comprises: a first fuel cell system and at least one further fuel cell system, which are configured to convert hydrogen and oxygen into water in order to generate electrical energy therefrom, and a controller unit, which is configured to actuate the first fuel cell system and the further fuel cell system with an electrical signal. The apparatus is configured to actuate the first fuel cell system and the further fuel cell system with the electrical signal in time offset fashion.

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 ship includes a propulsion device that generates propulsive force on a hull by electric power, an electric power supply unit that supplies the electric power to the propulsion device, and a degradation rate control unit that adjusts a degradation rate. The electric power supply unit includes a plurality of fuel cells that generate electric power by an electrochemical reaction of fuel and at least one storage battery.

A fuel cell system for air vehicles, wherein the fuel cell system comprises: a fuel cell, a fuel gas system for supplying fuel gas to the fuel cell, a potential sensor, and a controller; wherein the fuel gas system comprises a fuel gas supplier; wherein the controller determines whether or not a potential of the fuel cell measured by the potential sensor, is a reversal potential; and wherein, when the controller determines that the potential of the fuel cell is a reversal potential, the controller increases a fuel gas supply from the fuel gas supplier to the fuel cell.

A redox flow battery system includes at least two battery modules, a bidirectional converter, and a controller. The battery modules are connected in series and are connected to the converter. Each battery module has a cell array with a plurality of redox flow cells and a tank device for storing electrolyte and supplying electrolyte to the cell array. The battery system further includes a DC-to-DC converter for each battery module, one terminal of each DC-to-DC converter being connected to one battery module, and a second terminal of each DC-to-DC converter being connected to a common DC bus. An additional converter is connected to the DC bus. The controller is connected to the additional converter and to the DC-to-DC converters in such a way that the controller can control the additional converter and the DC-to-DC converters.

A catalyst deterioration suppression device includes: a first device obtaining a fuel cell voltage V (=catalyst voltage V.sub.cat) as a variable to estimate a response speed (time constant τ) at which a coverage ratio of an oxide film of catalyst particles contained in a fuel cell cathode changes; a second device reading out a time constant τ.sub.t corresponding to the voltage V at a current time t from a pre-made map A representing a relationship between the voltage V and the time constant τ and corresponding to the catalyst particles; a third device generating a continuous-time type dynamic filter F(s, τ) by using the time constant τ.sub.t and converting the continuous-time type dynamic filter F(s, τ) to a discrete-time type dynamic filter F(z, τ); and a fourth device inputting a target voltage Vr to the discrete-time type dynamic filter F(z, τ) and outputting a corrected target voltage V.sub.r-fil.

A fuel cell system that can improve an operating efficiency while minimizing an increase in cost for a configuration is provided. A fuel cell system (10) includes a fuel cell stack (11), an air pump (13), and an electric power control unit (15). The air pump (13) is connected to an output terminal of the fuel cell stack (11). The air pump (13) is configured to supply air as an oxidizing agent gas to the fuel cell stack (11). The electric power control unit (15) includes a first circuit unit (31) and a second circuit unit (32). The first circuit unit (31) is connected to the output terminal of the fuel cell stack (11) and is configured to perform step-up electric power conversion on an input from the fuel cell stack (11). The second circuit unit (32) is configured to perform bidirectional electric power conversion for stepping-up an input from the fuel cell stack (11) and for stepping-down an output to the air pump (13).

A fuel cell system includes a plurality of fuel cell units each configured to generate lower-voltage DC power. The fuel cell system includes a plurality of DC-DC converters each electrically connected to each of the fuel cell units and configured to convert the lower-voltage DC power to higher-voltage DC power. The fuel cell system includes a primary load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output a primary load. The fuel cell system includes an auxiliary load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output an auxiliary load.

A fuel cell system includes: an external load connected to a fuel cell; an electric power adjusting unit configured to adjust a generated electric power of the fuel cell in accordance with electric power consumption of the external load; a humidity control unit configured to control humidity of an electrolyte membrane in the fuel cell on the basis of the generated electric power of the fuel cell; an output voltage detecting unit configured to detect an output voltage of the fuel cell; and a cross leakage determining unit configured to cause the humidity control unit to increase the humidity of the electrolyte membrane when the fuel cell generates the electric power, the cross leakage determining unit being configured to determine whether a cross leakage amount increases or not on the basis of a change in the output voltage at that time.