This invention relates to fuel cell unit for use in aggregating fuel cells, particularly useful for use when fuel cells are connected in parallel. Improving the management of fuel cell outputs across a plurality of aggregated fuel cells improves efficiency of the fuel cells. The invention relates to a fuel cell unit comprising a fuel cell and a regulating voltage converter, and further relates to a fuel cell module comprising a plurality of fuel cell units connected in parallel.

A vehicle system of the present invention includes: a motor configured to drive a vehicle; a high voltage storage device connected to the motor and configured to supply the motor with power; a fuel cell connected to the high voltage storage device and configured to charge the high voltage storage device; and a low voltage storage device connected to the fuel cell. The vehicle system includes: a bidirectional first voltage converter interposed between the fuel cell and the high voltage storage device, and configured to adjust a voltage at either of the fuel cell or the high voltage storage device and to supply power to the other; and a second voltage converter interposed between the fuel cell and the low voltage storage device, and configured to adjust a voltage at the low voltage storage device and to apply the adjusted voltage to the fuel cell. The vehicle system is characterized in that the vehicle system includes a bidirectional third voltage converter interposed between the high voltage storage device and the low voltage storage device, and configured to adjust a voltage at either of the high voltage storage device or the low voltage storage device and to supply power to the other.

A method of operating a fuel cell system which includes a plurality of fuel cells and a plurality of auxiliary components located in at least one cabinet, includes monitoring, by a control unit, a parameter of the fuel cell system, determining whether the parameter has violated a threshold, and varying an auxiliary bus voltage provided to the plurality of auxiliary components connected to a common auxiliary bus by a first amount in response to determining that the parameter has violated the threshold.

A fuel cell charging system includes a fuel cell stack having a first operating direct current (DC) voltage between fuel check stack terminals, a high voltage system operating at a first DC operating voltage different than and generally higher than the first operating voltage of the fuel cell stack, a boost converter in electrical connection with the fuel cell stack and the high voltage system, and a stack charging component that applies a second DC operating voltage, generally of lower value than that of the first normal operating voltage, to the fuel cell stack. The boost converter transfer electrical power from the fuel cell stack to the high voltage system during fuel cell operation. Characteristically, the second DC operating voltage applied to the fuel cell stack terminals is typically lower in value than that of the first DC operating voltage of both the fuel cell stack and the HV electrical system and is stepped down from the first DC operating voltage of the HV electrical system.

A fuel cell system includes a control unit configured to control for switching a secondary battery step-up converter between a step-up operation mode and a step-up stop mode. The control unit is configured to obtain a correlation value that correlates with a dischargeable electric power of a secondary battery, prohibit the step-up stop mode when a required voltage of a load is lower than an output voltage of the secondary battery and the correlation value falls within a prohibition range in which the step-up stop mode is prohibited, and execute the step-up stop mode when the required voltage is lower than the output voltage of the secondary battery and the correlation value falls outside the prohibition range.

A cathode oxygen depletion (COD) control method is provided. The method includes determining whether a COD heater operates and calculating power generation and power consumption when the COD heater operates. Additionally, the power consumption is adjusted by comparing the calculated power generation and power consumption.

A fuel cell system including a hydrogen tank configured to store hydrogen supplied to a fuel cell stack, a heater configured to heat the hydrogen tank, a cooler configured to cool the hydrogen tank by circulating cooling water, and a controller configured to adjust a temperature of the hydrogen tank by controlling the heater and the cooler responsive to a measured temperature of the hydrogen tank.

Provided are a recovery control system of a fuel cell and a method thereof. The recovery control system includes the fuel cell, a hydrogen supplier configured to supply hydrogen to the fuel cell, an air supplier configured to supply air to the fuel cell, an abnormality sensing unit configured to calculate a difference between a reference cell voltage predetermined depending on an output current of the fuel cell and a measured cell voltage of unit cells and to sense abnormality of air supply to a fuel cell stack based on the calculated difference between the reference cell voltage and the measured cell voltage or change in the difference, and a recovery controller configured to control the air supplier so as to increase a flow rate of air supplied to the fuel cell stack based on the change in the difference, when the abnormality sensing unit senses abnormality of air supply.

A fuel battery system includes a fuel battery, an electric storage, a voltage adjuster, a pump, an abnormity detector, and circuitry. The fuel battery generates electricity using fuel gas and oxidant gas. The voltage adjuster is connected to at least one of the fuel battery and the electric storage. The voltage adjuster is configured to adjust voltage output from the fuel battery or the electric storage to output the adjusted voltage to a load. The pump supplies the oxidant gas to the fuel battery using electric power output from at least one of the fuel battery and the electric storage. The voltage adjuster is connected between the fuel battery and the pump. The abnormity detector detects abnormity in the voltage adjuster. The circuitry is configured to restrict the electric power supplied to the pump in a case where the abnormity detector detects the abnormity in the voltage adjuster.

A hydrogen generation system for generating hydrogen and electrical power includes a power supply, a reformer-electrolyzer-purifier (REP) assembly including at least one fuel cell including an anode and a cathode separated by an electrolyte matrix, at least one low temperature fuel cell, and a hydrogen storage. The at least one fuel cell is configured to receive a reverse voltage supplied by the power supply and generate hydrogen-containing gas in the anode of the at least one fuel cell. The at least one low temperature fuel cell is configured to receive the hydrogen-containing gas output from the REP assembly. The at least one low temperature fuel cell is configured to selectably operate in a power generation mode in which the hydrogen-containing gas is used to generate electrical power and a power storage mode in which the hydrogen-containing gas is pressurized and stored in the hydrogen storage.