According to one embodiment of the present invention, the method for controlling the pump speed of a redox flow battery for transferring an electrolyte stored in an electrolyte tank to a cell stack comprises the steps of: measuring the input power and/or the output power of the redox flow battery; measuring the charging power and/or the discharging power of the redox flow battery; calculating the power loss of the redox flow battery by using the difference between the input power and the charging power, or the difference between the output power and the discharging power; and adjusting the pump speed according to the power loss.

A rational fuel-cell power following strategy is made according to values such as vehicle fuel-cell power, battery power, and SOC (state of charge) of a lithium-ion battery; in the same time window, effects of different fuel-cell power growth rates on SOC of the lithium-ion battery are tested according to vehicle requirements; and at the same fuel-cell growth rate, effects of different time windows on SOC of the lithium-ion battery are tested according to vehicle requirements; a proper time window and a proper fuel-cell power change rate are found, so that the SOC value of the lithium-ion battery fluctuates within a certain range. The present invention can achieve a good operation mode of power distribution between the fuel cell and the lithium-ion battery, ensuring rational utilization of resources, thereby extending the application range of the lithium-ion battery to the maximum extent.

A method of shutting down a fuel cell system includes a fuel cell includes generating power via an electrochemical reaction between a fuel gas and an oxidant gas. A shutdown command is output to the fuel cell to stop generating power. The fuel cell is controlled to continue generating power during an oxygen consumption process to consume oxygen in the oxidant gas remaining in a cathode system of the fuel cell even when the shutdown command is output to the fuel cell. At least one of voltage, current, and power output from the fuel cell is detected during the oxygen consumption process. Whether an abnormality occurs during the oxygen consumption process is determined based on at least one of the voltage, the current, and the power. The fuel cell is controlled to stop generating power during the oxygen consumption process when it is determined that abnormality occurs.

Disclosed is a method of controlling an air supply system for a fuel cell. The air supply system includes a fuel cell stack, an air channel to supply air to an inlet of the fuel cell stack, a gas adsorption unit disposed on the air channel and configured to adsorb oxygen contained in air introduced into the air channel. In particular, the method includes: determining whether a power generation operation of the fuel cell stack is resumed; when the power generation operation of the fuel cell stack is resumed, controlling a voltage source to apply a voltage to the gas adsorption unit; and supplying air to the fuel cell stack through the air channel in a state in which the voltage is applied to the gas adsorption unit.

An apparatus monitors the state of charge (SOC) of a flow battery system. The monitoring method include determining SOCs of at least two pairs of different monitoring positions. A pair of monitoring position may be located inside of an anode electrolyte storage tank (2) and inside of a cathode electrolyte storage tank (3), or inside of an anode electrolyte outlet pipeline (6) of a stack and inside of a cathode electrolyte outlet pipeline (7) of the stack, or inside of an anode electrolyte inlet pipeline (8) of the stack and inside of a cathode electrolyte inlet pipeline (9) of the stack. The SOC.sub.sum of the flow battery system is acquired according to the SOCs corresponding to different pair of monitoring positions, respectively. The method ensures acquiring an SOC monitoring result timely and accurately.

An air supply system for a fuel cell includes: a fuel cell stack in which multiple unit cells are stacked and that generates electricity through chemical reactions, an air channel to supply incoming air containing oxygen to the fuel cell stack and to transfer air discharged from the fuel cell stack to the outside of the air supply system, and a gas adsorption unit that is disposed on the air channel, positioned near an outlet of the fuel cell stack, and adsorbs oxygen contained in the air introduced into the air channel.

The present disclosure makes it possible to store data on the cause of an output shortage in a memory while reducing the capacity of the memory for storing data on an output shortage. A fuel cell system of the present disclosure comprises: a drive motor for driving a vehicle; a plurality of power sources that include a fuel cell and a secondary battery; a memory that stores data on a failure of output of the drive motor; and a controller that controls writing of the data on the failure into the memory. When an actual output value of the drive motor is smaller than a reference value decided by an output request value, the controller stores in the memory data on operating state of one of power sources, with an actual output value smaller than a power source output request value.

This disclosure relates to module level redundancy for fuel cell systems. A monitoring component monitors a set of operational parameters for a fuel cell group. The fuel cell group includes a set of fuel cell units, each having a set of fuel cell stacks. The fuel cell stacks include a set of gas powered fuel cells that convert air and fuel into electricity using a chemical reaction. The monitoring component determines that the set of operational parameters do not satisfy a set of operational criteria, and, in response, a load balancing component adjusts the electrical output capacity of the set of fuel cell units included in the fuel cell group.

A redox flow battery system including a cell and a monitor cell to which a same electrolyte solution is supplied; a current measuring unit that measures a current that is input to and output from the cell; a voltage measuring unit that measures an open circuit voltage of the monitor cell; and a computing unit. The computing unit includes a first processing unit, a second processing unit, and a third processing unit. The first processing unit computes an integral value obtained by integrating a current value measured by the current measuring unit, for an amount of time corresponding to a predetermined time constant. The second processing unit computes a corrected voltage value based on a measured voltage value measured by the voltage measuring unit and the integral value. And the third processing unit calculates a first state-of-charge value of the electrolyte solution from the corrected voltage value.

An output performance diagnosis apparatus for a fuel cell acquires, in a case where determination is made that a representative value of impedance of the fuel cell acquired during a trip of a vehicle traveling with a fuel cell as a power source is equal to or less than an impedance threshold, during the trip in which the impedance is acquired, a current-voltage characteristic of the fuel cell based on a change of an output voltage of the fuel cell after a period in which the output voltage of the fuel cell is maintained in a range equal to or higher than a lower limit voltage and equal to or lower than a voltage threshold higher than the lower limit voltage over a predetermined period or more, and calculates maximum output electric power of the fuel cell based on the acquired current-voltage characteristic.