The invention relates to a fuel cell system (100, 1) comprising: at least one fuel cell (200) which has a cathode (230) with a cathode chamber and has an anode chamber of an anode (210), which anode chamber is separated from the cathode chamber by a membrane, wherein the cathode chamber is connected to a cathode gas source via at least one first fluid connection (240) and the anode chamber is connected to an anode gas source via at least one second fluid connection; and comprising a first electrical connection (3) to a DC/DC converter (450) that electrically connects the anode (210) and the cathode (230) to an energy system (400), wherein in a shut-down phase of the fuel cell system (100, 1), residual energy present in the fuel cell (200) can be discharged. According to the invention, the anode (210) is connected to the energy system (400) and/or the cathode (230) via at least one second electrical connection (2), wherein the second electrical connection (2) is a bypass connection to the DC/DC converter (450) and/or the second electrical connection (2) is a bypass connection parallel to the fuel cell (200), wherein at least the residual energy can be discharged via the second electrical connection (2), and the second electrical connection (2) comprises a resistor (6).

A flow battery system has an electrolyte storage tank, a flow battery, and a box-type flow battery system. A circular pipe I and a circular pipe II are provided in the electrolyte storage tank; the circular pipe II is communicated with an electrolyte return opening; the circular pipe I is communicated with an electrolyte delivery outlet; the annular perimeter of the circular pipe I is not equal to the annular perimeter of the circular pipe II. The multi-layer circular pipe structure in the storage tank reduces the flowing dead zone of electrolyte in the storage tank. Moreover, The reduction in the longitudinal distance between the electrolyte delivery outlet and the electrolyte return opening also reduced the problem of SOC lag so that the SOC monitoring accuracy of the flow battery is improved.

A fuel cell system includes a removal treatment execution unit configured to execute an oxide layer removal treatment that removes an oxide layer generated on a catalyst of a fuel cell. The removal treatment execution unit is configured to execute the oxide layer removal treatment by adjusting a voltage of the fuel cell to be within a predetermined second voltage range lower than a predetermined first voltage range that is lower than an open-circuit voltage, when an operation of the fuel cell system shifts from a first operation, where a current value of the fuel cell is zero and the flow rate is controlled to maintain the voltage of the fuel cell within the first voltage range, to a second operation, where the current value is larger than zero and the flow rate is controlled in response to an output request to the fuel cell.

During power reduction transitions of a fuel cell power plant, the excess electric energy generated by consumption of reactants is extracted, during one or more periods of time, by a voltage limiting device control (200) in response to a controller (185) as i) energy dissipated in a resistive auxiliary load or ii) as energy applied to an energy storage system (201) (a battery), in boost and buck embodiments. The controller operates the voltage limiting device control in response to the positive time derivative of the voltage of one or more of the fuel cells exceeding a predetermined limiting value.

A supply device for the electrical supply of at least one consumer has a primary current system in which there is a fuel cell device, a secondary current system in which there is a battery which has an operating voltage range limited at the top by a maximum voltage and at the bottom by a minimum voltage and which has an operating current strength range for supplying current to the at least one consumer, and a frost-starting element, which is provided in the primary current system and is designed to bring about heating of the fuel cell device. An open-circuit voltage of the fuel cell device corresponds at most to the maximum voltage of the battery.

A restarting system, a controller, and a restarting method for a fuel cell vehicle are provided. The restarting system includes a consumption resistor connected in parallel to a high voltage line that connects between a fuel cell and a high voltage battery and a relay that adjusts the connection between the consumption resistor and the high voltage line. A controller operates the relay and when a shutdown request signal of the vehicle is input, charges the high voltage battery with residual generated power of the fuel cell or connects the relay to the consumption resistor to consume the residual generated power as the consumption resistance. When a starting request signal of the vehicle is input, the controller is reset when an output voltage of the fuel cell is reduced to be equal to or less than a required voltage and then output a starting permission signal of the vehicle.

A redox flow battery includes a redox flow cell, a supply/storage system external of the redox flow cell, and a controller. The supply/storage system includes first and second electrolytes for circulation through the redox flow cell. The first electrolyte is a liquid electrolyte having electrochemically active species with multiple, reversible oxidation states. The electrochemically active species can form a solid precipitate blockage in the redox flow cell. The controller is configured to identify whether there is the solid precipitate blockage in the redox flow cell and, if so, initiate a regeneration mode that reduces the oxidation state of the electrochemically active species in the liquid electrolyte to dissolve, in situ, the solid precipitate blockage.

A process for starting a PEM fuel cell module includes blowing air through the cathode side of the module using external power. An amount hydrogen is released into the anode side of the module under a pressure greater than the pressure of the air on the cathode side, while the anode is otherwise closed. Cell voltages in the module are monitored for the appearance of a charged state sufficient to start the module. When the charged state is observed, the module is converted to a running state.

A fuel cell system includes a controller configured to execute refreshing control for removing an oxide film on a catalyst during an operation of a fuel cell, and an impedance measurer configured to measure an impedance of the fuel cell during the operation of the fuel cell. The impedance measurer executes a calculation process for calculating the impedance by using measurement values of a current and a voltage of the fuel cell in a predetermined measurement time, and outputs a substitute value prepared in advance as the impedance when the start of the refreshing control during the measurement time is detected.

An operation control system and method of a fuel cell vehicle are provided. The system includes a fuel cell, an air supply device operated by a motor, to supply air to the fuel cell and a sensing unit that senses an abnormal operation of the air supply device. A calculation unit calculates a lower-limit voltage of the air supply device required for normal operation of the air supply device when the sensing unit senses abnormal operation of the air supply device. A controller then adjusts a voltage supplied to the air supply device based on the calculated lower-limit voltage.