Provided is an aging device for a fuel cell stack, capable of reliably detecting the generation of a negative voltage during aging while also achieving a cost reduction with reduced cell monitors. The voltage of an end cell on the reactant gas inlet side, in which the voltage is likely to become the highest, is monitored alone, so that the generation of a negative voltage in each of a plurality of individual central cells other than the end cell is estimated.

A method of controlling energy supply in a fuel cell vehicle includes storing an output current of a fuel cell as a pre-limited current when a cell voltage ratio reaches a minimum cell voltage ratio, setting a limited output current of the fuel cell as the pre-limited current when the cell voltage ratio reaches a hazard cell voltage ratio, connecting first and second high-voltage batteries to a main bus terminal in parallel when the cell voltage ratio reaches the hazard cell voltage ratio, and outputting a supplementary current from the second high-voltage battery by an insufficient amount of the output current of the fuel cell for the pre-limited current, and a system for performing the same.

A fuel cell system includes: a converter that boosts a voltage input from a fuel cell; a voltage control device that can control a voltage input from an electricity storage unit; a drive circuit that converts direct-current electricity input from the converter and the voltage control device into alternating-current electricity and outputs the converted electricity to the load; a relay that switches between a connected state in which the fuel cell and the drive circuit are connected to each other and a disconnected state in which they are disconnected from each other; and a controller that determines whether the relay is welded by different determination methods using an index current value between the relay and the fuel cell and a first index voltage value between the relay and the converter when the fuel cell system is to be stopped.

A fuel cell system includes: a fuel cell; a voltage regulator that regulates an output voltage of the fuel cell; and a controller configured to perform a refresh process of decreasing the output voltage of the fuel cell to a reduction voltage at which an oxide film formed on the cathode is reduced, by controlling the voltage regulator. The controller, before the refresh process, calculates a first amount, the first amount being an amount by which the oxide film is to be removed from the cathode. The controller determines, as the output voltage of the fuel cell, a refresh voltage that enables the first amount of the oxide film to be removed within a preset reference time. The controller operates the voltage regulator so as to cause the output voltage of the fuel cell to become the refresh voltage when the refresh process is performed.

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.

The fuel cell system of the present disclosure includes: a fuel cell that includes a membrane electrode assembly including a proton conducting ceramic electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power through an electrochemical reaction using a fuel gas and an oxidant gas; a power source that applies a voltage to the fuel cell; and a controller. In a shutdown process, the controller controls the power source to apply the voltage to the fuel cell such that a terminal voltage of the fuel cell is equal to or higher than an open circuit voltage of the fuel cell.

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 cell voltage control unit is provided on a lower surface of a stack body of a fuel cell stack. The cell voltage control unit is connected to cell voltage terminals for monitoring cell voltage. A protection member is provided on a second end plate where the cell voltage control unit is provided. The protection member has protrusions protruding from both sides of the protection member in a horizontal direction, and a body portion having a vertically elongated shape so as to extend to a front face of the cell voltage control unit.

Proposed is a fuel cell power control system. A fuel cell generates electric power. A load unit is electrically connected to the fuel cell. A DC/DC converter is disposed between the fuel cell and the load unit to convert the electric power between a low side of the DC/DC converter electrically connected to the fuel cell and a high side of the DC/DC converter electrically connected to the load unit. A battery is electrically connected to the high side of the DC/DC converter to be parallel to the load unit. A controller monitors a voltage of the load unit, the battery, or the high side of the DC/DC converter, and controls the electric power input to the load unit or output from the load unit in accordance with the monitored voltage.