A fuel cell system that includes a first fuel cell that generates electric power using a hydrogen-containing fuel gas; a second fuel cell that generates electric power using off-gas exhausted from the first fuel cell and containing hydrogen that has not reacted in the first fuel cell; a first control device that controls the electric power output from the first fuel cell by adjusting a current or a voltage being output from the first fuel cell; a second control device that controls the electric power output from the second fuel cell by adjusting a current or a voltage being output from the second fuel cell; and an output control device that controls at least one of the first control device or the second control device such that a total electric power being generated by the first fuel cell and the second fuel cell approaches an electric power demand.

In a control device for a power converter converting electric power of a fuel cell stack, the power converter includes first and second reactors, a first switching element connected to the first reactor, and a second switching element connected to the second reactor. The second reactor is located closer to a cooling water discharge manifold than the first reactor. The control device configured to: set first and second duty cycles of the first and second switching element; and execute limit control in which, by controlling the setting of the first and second duty cycles, a second amount of heat generated by the second reactor due to a second current is limited to a value smaller than a first amount of heat generated by the first reactor due to a first current within a period of at least multiple ON-OFF cycles of the first and second switching elements.

A fuel cell system includes a fuel cell, an accumulator configured to store a fuel gas, a gas remaining quantity acquisition unit configured to obtain a remaining quantity of the fuel gas stored in the accumulator, and a power generation control unit. When the remaining quantity of the fuel gas stored in the accumulator is decreased to a threshold value, the power generation control unit performs switching from humid power generation control to dry power generation control.

A fuel cell reversal event is diagnosed by integrating current density via a controller in response to determine an accumulated charge density. The controller executes a control action when the accumulated charge density exceeds a threshold, including recording a diagnostic code indicative of event severity. The control action may include continuing stack operation at reduced power capability when the accumulated charge density exceeds a first threshold and shutting off the stack when the accumulated charge density exceeds a higher second threshold. The event may be detected by calculating a voltage difference between an average and a minimum cell voltage, and then determining if the difference exceeds a voltage difference threshold. The charge density thresholds may be adjusted based on age, state of health, and/or temperature of the fuel cell or stack. A fuel cell system includes the stack and controller.

The data recording apparatus includes a model storage configured to store a model generated by use of sample data indicating a measurement value of a sample and a degree of deterioration of the sample at the time when the measurement value is obtained, and a controller configured to acquire target data indicating a measurement value of a target and a degree of deterioration of the target at the time when the measurement value is obtained. The model storage stores a first model generated by use of the sample data relevant to the degree of deterioration of the sample belonging to a first range, and a second model generated by use of the sample data relevant to the degree of deterioration of the sample belonging to a second range partially overlapping with the first range. The controller generates first data indicating change in a first abnormality of the target in accordance with the degree of deterioration in the first range, by use of the target data and the first model, and generates second data indicating change in a second abnormality of the target in accordance with the degree of deterioration in the second range, by use of the target data and the second model.

A fuel cell vehicle is mounted with a fuel cell system including a fuel cell stack and a battery. The fuel cell vehicle controls operation of the fuel cell system with an ECU, to perform standby power generation from activation to when travel is allowed and to perform power generation during operation of the fuel cell vehicle after travel has been allowed. In an activation method, the power generation current is increased in accordance with a low-temperature efficiency rate during the power generation during operation, the battery is charged and the power generation current is increased in accordance with a standby current increase rate that is lower than the low-temperature efficiency rate during the standby power generation.

The present disclosure relates to a control method for a fuel cell. The control method includes: collecting, by a controller, state information of a fuel cell (FC) stack; determining, by the controller, a degradation state of the FC stack from the collected state information of the FC stack; correcting, by the controller, a basic threshold output corresponding to a present driving state of a vehicle on the basis of information of the determined degradation state of the FC stack; comparing, by the controller, a post-correction threshold output that is obtained by correcting the basic threshold output and a motor demand output, and determining, by the controller, stopping or restarting of a fuel cell; and controlling, by the controller, such that the determined stopping or restarting state of the fuel cell is achieved.

Methods and systems are provided for iron preformation in a redox flow battery. In one example, a method may include, in a first condition, discharging and then charging the redox flow battery, and in a second condition, charging the redox flow battery including preforming iron metal at a negative electrode of the redox flow battery, and thereafter entering an idle mode of the redox flow battery including adjusting one or more electrolyte conditions. In some examples, each of preforming the iron metal and adjusting the one or more electrolyte conditions may increase a battery charge capacity to greater than a threshold battery charge capacity.

First, a reaction gas is supplied to a fuel cell stack including a laminate of solid polymer electrolyte fuel cells and power generation is performed so that a temperature of the fuel cell stack reaches 65 C. or higher (heating power generation step). Next, the reaction gas is supplied to the fuel cell stack and the power generation is performed under a condition in which relative humidity is 100% or more (cleaning power generation step). Cooling water of room temperature may be supplied to the fuel cell stack from the outside before the cleaning power generation step is performed after the heating power generation step is completed, or after the cleaning power generation step is completed (quenching step).

A control method for a fuel cell system that includes a solid oxide fuel cell configured to generate power upon receipt of supply of an anode gas and a cathode gas includes an anode protection execution determination process of performing execution determination of an anode protection process of applying a predetermined protection current to the fuel cell in order to restrain catalyst oxidation in an anode of the fuel cell. In the anode protection execution determination process, an internal impedance of the fuel cell at an anode response frequency at which an anode reaction resistance of the fuel cell is detectable is acquired, and based on the internal impedance at the anode response frequency, whether the anode protection process is to be executed or not is determined.