Systems and methods for operating an electric energy storage device are described. The systems and methods may generate a state of charge estimate that is based on negative electrode plating. An overall state of charge may be determined from the state of charge estimate that is based on negative electrode plating and a state of charge estimate that is not based on negative electrode plating.

Introduced is an fuel cell power net including a fuel cell configured to generate power through a reaction between a fuel gas and an oxidizing gas, a power storage device configured to be charged with power generated by the fuel cell or discharged to supply power, a main line configured to electrically connect the fuel cell and the power storage device to each other; a main relay disposed on the main line so as to break or make an electrical connection between the fuel cell and the power storage device, a bypass line which is branched from the main line, bypasses the main relay, and is connected to the power storage device, a bypass relay disposed on the bypass line so as to break or make an electrical connection of the bypass line, and a controller configured to control the main relay or the bypass relay such that the power stored in the storage device is supplied to the fuel cell while the power generation of the fuel cell is stopped.

An apparatus for controlling a fuel cell of an environment-friendly vehicle, a system including the same, and a method thereof are provided. The apparatus includes a storage storing information mapping an amount of additional output of a fuel cell according to air density and a current battery state of a high voltage battery depending on a drive mode and a processor that controls an amount of output of the fuel cell in response to a required amount of output of a motor, the amount of output of the fuel cell being varied according to the air density, the current battery state, and the drive mode based on the information mapping the amount of additional output.

In a fuel cell vehicle and a method of controlling the fuel cell vehicle, when a gas pressure in a high pressure tank becomes less than a first threshold pressure, the SOC of an energy storage device is increased to a margin SOC. When the gas pressure becomes a second threshold pressure which is lower than the first threshold pressure, the amount of fuel released from the high pressure tank is limited to prevent the occurrence of buckling, and limit the travel driving force by the motor to a required limit. At the time of limiting the travel driving force, electrical energy of the energy storage device is used to provide assistance in a manner that the travel driving force by the motor becomes the travel driving force of the required limit.

An apparatus and a method for controlling a fuel cell system includes a fuel cell system including a fuel cell stack, a balance of plant for operating the fuel cell stack, and a fuel cell controller configured for controlling the BOP, a first power converter located between the fuel cell stack and a first voltage battery and including a bidirectional low voltage DC/DC converter, a second power located between the fuel cell stack and a second voltage battery to include a single bidirectional DC/DC converter module, and a controller configured for operating the first power converter or the single bidirectional DC/DC converter module of the second power converter, when the fuel cell system is started or stopped, and controlling the first power converter or the second power converter to supply driving power to the BOP using electrical energy of the first voltage battery or the second voltage battery.

A fuel cell system and the method of controlling the fuel cell system improve next-time startability in the following manner. Hydrogen, air, generation water, and the like that remain inside a large-sized fuel cell system needs to be removed after finishing operation of the large-sized fuel cell system, such as a fuel cell system for generating electric power. To the present end, when an air compressor needs to be operated, one fuel cell module is selected as a power supply module, and an air compressor is operated by the power supply module. Thus, durability of a fuel cell stack is improved, and at the same time, a constant amount of generated electricity necessary to restart the large-sized fuel cell system is ensured.

A fuel cell system includes a plurality of fuel cells and a control device that controls an operation state of each fuel cell. The control device has a command receiver that acquires an output command showing a total output power which should be generated by the fuel cell system, a first determiner that determines the number of fuel cells which should be operated in the normal operation mode, and an operation state manager that determines the operation state of each fuel cell. Based on the output command, the operation state manager changes the operation state of at least one of the fuel cells which are being operated in the normal operation mode to the standby operation mode, or changes the operation state of at least one of the fuel cells which are being operated in the standby operation mode to the normal operation mode.

A fuel cell system that can improve an operating efficiency while minimizing an increase in cost for a configuration is provided. A fuel cell system (10) includes a fuel cell stack (11), an air pump (13), and an electric power control unit (15). The air pump (13) is connected to an output terminal of the fuel cell stack (11). The air pump (13) is configured to supply air as an oxidizing agent gas to the fuel cell stack (11). The electric power control unit (15) includes a first circuit unit (31) and a second circuit unit (32). The first circuit unit (31) is connected to the output terminal of the fuel cell stack (11) and is configured to perform step-up electric power conversion on an input from the fuel cell stack (11). The second circuit unit (32) is configured to perform bidirectional electric power conversion for stepping-up an input from the fuel cell stack (11) and for stepping-down an output to the air pump (13).

A fuel cell system includes: a fuel cell; a fuel cell step-up converter having an input terminal, wherein the input terminal is connected to the fuel cell; a secondary cell; a secondary cell step-up converter having an input terminal an output terminal, wherein the input terminal is connected to the secondary cell. wherein the output terminal is connected to an output terminal of the fuel cell step-up converter; and a control device configured to control at least the fuel cell step-up converter and the secondary cell step-up converter to control the fuel cell system, wherein, the control device executes interruption control when the control device executes continuity control and an output of the fuel cell system is requested to be greater than an output of the secondary cell in the continuity control, wherein the continuity control is a control to control the secondary cell step-up converter to output an input voltage from the secondary cell without stepping up the input voltage, wherein the interruption control is a control to interrupt an electrical connection between the fuel cell system and the secondary cell.

An ECU of a fuel cell vehicle determines whether the vehicle travels on an uphill road or not. When determining that the vehicle travels on the uphill road, the ECU performs at least one of a temperature reduction control for reducing the temperature of a fuel cell stack and a humidification control for increasing the water content of the fuel cell stack, by the time the vehicle reaches the uphill road.