An energy storage system includes a vanadium redox battery that interfaces with a control system to optimize performance and efficiency. The control system calculates optimal pump speeds, electrolyte temperature ranges, and charge and discharge rates. The control system instructs the vanadium redox battery to operate in accordance with the prescribed parameters. The control system further calculates optimal temperature ranges and charge and discharge rates for the vanadium redox battery.

A fuel cell system that includes a fuel cell that generates electricity through an electrochemical reaction between a fuel gas and an oxidant gas, and a control portion that determines whether there is leakage of the fuel gas. The control portion has start means for starting the fuel cell by raising the voltage of the fuel cell from a starting voltage to an operation voltage that is lower than an open-circuit voltage, and leakage determination means for determining whether there is leakage of the fuel gas before the voltage of the fuel cell reaches the operation voltage when the fuel cell is started.

A method conditions a fuel cell stack of a fuel cell system during a usage operation of the fuel cell system. The method determines that a conditioning of the fuel cell stack is to be carried out for increasing an electrical power provided by the fuel cell stack during usage operation. In addition, the method adjusts at least one operating parameter of the fuel cell system in order to increase a current flow through the fuel cell stack for conditioning the fuel cell stack during usage operation.

Provided are a recovery control system of a fuel cell and a method thereof. The recovery control system includes the fuel cell, a hydrogen supplier configured to supply hydrogen to the fuel cell, an air supplier configured to supply air to the fuel cell, an abnormality sensing unit configured to calculate a difference between a reference cell voltage predetermined depending on an output current of the fuel cell and a measured cell voltage of unit cells and to sense abnormality of air supply to a fuel cell stack based on the calculated difference between the reference cell voltage and the measured cell voltage or change in the difference, and a recovery controller configured to control the air supplier so as to increase a flow rate of air supplied to the fuel cell stack based on the change in the difference, when the abnormality sensing unit senses abnormality of air supply.

A fuel cell system supplies anode gas and cathode gas to a fuel cell and causes the fuel cell to generate electric power in accordance with a load. The fuel cell system includes a container reserved impurities discharged from the fuel cell. The fuel cell system includes a pressure control unit that makes a pressure of the anode gas higher when a current of the fuel cell is high than when the current of the fuel cell is low. The fuel cell system includes an estimation unit that varies the current of the fuel cell, and estimates a current-voltage characteristic of the fuel cell on the basis of a current value and a voltage value obtained when the current of the fuel cell has been varied. The fuel cell system includes a restriction unit that, while the estimation unit is estimating the current-voltage characteristic, restricts a reduction in the pressure of the anode gas.

A power supply apparatus, a power supply system, and a power supply method increase the power generation efficiency of the system overall in a system that includes a plurality of power source units. A power supply apparatus operates distributed power sources in parallel, the distributed power sources including power source units, and supplies output power from the distributed power sources to a load. The power supply apparatus includes a controller that controls each power source unit so that output power from whichever of the power source units has higher power generation efficiency is prioritized to increase.

A fuel cell system is disclosed, which includes an anode recirculation loop comprising a fuel cell stack for generating power, a flowmeter for measuring a fuel flow rate of a fuel provided into the anode recirculation loop, a current measuring device for measuring a current drawn from the fuel cell stack, a recycle ratio measuring device for measuring a recycle ratio in the anode recirculation loop, and a processor for estimating a fuel utilization of the fuel cell stack based on the measured fuel flow rate, the measured current and the measured recycle ratio. Methods for operating the fuel cell system are also disclosed.

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.

A fuel cell system includes a fuel cell stack configured to include a cathode and an anode, an air supplier configured to supply air to the cathode, and an air intake pipe configured to connect an outlet of the air supplier and an inlet of the cathode to each other and having an opening adjustable valve provided thereto. A controller is configured to adjust an opening of the valve according to a supplied amount of air to control a flow rate of air supplied to the cathode. Thereby, the fuel cell stack is prevented from drying-out, and durability of a fuel cell is improved.

A constant voltage control method for a fuel cell vehicle includes: determining whether vehicle state information satisfies a cold start condition when the fuel cell vehicle is started; starting constant voltage control on a fuel cell when the vehicle state information satisfies the cold start condition; comparing an RPM of an air blower for supplying air to the fuel cell with a predetermined stop control condition; and terminating the constant voltage control on the fuel cell when the RPM of the air blower satisfies the predetermined control-stopping condition.