A power supply system comprising: power storage device (1); a fuel cell (2) connecting to the power storage device (1); an auxiliary machine (4) of the fuel cell, the auxiliary machine (4) operating in a range corresponding to a voltage across the fuel cell (2); a voltage converter (3) inserted along a first line between the fuel cell (2) and the power storage device (1). The power supply system further comprising an auxiliary machine power supplying device (5) inserted between the voltage converter (3) and the power storage device (1), the power supply device for the auxiliary machine (5) being configured to supply power from at least one of the fuel cell (2) and the power storage device (1) to the auxiliary machine (4); and a switch (6) inserted along a second line different from the first line between the fuel cell (2) and the auxiliary machine (4), the switch (6) being configured to supply power to the auxiliary machine (4).

A system includes a redox flow battery system that includes an anolyte, a catholyte, a first half-cell having a first electrode in contact with the anolyte, a second half-cell having a second electrode in contact with the catholyte, and a first separator separating the first half-cell from the second half-cell. The system also includes a balance arrangement that includes a balance electrolyte having vanadium ions in solution, a third half-cell having a third electrode in contact with the anolyte or the catholyte, a fourth half-cell having a fourth electrode in contact with the balance electrolyte, and a reductant in the balance electrolyte or introducible to the balance electrolyte for reducing dioxovanadium ions.

Disclosed are an apparatus and method for estimating a state-of-charge of a zinc flow battery by measuring a concentration of zinc ions contained in an electrolyte through an open-circuit voltage (OCV). The apparatus according to embodiments of the present invention can estimate effectively the state-of-charge of the zinc flow battery from the concentration of zinc ions measured through the OCV of the working electrode with respect to the reference electrode when the measuring electrodes are installed in the cathode electrolyte tank or the anode electrolyte tank.

Methods and apparatus for detecting electrical short circuits in fuel cell stacks are provided. The methods involve supplying a reactant and an inert gas to a fuel cell stack and measuring the open circuit voltage of fuel cell assemblies in the fuel cell stack. The sensitivity of the methods can be adjusted to detect an electrical short circuit having a resistance at or below a particular threshold short-circuit resistance value, by using a suitable reactant concentration in the method. The methods can include determining a set-point reactant concentration that can be used to detect an electrical short circuit having a resistance at or below a particular threshold short-circuit resistance value.

A system for measuring a stack cell voltage of a fuel cell according to the present invention comprises: a stack voltage measuring unit which measures a stack voltage of a stack cell battery for each channel; a correction variable calculating unit which calculates a correction variable by using the stack voltage value measured by the stack voltage measuring unit; and a stack voltage value correcting unit which corrects the stack voltage measured by the stack voltage measuring unit on driving by using the correction variable.

A fuel cell system includes a plurality of fuel cells. Each of the fuel cells may include a current bypass device that is configured to flow a current responsive to an anode potential exceeding a cathode potential to prevent carbon corrosion within the fuel cell.

A controller-executed method for conditioning a membrane electrode assembly (MEA) in a fuel cell for use in a fuel cell stack includes humidifying a fuel inlet to the stack to a threshold relative humidity level, and maintaining a current density and cell voltage of the fuel cell at a calibrated current density level and hold voltage level, respectively, via the controller in at least one voltage recovery stage. The recovery stage has a predetermined voltage recovery duration. The method includes measuring the cell voltage after completing the predetermined voltage recovery duration, and executing a control action with respect to the fuel cell or fuel cell stack responsive to the measured cell voltage exceeding a target voltage, including recording a diagnostic code via the controller indicative of successful conditioning of the MEA. A fuel cell system includes the fuel cell stack and controller.

A system includes a redox flow battery system that includes an anolyte having chromium ions in solution, a catholyte having iron ions in solution, a first half-cell having a first electrode in contact with the anolyte, a second half-cell having a second electrode in contact with the catholyte, and a first separator separating the first half-cell from the second half-cell. The system also includes a balance arrangement that includes a balance electrolyte having vanadium ions in solution, a third half-cell having a third electrode in contact with the anolyte or the catholyte, a fourth half-cell having a fourth electrode in contact with the balance electrolyte, and a reductant in the balance electrolyte or introducible to the balance electrolyte for reducing dioxovanadium ions.

This specification describes a system and method for controlling the voltage produced by a fuel cell. The system involves providing a bypass line between an air exhaust from the fuel cell and an air inlet of the fuel cell. At least one controllable device is configured to allow the flow rate through the bypass line to be altered. A controller is provided to control the controllable device. The method involves varying the rate of recirculation of air exhaust to air inlet so as to provide a desired change in fuel cell voltage.

A method for estimating power consumption of a motor includes steps of: determining an error voltage for a terminal voltage of each of multiple phases of the motor, the terminal voltage being supplied from an inverter to the motor; generating a compensation terminal voltage for each of the multiple phases of the motor by applying the error voltage to a prediction value of the terminal voltage that is derived in a preset manner during operation of the motor; and calculating power consumption of the motor by using the compensation terminal voltage and a current value obtained by detecting a current that flows in each of the multiple phases of the motor.