A fuel cell system includes a fuel cell a temperature acquisition unit that acquires a temperature of the fuel cell, a cell unit voltage sensor that detects a voltage of each of fuel cell units, and a controller that controls the fuel cell system. The controller restricts an output current of the fuel cell when the voltage of the individual fuel cell unit becomes equal to or lower than a predetermined value in a warm-up operation, execute the warm-up operation when the temperature of the fuel cell is equal to or lower than a predetermined temperature, after the fuel cell system receives a start-up request, and stop an operation of the fuel cell system when a stop condition including that the voltage of the fuel cell unit is continuously equal to or lower than a predetermined voltage value for a predetermined time is satisfied after start of the warm-up operation.

A controller stops flow of posolyte through a positive electrode chamber of a flow cell to trap the posolyte within the positive electrode chamber and hydraulically isolate the flow cell without stopping flow of negolyte through a negative electrode chamber of the flow cell, discharges the flow cell until hydrogen gas is evolved at a reactive surface of the positive electrode chamber while the posolyte is trapped within the positive electrode chamber, and subsequently discontinues the discharge and restarts the flow of the posolyte through the positive electrode chamber.

The control method for a flow battery includes acquiring a current electrolyte capacity decay rate of the flow battery; comparing the current electrolyte capacity decay rate with a first preset decay rate and a second preset decay rate; when the current electrolyte capacity decay rate is greater than the first preset decay rate and less than the second preset decay rate, adjusting a liquid level of positive electrolyte and a liquid level of negative electrolyte, such that a difference between these two liquid levels is less than a preset value, a ratio of the total amount of vanadium in the positive electrolyte to the total amount of vanadium in the negative electrolyte remains in a first preset ratio range, or a ratio of a vanadium ion concentration in the positive electrolyte to a vanadium ion concentration in the negative electrolyte remains in a second preset ratio range.

The present invention comprises a method and system for improving the energy efficiency of a vanadium flow battery, VFB. This is achieved by simultaneously reconditioning the VFB through in-situ activation of the electrodes.

A fuel cell based power generator includes a fuel cell element, an ambient air path configured to receive ambient air and provide the ambient air across a cathode side of the fuel cell element, receive water from the fuel cell element and provide wet air to the water exchanger element, and a fuel cell cooling mechanism associated with the fuel cell element, separate from the ambient air path and configured to cool the fuel cell element.

Power is generated efficiently using fuel. A power generation unit includes a power generation module that generates power using fuel, a supply unit that supplies fuel to the power generation module, a power converter that converts DC power supplied by the power generation module into AC power, and a controller that controls the supply unit and the power converter. The controller controls the supply unit or the power converter so that the output power supplied to a load with fluctuating power consumption becomes greater than the power consumption of the load by a predetermined margin.

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.

A fuel cell based power generator includes a fuel cell element, an ambient air path configured to receive ambient air and provide the ambient air across a cathode side of the fuel cell element, receive water from the fuel cell element and provide wet air to the water exchanger element, and a fuel cell cooling mechanism associated with the fuel cell element, separate from the ambient air path and configured to cool the fuel cell element.

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.

In accordance with the principles of the present invention, a system and method for the management of the power applied to electrolytic cell is provided. The power management consists a constant current regulation, H-bridge control by pulse width modulation (PWM), and dimming control of the applied current to the electrolytic cell. The constant current regulation is an analog control that maintains the applied current at a user-defined current setpoint. The time scale of constant current regulation ranges from tenth of microseconds to milliseconds. The PWM control of the H-bridge allows for the instant adjustment of the electrolytic production output by turning the cell on and off; the time scale of the PWM control ranges from tenths of milliseconds to seconds. The dimming control allows the change of the applied constant current; the time scale of the dimming control ranges from milliseconds to hours and longer.