A method of measuring impedance of a fuel cell stack in a vehicle during driving of the vehicle includes: determining whether an impedance measurement of the fuel cell stack is requested during driving of the vehicle driven by power of the fuel cell stack; turning off a first relay connected between the fuel cell stack and a battery charged by the fuel cell stack when the impedance measurement of the fuel cell stack is requested; connecting a stack load to the fuel cell stack via a second relay and supplying air to the fuel cell stack; and measuring the impedance of the fuel cell stack.

A current control system includes a boost converter, and a converter controller that selectively performs control in a continuous mode using a calculated duty ratio for the continuous mode and control in a discontinuous mode using a calculated duty ratio for the discontinuous mode. The converter controller performs, at least in calculation of the duty ratio for the continuous mode, rising speed adjustment processing for adjusting a parameter used for the calculation of the duty ratio so that a rising amount of the duty ratio is restricted relative to the duty ratio used in a last cycle in accordance with a predetermined limit value, so as to restrict a rising speed of the duty ratio for the continuous mode more than a rising speed of the duty ratio for the discontinuous mode.

A fuel cell system includes: a converter that boosts a voltage input from a fuel cell; a voltage control device that can control a voltage input from an electricity storage unit; a drive circuit that converts direct-current electricity input from the converter and the voltage control device into alternating-current electricity and outputs the converted electricity to the load; a relay that switches between a connected state in which the fuel cell and the drive circuit are connected to each other and a disconnected state in which they are disconnected from each other; and a controller that determines whether the relay is welded by different determination methods using an index current value between the relay and the fuel cell and a first index voltage value between the relay and the converter when the fuel cell system is to be stopped.

A DC voltage distribution arrangement and method of controlling a DC voltage distribution system, the DC voltage distribution system including a DC voltage bus, a fuel cell electrically connected to the DC voltage bus, an energy storage and an energy storage converter, wherein the input of the energy storage converter is connected to the energy storage and the output of the energy storage converter is connected to the DC bus. The method comprises providing a DC voltage reference for the energy storage converter, the energy storage converter controlling the voltage of the DC voltage bus by providing power from the energy storage or to the energy storage, detecting power flow of the energy storage converter, and changing the DC voltage reference on the basis of the detected power flow to change the power taken from the fuel cell.

According to one embodiment of the present disclosure, a redox flow battery is provided comprising an ionically conductive separator, a working side flowing electrolyte, a working electrode in ionic contact with the working side of the ionically conductive separator and the working side flowing electrolyte, a counter electrode, and an auxiliary electrode peripherally circumscribed by the working electrode in a common layer of the flow battery. The auxiliary electrode is in ionic contact with the working electrode, an electrically insulating peripheral gap separates the auxiliary electrode from the working electrode. A working electrode terminal is conductively coupled to the working electrode, an auxiliary electrode terminal is conductively coupled to the auxiliary electrode, and a counter electrode terminal is conductively coupled to the counter electrode. An auxiliary power source is configured to establish an auxiliary circuit voltage differential between the counter electrode terminal and the auxiliary electrode terminal, control an auxiliary electrode voltage such that the auxiliary electrode voltage is within an electrochemical window of the working side flowing electrolyte, and establish a voltage differential between the working electrode terminal and the auxiliary electrode terminal. A method of operation of the redox flow battery is further provided

The present disclosure provides a method of shortening an aging period of a polymer electrolyte fuel cell immediately after production to increase shipping inspection speed and production speed of the polymer electrolyte fuel cell. The present disclosure relates to an aging method of a fuel cell which comprises a membrane electrode assembly comprising a fuel electrode, an electrolyte membrane, and an oxidant electrode, wherein the method comprises applying a potential cycle, wherein the lowest cell potential when a load is applied and OCV are alternately repeated between the fuel electrode and the oxidant electrode, and in the potential cycle, fuel gas is supplied to the fuel electrode, and oxidant gas and carbon monoxide gas are supplied to the oxidant electrode.

A process for starting a PEM fuel cell module includes blowing air through the cathode side of the module using external power. An amount hydrogen is released into the anode side of the module under a pressure greater than the pressure of the air on the cathode side, while the anode is otherwise closed. Cell voltages in the module are monitored for the appearance of a charged state sufficient to start the module. When the charged state is observed, the module is converted to a running state.

A power generation system includes a power source that is configured to communicate with at least one of a downstream load or a downstream device by changing a voltage on a power bus between the power source and the at least one of the downstream load or the downstream device, while power source provides power on the power bus to the at least one of the downstream load or the downstream device.

A fuel cell system includes: a first fuel cell; a second fuel cell having a greater maximum power output than the first fuel cell; and a controller configured to cause the first fuel cell to generate greater electric power greater than the second fuel cell when the requested power is smaller than a first threshold, cause the second fuel cell to generate greater electric power than the first fuel cell when the requested power is a second threshold, which is the first threshold or greater and smaller than a third threshold that is greater than the second threshold, is 70% of the maximum power output of the second fuel cell or grater, and is 100% of the maximum power output of the second fuel cell or smaller, and cause both the first and second fuel cells to generate electric power when the requested power is the third threshold or greater.

Disclosed are a fuel cell system and a method for controlling the same which enable performance recovery of a stack together with a high potential avoidance operation while operating the fuel cell system. The fuel cell system includes a fuel cell stack, in which a first separation plate having a first air flow path and a second separation plate having a second, different air flow path are alternately stacked with a membrane-electrode assembly interposed therebetween; and the method includes determining whether a high-potential avoidance operation is required while operating the fuel cell system including the fuel cell stack, and selectively supplying air to the air flow path of the first separation plate or the second separation plate when a high-potential avoidance operation is required, so as to easily achieve cathode performance recovery during the high-potential avoidance operation of the fuel cell system and the operation of the fuel cell system.