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.

A fuel cell system includes a fuel cell stack made by stacking a plurality of cells and configured to generate power by being supplied with fuel gas and oxidation gas, a high-voltage battery configured to supplement the power generated by the fuel cell stack while being charged with the power generated by the fuel cell stack or being discharged, a converter provided between the fuel cell stack and the high-voltage battery and configured to change an output voltage or an output current of the fuel cell stack, a power control unit configured to control the fuel cell stack to generate power when the fuel cell stack is requested to be diagnosed, the power control unit being configured to adjust the output current of the fuel cell stack to a predetermined current, and a voltage sensing unit configured to sense a voltage of the fuel cell stack or voltages of the plurality of cells included in the fuel cell stack in the state in which the output current of the fuel cell stack is the predetermined current.

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.

A vehicle includes a fuel cell, an inlet valve, a purge valve, and a controller. The fuel cell has an anode side configured to receive hydrogen. The inlet valve is configured to open to deliver the hydrogen to the anode side. The purge valve is configured to open to purge water and nitrogen from the anode side. The controller is programmed to, operate the inlet valve to inject hydrogen into the anode side via opening the inlet valve followed by closing the inlet valve. The controller is further programmed to, in response to a concentration of the hydrogen in the anode side being less than threshold, open the purge valve to purge water and nitrogen from the anode side.

Disclosed are a control system for a fuel cell including a fuel cell configured to receive a fuel gas and an oxidation gas and generate electric power, a current controller configured to control an output current output from the fuel cell, based on a demanded current of the fuel cell, while maintaining an output voltage output from the fuel cell at a preset voltage or more, and a restriction controller configured to estimate an output current at the preset voltage as a maximum current when the output voltage of the fuel cell drops to become equal to or smaller than the preset voltage, and restrict the output current of the fuel cell to not more than a first restriction current set based on the estimated maximum current, and a control method for a fuel cell.

Systems, methods, and devices of the various embodiments provide a hardware and software architecture enabling electrochemical impedance spectroscopy (“EIS”) to be performed on multiple electrochemical devices, such as fuel cells, at the same time without human interaction with the electrochemical devices and to use EIS to dynamically monitor the performance of a fuel cell system. Embodiment methods may include determining an impedance of a set of fuel cells using electrochemical impedance spectroscopy, determining an ohmic polarization of the set of fuel cells from the impedance, determining a concentration polarization of the set of fuel cells from the impedance, comparing the ohmic polarization of the set of fuel cells to a first threshold, comparing the concentration polarization of the set of fuel cells to a second threshold, and initiating a corrective action when the ohmic polarization is above the first threshold or when the concentration polarization is below the second threshold.

A fuel cell system includes a fuel feeder that supplies fuel, a fuel cell stack that generates power through an electrochemical reaction using air and a hydrogen-containing gas generated from the fuel, a first temperature sensor that senses the temperature of the fuel cell stack, and a controller. The fuel cell stack has a membrane electrode assembly including an electrolyte membrane through which protons can pass, a cathode on one side of the electrolyte membrane, and an anode on the other side of the electrolyte membrane. The controller defines an upper limit of current output from the fuel cell stack on the basis of the temperature of the fuel cell stack, the supply of the fuel, and the hydrogen consumption of the fuel cell stack associated with internal leakage current and keeps the current output from the fuel cell stack at or below the upper limit.

A system and method for diagnosing a fuel cell includes one or more fuel cell modules each including a fuel cell stack to output power through a first converter and a battery connected to the fuel cell stack through a second converter; and a controller configured to determine whether diagnosis of the fuel cell stack included in the one or more fuel cell modules is required, and to control the one or more fuel cell module to simultaneously or sequentially diagnose the fuel cell stack determined to require diagnosis based on an output demand power of the one or more fuel cell modules.

A system includes a fuel cell stack (FCS) and a controller. The controller adjusts a stack current of the FCS to a desired amount to cause the FCS to provide a power commensurate with a power request. The controller employs a stack power model of the FCS in adjusting the stack current.

A fuel cell system has a fuel cell stack including a plurality of fuel cells and an anode injector system, and a controller programmed. The controller, responsive to an amplitude of cyclic changes in voltage of at least some of the fuel cells exceeding a threshold, a frequency of the cyclic changes being within a predetermined range of a frequency associated with the anode injector system, and the voltage being less than a predetermined value, disables the fuel cell stack.