A fuel cell system is configured to generate power by supplying anode gas and cathode gas to a fuel cell. The fuel cell system includes a load connected to the fuel cell and an IV estimation unit configured to change an output current of the fuel cell with a predetermined width by adjusting power supplied to the load during the warm-up of the fuel cell. The fuel cell system is configured to estimate an IV characteristic of the fuel cell on the basis of at least two sets of an output current value and an output voltage value detected while the output current is changed. The fuel cell system includes an IV estimation stop unit configured to stop the execution of the IV estimation on the basis of an output of the fuel cell during the execution of the IV estimation.

A water removing system and method of a fuel cell vehicle using impedance are provided. The system measures measure the low frequency impedance of a fuel cell stack when a fuel cell system is stopped in a low temperature condition, and adjusts the air supply amount and supply time for removing the water supercharged into the fuel cell stack using the measured low frequency impedance. Thus, air is prevented from being unnecessarily supercharged into the fuel cell stack and at the same time, the water remaining in the fuel cell stack is removed.

A method for accurately measuring the impedance of the fuel cell stack in the vehicle during operation of the vehicle includes determining whether measuring the impedance of the fuel cell stack is requested during driving of the vehicle driven by using a power of a fuel cell stack, switching a DC-DC converter connecting the fuel cell stack and a battery to each other to a buck mode when measuring the impedance is requested, thereby blocking output current of the fuel cell stack from flowing to the battery through the DC-DC converter, determining a first current value of the fuel cell stack for measuring the impedance, controlling a resistance value of a COD variable resistor consuming the output current of the fuel cell stack according to the first current value, and measuring the impedance of the fuel cell stack while the output current of the fuel cell stack is maintained at the first current value.

A device intended to generate electricity includes a planar fuel cell having: cells each provided with an anode and a cathode associated with a membrane, and a first face and a second face opposite to the first face, the first face being arranged on the side with the anodes of the fuel cell and the second face being arranged on the side with the cathodes of the fuel cell. Furthermore, this device includes a system configured to generate a first air flow intended to cooperate thermally with the first face, and configured to generate a second air flow intended to cooperate with the second face to ensure the supply of oxidizer to the cathodes of the fuel cell.

A fuel cell system, comprising: a fuel cell stack including a stacked body provided by stacking a plurality of cells in a stacking direction; a compressor configured to feed a purge gas to a cathode of the fuel cell stack; a controller configured to control the compressor, such as to perform stop-time purging that purges the cathode of the fuel cell stack when operation of the fuel cell system is stopped; a first temperature gauge configured to measure a first temperature value that reflects temperature of a cell placed near a center in the stacking direction among the plurality of cells constituting the stacked body and to input the measured first temperature value into the controller; and a second temperature gauge configured to measure a second temperature value that reflects temperature of a cell placed near an end in the stacking direction among the plurality of cells constituting the stacked body and to input the measured second temperature value into the controller, wherein the controller is configured to suspend the stop-time purging when the first temperature value is equal to or higher than a first reference temperature and the second temperature value is lower than a second reference temperature.

Methods are disclosed for starting up a fuel cell system from starting temperatures below 0 C. The methods apply to systems comprising a solid polymer electrolyte fuel cell stack whose cathodes comprise an oxygen reduction reaction (ORR) catalyst and whose anodes comprise both a hydrogen oxidation reaction (HOR) catalyst and an oxidation evolution reaction (OER) catalyst. In the methods, from the beginning of starting up until the fuel cell temperature reaches 0 C., the fuel cell stack current is kept sufficiently low such that the current density drawn does not exceed the stack's capability for the oxidation evolution and the oxygen reduction reactions to occur at the anode and cathode respectively (i.e. current density drawn is less than the stack's maximum OER/ORR current density).

An energy conversion arrangement configured to convert chemical energy into electrical energy. The energy conversion arrangement comprises plural cell groups 30, 32, 34, 36, each cell group being configured to convert chemical energy into electrical energy. The energy conversion arrangement also comprises at least one measurement arrangement 38, 40, 42, 44, 46 configured to make measurements at each of the plural cell groups 30, 32, 34, 36. Each energy conversion arrangement is configured to determine a condition of at least one of: each of the plural cell groups; and the energy conversion arrangement. The condition is determined in dependence on the measurements made at each cell group and a model of each cell group.

A method of diagnosing level sensor failure in a fuel cell water trap, the method may include: determining whether a water level of a level sensor is changed in a fuel cell water trap, adding an amount of charge according to an operating time and comparing the added amount of charge with a preset threshold amount of charge, according to the result of the forcibly opening a drain valve according to determining whether a channel voltage of a specific channel is abnormal as the result of the comparison, and diagnosing a failure of the level sensor according to determining whether the channel voltage of the specific cell is recovered as a normal state when the drain valve is opened.

There is provided a fuel cell system having a fuel cell, which determines whether an operating state thereof is a low-temperature-startup operation or a normal-running operation and performs recovery control for increasing a concentration gradient of water in an electrolyte membrane of the fuel cell to be greater than that in the normal-running operation when it is determined that the operating state is the low-temperature-startup operation.

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.