Abstract: A condition-estimating device includes a first device that updates a parameter Pm[i] and an internal state Qn[i] included in a voltage estimation model of a polymer electrolyte fuel cell, a second device that successively acquires a current I[i] and a measured voltage value Vmes[i], a third device that calculates an estimated voltage value Vest[i] by using the voltage estimation model including the updated Pm[i] and Qn[i], and a fourth device that corrects a correction factor CF[i] used for the update of Pm[i] and/or Qn[i] so as to decrease |Vmes[i]?Vest[i]|. The fault-determining device includes a fault determination device that performs fault determination of a polymer electrolyte fuel cell by using Vest[i], Pm_est[i], and/or Qn_est[i]. The condition-estimating/fault-determining device includes such condition-estimating device and fault-determining device.

Abstract: A fuel cell control command device including: a catalyst potential calculation unit for calculating a catalyst potential of a cathode catalyst; a coating state calculation unit for calculating an oxide film formation amount of the catalyst; a command value candidate calculation unit for calculating a plurality of command value candidates including a combination of an estimated current, estimated total voltage, and a candidate control parameter, from which a power command value is obtained; a loss amount calculation unit for calculating an estimated loss for each combination; a provisional catalyst potential calculation unit for calculating an estimated catalyst potential for each combination; a deterioration amount calculation unit for calculating an estimated deterioration amount for each combination; and a command value calculation unit for selecting a combination having a minimum comprehensive index including the estimated loss and/or the estimated deterioration amount and outputting the selected combinati

Abstract: An operation mode of a secondary battery (BAT) is determined based on state of charge of BAT. A power generation provisional command value of fuel cell (FC) at time i is determined to maximize efficiency of FC based on system required power and state of charge of BAT at time i. An intermittent ON/OFF state at time i is determined such that switching of intermittent operation of FC is not continuous based on operation mode of BAT, the power generation provisional command value, and the system required power at time i, and an intermittent ON/OFF state at time (i?1). Further, when intermittent ON is determined at time i, the FC is stopped, and when intermittent OFF is determined at time i, a larger one is output, as the power generation command value for the FC at time i, between the power generation provisional command value and an intermittent OFF threshold.

Abstract: A fuel cell system includes a control unit that is configured to perform highland control for increasing an amount of electric power generated per unit time by a fuel cell and increasing a rotational speed of a compressor such that an operating point of the compressor falls outside a surging region, in comparison with a case where a highland condition that an outside air pressure determined from an outside air pressure-associated information is lower than an outside air pressure threshold determined in advance is not fulfilled, when the highland condition is fulfilled in starting electric power generation by the fuel cell.

Abstract: A fuel cell system includes a control unit that is configured to perform pressure reduction control for increasing a flow rate of cathode gas supplied to a fuel cell from a turbo compressor, by controlling a pressure adjusting valve such that a pressure in the fuel cell is lower when a pressure reduction condition is fulfilled than when the pressure reduction condition is not fulfilled. The pressure reduction condition is a condition that an outside air pressure determined based on outside air pressure-associated information is lower than an outside air pressure threshold determined in advance and that an amount of water determined based on water amount-associated information is equal to or larger than a water amount threshold determined in advance.

Abstract: A fuel cell system includes a fuel cell, an oxidant gas supply and discharge system, a coolant circulation system, a compressor, an atmospheric pressure sensor, and a control unit. When a measured atmospheric pressure becomes lower than a predetermined reference atmospheric pressure, the control unit executes temperature and pressure lowering control for controlling the coolant circulation system to lower the temperature of the fuel cell while controlling a pressure-regulating valve to lower a delivery pressure of the compressor.

Abstract: A fuel cell system includes a removal treatment execution unit configured to execute an oxide layer removal treatment that removes an oxide layer generated on a catalyst of a fuel cell. The removal treatment execution unit is configured to execute the oxide layer removal treatment by adjusting a voltage of the fuel cell to be within a predetermined second voltage range lower than a predetermined first voltage range that is lower than an open-circuit voltage, when an operation of the fuel cell system shifts from a first operation, where a current value of the fuel cell is zero and the flow rate is controlled to maintain the voltage of the fuel cell within the first voltage range, to a second operation, where the current value is larger than zero and the flow rate is controlled in response to an output request to the fuel cell.

Abstract: A fuel cell system includes: a flow sensor configured to measure an actual flow rate of air which is introduced into an oxidizing gas supply passage via a compressor when a fuel cell generates electric power; and a wind speed deriving unit configured to acquire a flow rate of air measured by the flow sensor in a state in which air flows from the oxidizing gas supply passage to an oxidizing gas discharge passage via the compressor and a bypass flow passage and to derive an actual wind speed of wind which is received by the fuel cell system, when the compressor stops.

Abstract: A fuel cell system includes a removal treatment execution unit configured to execute an oxide layer removal treatment that removes an oxide layer generated on a catalyst of a fuel cell. The removal treatment execution unit is configured to execute the oxide layer removal treatment by adjusting a voltage of the fuel cell to be within a predetermined second voltage range lower than a predetermined first voltage range that is lower than an open-circuit voltage, when an operation of the fuel cell system shifts from a first operation, where a current value of the fuel cell is zero and the flow rate is controlled to maintain the voltage of the fuel cell within the first voltage range, to a second operation, where the current value is larger than zero and the flow rate is controlled in response to an output request to the fuel cell.

Abstract: A fuel cell system includes a control unit that is configured to perform pressure reduction control for increasing a flow rate of cathode gas supplied to a fuel cell from a turbo compressor, by controlling a pressure adjusting valve such that a pressure in the fuel cell is lower when a pressure reduction condition is fulfilled than when the pressure reduction condition is not fulfilled. The pressure reduction condition is a condition that an outside air pressure determined based on outside air pressure-associated information is lower than an outside air pressure threshold determined in advance and that an amount of water determined based on water amount-associated information is equal to or larger than a water amount threshold determined in advance.

Abstract: A fuel cell system includes: a flow sensor configured to measure an actual flow rate of air which is introduced into an oxidizing gas supply passage via a compressor when a fuel cell generates electric power; and a wind speed deriving unit configured to acquire a flow rate of air measured by the flow sensor in a state in which air flows from the oxidizing gas supply passage to an oxidizing gas discharge passage via the compressor and a bypass flow passage and to derive an actual wind speed of wind which is received by the fuel cell system, when the compressor stops.

Abstract: A fuel cell system includes a control unit that is configured to perform highland control for increasing an amount of electric power generated per unit time by a fuel cell and increasing a rotational speed of a compressor such that an operating point of the compressor falls outside a surging region, in comparison with a case where a highland condition that an outside air pressure determined from an outside air pressure-associated information is lower than an outside air pressure threshold determined in advance is not fulfilled, when the highland condition is fulfilled in starting electric power generation by the fuel cell.

Abstract: A fuel cell system includes a fuel cell, an oxidant gas supply and discharge system, a coolant circulation system, a compressor, an atmospheric pressure sensor, and a control unit. When a measured atmospheric pressure becomes lower than a predetermined reference atmospheric pressure, the control unit executes temperature and pressure lowering control for controlling the coolant circulation system to lower the temperature of the fuel cell while controlling a pressure-regulating valve to lower a delivery pressure of the compressor.