Abstract: A cooling water temperature of a fuel cell 10 is detected by a sensor 94d. Based on the outside air temperature, a first threshold temperature and a second threshold temperature lower than the first threshold temperature are calculated. When it is judged that the cooling water temperature is lower than the first threshold temperature and higher than the second threshold temperature, first warmup processing is performed. When it is judged that the cooling water temperature is lower than the second threshold temperature, second warmup processing with an amount of heat generation greater than the first warmup processing is performed.

Abstract: A fuel cell system includes a fuel cell stack and a control device. The control device raises the voltage of the fuel cell stack until a predetermined voltage condition is met, by supplying a cathode with an oxidant gas before current sweep is started when the fuel cell system is started and a value measured by a temperature sensor is equal to or less than a temperature determined in advance. The control device executes stand-by control, in which a current command value is kept constant, when a measured voltage value reaches a control start voltage value smaller than a voltage command value in a transition period, and ends the stand-by control by permitting a change in the current command value when the measured voltage value reaches a permission voltage value equal to or more than the voltage command value during execution of the stand-by control.

Abstract: A fuel cell system includes a fuel cell stack and a control device that controls operation of the fuel cell system based on a measured voltage value measured by a voltage sensor. When the fuel cell system is started and a value measured by a temperature sensor is equal to or less than a temperature determined in advance, the control device raises the voltage of the fuel cell stack until a voltage condition determined in advance is met, by supplying a cathode with an oxidant gas before current sweep is started. The control device sets a voltage command value and a current command value such that an operation point of the fuel cell stack is on an equal power line of the fuel cell stack when the operation point is caused to transition in at least a part of a transition period.

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.

Abstract: A fuel cell system includes a controller which controls operations of an oxidizing gas supply/discharge system and a fuel gas supply/discharge system, and controls power generation of a fuel cell stack, and, when detecting a fuel gas concentration abnormality that a fuel gas concentration in an exhaust gas exceeds an allowable value during the power generation of the fuel cell stack, the controller increases a flow rate of air fed by an air compressor, and controls an opening of a bypass valve to execute exhaust gas dilution control for increasing a ratio of the flow rate of the air flowing out from the bypass piping to an exhaust gas piping with respect to the flow rate of the air to be supplied to the fuel cell stack.

Abstract: A fuel cell system includes a fuel cell stack, an oxidizing gas supply system, a fuel gas supply system, a current control circuit configured to control an output current of the fuel cell stack, a control unit configured to control power generation of the fuel cell stack, and the output current of the current control circuit, the control unit controlling the current control circuit to adjust the output current thereby adjusting a heating value of the fuel cell stack; and a monitoring unit configured to monitor abnormal fuel gas generation, the abnormal fuel gas generation corresponding to a state where the fuel gas in excess of a predetermined allowable amount exists in the cathode. When the monitoring unit detects the abnormal fuel gas generation during execution of a warm-up operation to allow the fuel cell stack to generate heat with a predetermined target heating value, the control unit reduces the output current by reducing the target heating value.

Abstract: A fuel cell system includes a fuel cell stack, an oxidizing gas supply system, a cooling medium circulation pump, a stack temperature acquisition unit, and a control unit. After a first time point when a change in an acquisition temperature turns from downward to upward after the change in the acquisition temperature turns from upward to downward for the first time after the start of the warm-up operation processing, the control unit sets a decrease speed in cases of decreasing a rotational speed of the cooling medium circulation pump to a smaller value than a value set before the first time point.

Abstract: A fuel cell system includes a fuel cell in which cells are stacked, a voltage sensor that detects a voltage in unit of one or more of the cells, a control unit that determines an operating point of the fuel cell and causes the fuel cell to operate. The control unit causes the fuel cell to operate at a low efficiency operating point having a lower efficiency than an efficiency of a reference operating point in a warm-up operation. In the warm-up operation, the control unit calculates a total number of the cells in which the voltage detected by the voltage sensor is equal to or less than a predetermined first reference voltage and calculates an exhaust hydrogen concentration based on the total number or the cells.

Abstract: A braking control unit of a fuel cell vehicle is configured to, in a period during which the fuel cell vehicle is being braked in response to a braking request, (i) when an estimated amount of stagnant water is less than a predetermined second water amount less than a first water amount, limit an upper limit electric power of a regenerated electric power resulting from regenerative operation to a predetermined first value or below, and (ii) when the estimated amount of stagnant water is greater than or equal to the second water amount, execute an upper limit changing process of setting an upper limit electric power to a second value lower by a predetermined value than the first value.

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.