Abstract: A fuel cell system includes a fuel cell including a plurality of stacked cells, a fuel gas supply unit configured to supply fuel gas to a supply port of the fuel cell and return the fuel gas exhausted through an exhaust port of the fuel cell, and a controller configured to control an operation of the fuel gas supply unit. The controller is configured to execute a drain process for draining residual water accumulated in the fuel cell through the exhaust port. In the drain process, a first process in which the fuel gas is supplied to the fuel cell until a pressure in the fuel cell reaches a predetermined threshold pressure and a second process in which the pressure in the fuel cell is reduced after the first process are repeatedly executed.

Abstract: A fuel cell system may include: a fuel cell unit connected to an output terminal; a battery unit connected to the fuel cell unit in parallel: and a controller configured to control the fuel cell unit to maintain an output voltage of the fuel cell unit at an idling voltage which is higher than zero and lower than an output voltage of the battery unit when a target output power is lower than an output power lower limit set for the fuel cell unit.

Abstract: A vehicle may include: a fuel tank; a first fuel inlet connected to the fuel tank and configured to connect to a fuel supply nozzle; and a second fuel inlet connected to the fuel tank and configured to connect to the fuel supply nozzle. An inner diameter of the second fuel inlet may be smaller than an inner diameter of the first fuel inlet.

Abstract: A fuel cell vehicle may include: a fuel cell unit; a battery unit connected to an output terminal of the fuel cell unit in parallel; a traction motor configured to be driven by electric power supplied from at least one of the fuel cell unit and the battery unit; and a controller configured to control the fuel cell unit to maintain a FC voltage outputted from the fuel cell unit at an idling voltage which is higher than zero and lower than a battery voltage outputted from the battery unit while driving of the traction motor is prohibited.

Abstract: The present invention provides a technique capable of satisfying both the restoration of an output voltage of a fuel cell and an improvement of electric power responsiveness in a fuel cell system in a situation in which its operation status is restored to a normal operation from an operation having low power generation efficiency. A controller updates a lower limit voltage threshold in accordance with the restoration of an FC voltage until the operation status is restored to a normal operation from an operation having low power generation efficiency, such as an intermittent operation and a warmup operation (step S1). The controller increases an FC current in accordance with the updated lower limit voltage threshold (steps S2 and S3) to thereby satisfy both the requirements of the restoration of the output voltage of the fuel cell stack and the improvement of the electric power responsiveness.

Abstract: A technique that suppresses excessive water drainage from a fuel cell is provided. A water drainage device that drains water from inside of a fuel cell includes: a purge gas supply system; an operation unit; a water drainage controller; and a water content acquirer. The operation unit receives a water drainage command from a water drainage switch configured to control execution of a purge process by the purge gas supply system. When the water content obtained by the water content acquirer is equal to or lower than a predetermined value, the water drainage controller performs either one of: (i) invalidating the received water drainage command; and (ii) changing a processing condition of the purge process to decrease an amount of water drained by the purge process, compared with an amount of water drainage when the obtained water content is higher than the predetermined value.

Abstract: A fuel cell system comprises a fuel cell; a fuel cell controlling converter; an oxidizing gas supplier that is configured to supply an oxidizing gas to the fuel cell; and a controller that is configured to control a voltage and a current value of the fuel cell. In a first power generation state, the controller sets the voltage and the current value of the fuel cell according to a required output, based on a current-voltage characteristic of the fuel cell. In a second power generation state, the controller sets the voltage and the current value of the fuel cell according to the required output and a required amount of heat, to a voltage and a current value that provide a lower power generation efficiency than a power generation efficiency in the first power generation state. The controller reduces the required amount of heat in a process of changing over a power generation state from the second power generation state to the first power generation state.

Abstract: There is provided a fuel cell system, wherein a controller configured to set the flow volume of a fluid in an anode flow path at an outlet of an anode of the fuel cell to a first flow volume, then set thereafter the flow volume of the fluid in the anode flow path at the outlet of the anode to a second flow volume which is smaller than the first flow volume, and discharge the water in the hydrogen discharge flow path by opening an exhaust and drain valve while the fluid is flowing at the second flow volume.

Abstract: The method comprises: determining whether or not an inlet temperature is equal to or above a lower-limit temperature of a temperature range in which generated water does not freeze within the fuel cell; and adjusting the flow rate of the cooling medium in the circulation flow path to become more than the normal flow rate when it is determined that the inlet temperature is equal to or above the lower-limit temperature, and adjusting the flow rate of the cooling medium in the circulation flow path to be equal to or below the normal flow rate when it is determined that the inlet temperature is not equal to or above the lower-limit temperature.

Abstract: A fuel cell system comprises: a fuel cell; a cooling liquid supply flow path for supplying cooling liquid to the fuel cell; a radiator for cooling the cooling liquid; a first temperature sensor, provided at an outlet of the radiator, for measuring a temperature of the cooling liquid; an ambient temperature sensor; and a controller. The controller executes: estimating a temperature of the cooling liquid inside the cooling liquid supply flow path based on an ambient temperature measured by the ambient temperature sensor; acquiring a temperature of the cooling liquid inside the cooling liquid supply flow path based on the temperature measured by the first temperature sensor after it is determined that the cooling liquid within the radiator has reached the first temperature sensor; and adjusting a flow rate of the cooling liquid based on the estimated temperature or the acquired temperature of the cooling liquid.

Abstract: At an ordinary stop time of a fuel cell system, a controller of the fuel cell system completes an ordinary stop process that includes at least one of a water drainage process that discharges water from at least one of the fuel gas flow path and the oxidizing gas flow path and a cathode sealing process that seals the oxidizing gas flow path, and subsequently stops the fuel cell system. When the fuel cell system satisfies a predetermined emergency stop condition, the controller does not perform at least part of the ordinary stop process but performs an emergency stop process that sets the fuel cell system to be restarted after elapse of a first time period since a stop of the fuel cell system and subsequently stops the fuel cell system. The controller restarts the fuel cell system after elapse of the first time period since stop of the fuel cell system and performs a restart process that performs the ordinary stop process.

Abstract: The operation control method of a fuel cell includes acquiring a startup temperature of the fuel cell; acquiring a present temperature of the fuel cell; setting a present target operation point of the fuel cell that is identified by an output voltage value and an output current value based on the startup temperature, or based on the startup temperature and the present temperature; controlling at least one of the flow of the reaction gas supplied to the fuel cell, and an output voltage of the fuel cell so that the operation point of the fuel cell becomes the target operation point, and setting the target operation point includes a process of setting an operation point having a low output voltage value as the target operation point when the startup temperature is low as compared to the case when the startup temperature is high, if the present temperature is the same.

Abstract: A fuel cell system includes: a fuel cell supplied with fuel gas for power generation; a fuel supply flow passage flowing fuel gas, supplied from a fuel supply source, to the fuel cell; a pressure regulating valve regulating a pressure of fuel gas flowing through the fuel supply flow passage; a fuel circulation flow passage returning gas, emitted from the fuel cell, to the fuel supply flow passage; a circulation pump delivering gas in the fuel circulation flow passage to the fuel supply flow passage; an emission valve emitting gas in the fuel circulation flow passage to an outside; and a control device controlling the pressure regulating valve, the circulation pump and the emission valve such that the sum of losses of crossover hydrogen, circulation pump power and purge hydrogen is minimum while a hydrogen stoichiometric ratio required for power generation of the fuel cell is ensured.

Abstract: An object is to readily provide an output limit of a fuel cell by using temperature of a cooling medium, while improving the startability of a fuel cell. When a cell voltage obtained from an end-portion cell of a fuel cell is equal to or lower than a first threshold value, a controller of a fuel cell system sets an output limit amount used for output limit of the fuel cell to be smaller than an output limit amount according to temperature of a cooling medium measured by a temperature measurement unit.

Abstract: A method includes predicting, while fuel cell system is operated, whether or not the outside temperature becomes equal to or less than a first predetermined temperature; performing, when it is predicted that the outside temperature becomes equal to or less than the first predetermined temperature, residual water scavenging processing on only an oxidizer gas supply/discharge mechanism and thereafter stopping the operation of the fuel cell system; predicting, after the stop of the operation of the fuel cell system, whether or not the temperature of a predetermined component included in the fuel cell system becomes equal to or less than a second predetermined temperature; and performing the residual water scavenging processing on the fuel gas supply/discharge mechanism when it is predicted that the temperature of the predetermined component becomes equal to or less than the second predetermined temperature.

Abstract: There is provided a fuel cell system. The fuel cell system includes a gas pump that is configured to have a rotating body and circulate an exhaust gas discharged from a fuel cell and is provided in a circulation passage configured to connect a discharge passage of the exhaust gas with a fuel gas supply passage. When temperature of the fuel cell is higher than a reference temperature that is a temperature that allows water to be introduced in a supercooled state into the gas pump, the fuel cell system controls the rotation speed of the rotating body of the gas pump to a first rotation speed corresponding to a power generation demand for the fuel cell. When the temperature of the fuel cell is not higher than the reference temperature, the fuel cell system controls the rotation speed of the rotating body of the gas pump to a second rotation speed that is lower than the first rotation speed.

Abstract: A fuel cell system comprises: a fuel cell formed of a plurality of cells stacked therein, each cell generating electric power through an electrochemical reaction between a fuel gas and an oxidant gas; a cell monitor capable of detecting a group voltage for each group wherein each group is composed of two or more cells; and an estimation device that estimates a minimum cell voltage. The estimation device comprises a maximum cell voltage estimation part that estimates a maximum cell voltage, and the estimation device estimates the minimum cell voltage by using an estimated value of the maximum cell voltage and a minimum group-average voltage, where an average voltage of a group having the lowest voltage value among the group voltages is defined as the minimum group-average voltage.

Abstract: The present invention enables the determination of an operating point of a fuel cell so as to prioritize the fulfillment of an amount of required power generation while avoiding various limitations, such as a current limit, in a fuel cell system that warms up the fuel cell by a low efficiency operation. A controller 70 multiplies a voltage command value Vcom obtained in step S3 by a current command value Icom obtained in step S1, then, this is divided by a final voltage command value Vfcom obtained in step S4, thereby obtaining a final current command value Ifcom to determine an operating point (Ifcom, Vfcom) during a warm-up operation (step S5), and then the process ends.

Abstract: A fuel cell system includes: a fuel cell outputting a current; a supply unit supplying oxidant gas; a flow-amount measurement unit measuring a flow amount of the oxidant gas; and a controller that feed-back controls the supply unit such that a measured flow-amount value converges toward a target flow-amount value, wherein the controller determines an acceptable current value in accordance with the measured flow-amount value, restricts the current to the acceptable current value or less, controls the current in accordance with a requested current value of the fuel cell; and performs a changing-suppression processing, when a condition continues for a predetermined period, the condition including that a changing width of the requested current value is equal to or less than a first value and a difference between the requested current value and the acceptable current value is equal to or less than a second value.

Abstract: To provide technology that is capable of inhibiting a decrease in starting properties of a pump in a low-temperature environment. A fuel cell system is equipped with a control unit, a fuel cell, and a pump. The control unit acquires the temperature of the fuel cell as a parameter expressing the temperature of the pump while operation of the fuel cell is stopped. The control unit rotates rotation body of the pump when it is detected that the temperature of the pump is a threshold value or less set within a predetermined range lower than the freezing point based on the detected temperature of the fuel cell.