Abstract: A fuel cell system 1 is provided with a fuel cell 10 provided with an air passage 10a, an air inflow path 21, an air outflow path 23, a compressor 22, a pressure regulating valve 24, a bypass passage 27, and a bypass valve 28. A first threshold value is calculated based on an FC inlet pressure-lower limit value. When it is judged that an FC inlet pressure-command value is lower than the first threshold value, feedback control of the opening degree of the pressure regulating valve is suspended without suspending feedback control of the opening degree of the bypass valve if it is judged that the FC pressure loss-lower limit value is larger than the bypass pressure loss-lower limit value, and feedback control of the opening degree of the bypass valve is suspended without suspending feedback control of the opening degree of the pressure regulating valve if it is judged that the bypass pressure loss-lower limit value is larger than the FC pressure loss-lower limit value.

Abstract: A fuel cell system including a fuel cell, an air compressor that supplies oxidant gas to the fuel cell, an upstream supply pipe provided with the air compressor, a downstream supply pipe connected to the upstream supply pipe and the fuel cell, an upstream discharge pipe connected to the fuel cell, a downstream discharge pipe connected to the upstream discharge pipe, a bypass pipe, a valve mechanism configured to be switchable between a supply state and a bypass state, and a controller configured to control the air compressor, the valve mechanism, and a power generation state of the fuel cell.

Abstract: Provided is a fuel cell system configured to accurately control the gas flow rate and pressure ratio of a turbo-type air compressor. The fuel cell system is a fuel cell system comprising: a fuel cell, an air compressor, an oxidant gas supply flow path, an oxidant gas discharge flow path, an oxidant gas outlet valve, a bypass flow path, a bypass valve, an atmospheric pressure sensor, an outside temperature sensor, a flow rate sensor, a rotational frequency sensor, an angle sensor, a controller, and a calculator configured to estimate the flow resistance Zd, total pressure, partial pressure and energy of each of members that are the air compressor, the oxidant gas outlet valve and the bypass valve.

Abstract: A control unit of a fuel cell (i) performs, when an estimated value of a storage amount in a storage portion of a gas-liquid separator is larger than a threshold storage amount, a first calculation process of calculating an estimated value of a discharge amount after a drain valve is opened, based on a drain speed which is determined with respect to a differential pressure in a first relationship; and (ii) performs, when the estimated value of the storage amount is equal to or smaller than the threshold storage amount, a second calculation process of calculating the estimated value of the discharge amount, based on a current drain speed determined with respect to an estimated value of a current storage amount in a second relationship that is prepared in advance and in which the drain speed decreases as the estimated value of the storage amount decreases.

Abstract: A system includes a fuel cell stack that receives a fluid, an actuator to increase or decrease a fluid temperature of the fluid, a pipe to facilitate flow of the fluid, and a memory designed to store a model of the fuel cell circuit. The system also includes an ECU that calculates mass flow values of the fluid through the fuel cell stack or the pipe based on a previously-determined mass flow value and the model of the fuel cell circuit. The ECU also calculates a plurality of pressure values corresponding to the fuel cell stack or the pipe based on the plurality of mass flow values and the model, controls the actuator position of the actuator to increase or decrease the fluid temperature based on at least one of the plurality of mass flow values and at least one of the plurality of pressure values.

Abstract: A fuel cell monitoring device includes: an impedance measuring part measuring an impedance at each fuel cell and an impedance at a fuel cell stack as a whole; a water content estimating part calculating a water content estimated value at each fuel cell using a gas diffusion resistance obtained from a measurement result about the impedance at each fuel cell, and calculating a water content reference estimated value indicating a water content in each fuel cell using a gas diffusion resistance obtained from a measurement result about the impedance at the fuel cell stack as a whole; and a determining part detecting at least either the occurrence of deterioration of catalyst in the fuel cell or the occurrence of a distribution failure of reactive gas at the fuel cell by determining based on the magnitude of the water content estimated value relative to the water content reference estimated value.

Abstract: A fuel cell system includes: a fuel cell; a voltage detector; a current detector; an alternating current signal supply unit; a phase difference calculation unit configured to calculate, based on detected alternating voltage and detected alternating current, a phase difference between the detected alternating current and the detected alternating voltage; and an estimation unit configured to estimate, in accordance with the phase difference, an electric power generation distribution feature amount representing an electric power generation distribution in a cell surface of the fuel cell, with use of a predetermined relationship between the electric power generation distribution feature amount and the phase difference. The electric power generation distribution feature amount includes a value indicating a difference between a maximum value and a minimum value of local current density in the cell surface.

Abstract: A system for controlling airflow through a fuel cell circuit includes a fuel cell stack. The system also includes a valve having a valve position that affects a pressure of the gas and a valve area corresponding to a cross-sectional area of the valve through which the gas may flow. The system also includes a memory designed to store a map or function that correlates the valve area to the valve position. The system also includes an ECU to determine or receive a desired mass flow rate of the gas through the valve, and calculate a desired valve area to achieve the desired mass flow rate. The ECU is also designed to compare the desired valve area to the map or function to determine a desired valve position that provides the desired valve area, and to control the valve to have the desired valve position.

Abstract: A fuel cell system includes a fuel cell, a supply flow passage and a discharge flow passage for anode gas, a gas-liquid separator, a discharge valve, a differential pressure detection unit configured to detect a differential pressure between an upstream side and a downstream side of the discharge valve, and a control unit. The control unit is configured to estimate an effective cross-sectional area of the discharge valve for the anode off-gas, which is decreased by an amount of water flowing into the gas-liquid separator and flowing out from the discharge valve, based on the differential pressure, and to estimate a discharge amount of the anode off-gas based on the estimated effective cross-sectional area.

Abstract: A control unit of a fuel cell (i) performs, when an estimated value of a storage amount in a storage portion of a gas-liquid separator is larger than a threshold storage amount, a first calculation process of calculating an estimated value of a discharge amount after a drain valve is opened, based on a drain speed which is determined with respect to a differential pressure in a first relationship; and (ii) performs, when the estimated value of the storage amount is equal to or smaller than the threshold storage amount, a second calculation process of calculating the estimated value of the discharge amount, based on a current drain speed determined with respect to an estimated value of a current storage amount in a second relationship that is prepared in advance and in which the drain speed decreases as the estimated value of the storage amount decreases.

Abstract: Methods, systems, and devices of a control system for gas flow. The control system controls gas flow through a fuel cell stack of a vehicle. The control system includes two or more components including one or more actuators and a fuel cell. The control system includes an electronic control unit connected to the two or more components. The control system is configured to determine initial values and previous timestep values. The control system is configured to determine or estimate a total pressure of the gas flow in each of the two or more components based on the initial values and the previous timestep values. The control system is configured to control the one or more actuators based on the total pressure of the gas flow in each of the two or more components.

Abstract: A measurement error of a water content depends on a phase difference of a low frequency. The low frequency is a lower one of two frequencies in an alternating current signal used for calculating an impedance of a cell. The phase difference is a difference between a phase of a current value of an alternating current signal applied to a fuel cell stack and a phase of a voltage value of output current. The calculated value of the water content is not used when the phase difference of the low frequency indicates that the measurement error may largely fluctuate.

Abstract: When setting a requested operating point of a compressor that supplies oxidizing gas to a fuel cell by a target flow rate and a target pressure ratio, a control section of a fuel cell system sets the target pressure ratio to be equal to or higher than a minimum pressure ratio corresponding to the target flow rate using a predetermined operation characteristic in which a minimum pressure ratio that can be realized to the flow rate that can be discharged from the compressor. In the case where a condition under which it should be determined that the minimum value of the pressure ratio in an actual operation characteristic of the compressor differs from the minimum pressure ratio in the predetermined operation characteristic is satisfied, the control section updates the minimum pressure ratio in the predetermined operation characteristic using the minimum value of the pressure ratio in the actual operation characteristic.

Abstract: Methods, systems, and devices of a control system. The control system includes a fuel cell stack. The control system includes a compressor that is configured to control and provide a total air flow within the vehicle. The compressor has an air pressure ratio and an air flow rate and operates at a speed. The control system includes an electronic control unit coupled to the fuel cell stack and the compressor. The electronic control unit is configured to determine a path associated with one or more adjustments to the air pressure ratio or the air flow rate. The electronic control unit is configured to determine a rate associated with the one or more adjustments based on the path and control at least one of the air pressure ratio, the speed or the air flow rate to operate the compressor based on the path and the rate.

Abstract: Provided is a fuel cell system including: a pressure measurement unit that acquires a measured pressure value of an anode gas at an anode gas inlet or an anode gas outlet of a fuel cell; and a water amount estimation unit. The water amount estimation unit obtains, from a plurality of circumstantial parameters including an open time of an injector provided in the anode gas supply passage and the measured pressure value measured before the injector is opened, an assumed pressure rise that is assumed based on the water amount being equal to the water amount threshold value. When a measured pressure rise of the measured pressure value resulting from opening the injector is larger than the assumed pressure rise, the water amount estimation unit estimates that the water amount is larger than the water amount threshold value.

Abstract: A system for heating or cooling a fuel cell circuit of a vehicle includes a fuel cell stack, a temperature sensor to detect a fluid temperature of the fluid, a pump to pump the fluid through the fuel cell circuit, and an ECU. The ECU is designed to determine a temperature control signal based on the fluid temperature of the fluid. The ECU is also designed to calculate a desired mass flow rate of the fluid through the fuel cell stack based on the temperature control signal. The ECU is also designed to calculate a desired pump speed of the pump based on the desired mass flow rate of the fluid through the fuel cell stack. The ECU is also designed to control the pump to pump the fluid at the desired pump speed to increase or decrease the fluid temperature of the fluid.

Abstract: The present disclosure provides a fuel cell system that achieves a stable operation of a turbo compressor. The fuel cell system includes: a fuel cell; an air supply flow path; a turbo compressor; a bypass flow path configured to discharges air by branching off from the air supply flow path; a pressure regulating valve; a bypass valve; and a control unit, the pressure regulating valve, and the bypass valve, in which the control unit calculates, from a flow rate of air supplied based on an actual rotation speed of the turbo compressor and a target flow rate of air to the fuel cell, a flow rate of excess air discharged from the bypass flow path, and determines a degree of opening of the bypass valve based on the target flow rate of air and the flow rate of excess air.

Abstract: Methods, systems, and devices of a control system for gas flow. The control system controls gas flow through a fuel cell stack of a vehicle. The control system includes two or more components including one or more actuators and a fuel cell. The control system includes an electronic control unit connected to the two or more components. The control system is configured to determine initial values and previous timestep values. The control system is configured to determine or estimate a total pressure of the gas flow in each of the two or more components based on the initial values and the previous timestep values. The control system is configured to control the one or more actuators based on the total pressure of the gas flow in each of the two or more components.

Abstract: Methods, systems, and devices of a control system. The control system includes a fuel cell stack. The control system includes a compressor that is configured to control and provide a total air flow within the vehicle. The compressor has an air pressure ratio and an air flow rate and operates at a speed. The control system includes an electronic control unit coupled to the fuel cell stack and the compressor. The electronic control unit is configured to determine a path associated with one or more adjustments to the air pressure ratio or the air flow rate. The electronic control unit is configured to determine a rate associated with the one or more adjustments based on the path and control at least one of the air pressure ratio, the speed or the air flow rate to operate the compressor based on the path and the rate.

Abstract: A system includes a fuel cell stack having a plurality of fuel cells and designed to receive a fluid and to heat the fluid. The system also includes an actuator to increase or decrease a fluid temperature of the fluid and an ECU. The ECU can determine a temperature control signal corresponding to a desired temperature of the fluid and perform a feedforward control of the actuator to increase or decrease the fluid temperature towards the desired temperature. The ECU can also determine a temperature difference between the fluid temperature and the desired temperature, and can determine a sensitivity that corresponds a change in a parameter value or the actuator position to a change in the fluid temperature. The ECU can also apply the sensitivity to the temperature difference to determine an error signal, and control the actuator based on the error signal.