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 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 system for controlling gas flow in a fuel cell circuit includes a fuel cell stack, a pressure sensor, and a valve to adjust a flow of gas through the fuel cell circuit. The system further includes an ECU designed to estimate pressure values of the gas at multiple locations in the fuel cell circuit based on the detected pressure of the gas and based on flow resistance values (including at the valve), the estimated pressure values including an estimated sensor pressure value at a location of the pressure sensor. The ECU is further designed to determine a pressure deviation between the detected pressure and the estimated sensor pressure value. The ECU is further designed to adjust the flow resistance value of the valve to determine a final flow resistance value of the valve that causes the pressure deviation to reach or drop below a threshold deviation amount.

Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply path, an injector, an ejector, a circulation path, a pressure difference detection unit that detects a pressure difference between an ejector inlet port pressure and an ejector outlet port pressure, and a control device. The control device calculates a required circulation flow rate that is required for a fuel off gas supplied from the fuel cell stack to the ejector, based on a required load for the fuel cell stack, calculates an estimated circulation flow rate that is an estimated flow rate of the fuel off gas supplied from the fuel cell stack to the ejector, based on the required load and the pressure difference, and increases the flow rate of a fuel gas supplied from the injector to the fuel cell stack when the estimated circulation flow rate is lower than the required circulation flow rate.

Abstract: A fuel gas supply system for a fuel cell includes an injector, an inlet pressure acquisition unit, a discharge valve, a hydrogen partial pressure acquisition unit, and a controller. The controller is configured to stop driving the injector when a hydrogen partial pressure reaches or exceeds a first upper limit value in a state where the injector is being driven, and start driving the injector when the hydrogen partial pressure falls to or below a first lower limit value in a state where the injector is stopped. The controller is configured to open the discharge valve when an inlet pressure reaches or exceeds a second upper limit value in a state where the discharge valve is closed, and close the discharge valve when the inlet pressure falls to or below a second lower limit value in a state where the discharge valve is open.

Abstract: A fuel cell system is equipped with a control unit that controls a rotational speed of the turbo compressor that supplies air to an air supply flow passage and an opening degree of at least one valve that adjusts a flow rate and a pressure of the air supplied to a fuel cell such that an operating point of the turbo compressor becomes a target operating point. The control unit sets the target operating point within an operating point range that is on the higher flow rate side than at least part of a first region where an amount of change in flow rate is larger than a predetermined value when a pressure ratio of the turbo compressor is changed by a predetermined amount at a same rotational speed, on a higher flow rate side than a surging region, when a predetermined condition is fulfilled.

Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply path, an injector, an ejector, a circulation path, an outlet port pressure detection unit, and a control device. The control device stops driving the injector when an ejector outlet port pressure is equal to or more than a required upper limit value with the injector driven, and drives the injector when the ejector outlet port pressure is equal to or less than a required lower limit value with the injector stopped. The control device reduces the required upper limit value stepwise and reduces the required lower limit value stepwise in a range defined by a first target upper limit value and a second target upper limit value when a required load is varied from a first required load to a second required load and a load reduction amount is more than a first predetermined load.

Abstract: Systems and methods for controlling fluid flow in a fuel cell circuit of a vehicle. A system may have a fuel cell stack configured to receive hydrogen gas. The system may have a current sensor configured to detect current flowing through the fuel cell stack. The system may have a plurality of actuators, which may include at least one injector, a pump, and a shut valve. The system may have an electronic control unit (ECU). The ECU may estimate pressures of the hydrogen gas and non-hydrogen gases in the circuit. The ECU may determine a current increase rate based on the detected current. The ECU may apply a compensatory hydrogen gas stoic to a base hydrogen gas stoic to meet a target hydrogen gas stoic by controlling one or more of the actuators based on the estimated pressures when the current increase rate is above a predetermined threshold value.

Abstract: A system for providing oxygen to a fuel cell circuit includes a compressor and a fuel cell stack having a plurality of fuel cells. The system also includes a plurality of pipes and a pressure sensor designed to detect pressure at a first location. The system also includes a memory to store a model of the fuel cell circuit and an ECU. The ECU determines a control signal corresponding to desirable operation of the compressor and determines flow values of the gas through each component based on the detected pressure and the model of the fuel cell circuit. The ECU also determines pressure values of each component based on the determined flow values and the model of the fuel cell circuit. The ECU also controls operation of the compressor based on the control signal, at least one of the flow values, and at least one of the pressure values.

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: A system for controlling gas flow in a fuel cell circuit includes a fuel cell stack and a valve designed to adjust gas flow through the circuit. The system further includes an ECU that is designed to determine a target flow rate of the gas through the valve. The ECU is further designed to determine a flow compensation value corresponding to an amount of compensation of the target flow rate of the gas through the valve that compensates for fluid accumulation or decumulation in the fuel cell circuit. The ECU is further designed to determine a compensated target flow rate of the gas through the valve based on the target flow rate and the flow compensation value. The ECU is further designed to determine a desired valve position of the valve based on the compensated target flow rate and to control the valve to have the desired valve position.

Abstract: Systems and methods for controlling fluid flow in a fuel cell circuit of a vehicle. A system may have a fuel cell stack configured to receive hydrogen gas. The system may have a current sensor configured to detect current flowing through the fuel cell stack. The system may have a plurality of actuators, which may include at least one injector, a pump, and a shut valve. The system may have an electronic control unit (ECU). The ECU may estimate pressures of the hydrogen gas and non-hydrogen gases in the circuit. The ECU may determine a current increase rate based on the detected current. The ECU may apply a compensatory hydrogen gas stoic to a base hydrogen gas stoic to meet a target hydrogen gas stoic by controlling one or more of the actuators based on the estimated pressures when the current increase rate is above a predetermined threshold value.

Abstract: A system for controlling gas flow in a fuel cell circuit includes a fuel cell stack and a valve designed to adjust gas flow through the circuit. The system further includes an ECU that is designed to determine a target flow rate of the gas through the valve. The ECU is further designed to determine a flow compensation value corresponding to an amount of compensation of the target flow rate of the gas through the valve that compensates for fluid accumulation or decumulation in the fuel cell circuit. The ECU is further designed to determine a compensated target flow rate of the gas through the valve based on the target flow rate and the flow compensation value. The ECU is further designed to determine a desired valve position of the valve based on the compensated target flow rate and to control the valve to have the desired valve position.

Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply path, an injector, an ejector, a circulation path, a pressure difference detection unit that detects a pressure difference between an ejector inlet port pressure and an ejector outlet port pressure, and a control device. The control device calculates a required circulation flow rate that is required for a fuel off gas supplied from the fuel cell stack to the ejector, based on a required load for the fuel cell stack, calculates an estimated circulation flow rate that is an estimated flow rate of the fuel off gas supplied from the fuel cell stack to the ejector, based on the required load and the pressure difference, and increases the flow rate of a fuel gas supplied from the injector to the fuel cell stack when the estimated circulation flow rate is lower than the required circulation flow rate.

Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply path, an injector, an ejector, a circulation path, an outlet port pressure detection unit, and a control device. The control device stops driving the injector when an ejector outlet port pressure is equal to or more than a required upper limit value with the injector driven, and drives the injector when the ejector outlet port pressure is equal to or less than a required lower limit value with the injector stopped. The control device reduces the required upper limit value stepwise and reduces the required lower limit value stepwise in a range defined by a first target upper limit value and a second target upper limit value when a required load is varied from a first required load to a second required load and a load reduction amount is more than a first predetermined load.

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 system for controlling gas flow in a fuel cell circuit includes a fuel cell stack, a pressure sensor, and a valve to adjust a flow of gas through the fuel cell circuit. The system further includes an ECU designed to estimate pressure values of the gas at multiple locations in the fuel cell circuit based on the detected pressure of the gas and based on flow resistance values (including at the valve), the estimated pressure values including an estimated sensor pressure value at a location of the pressure sensor. The ECU is further designed to determine a pressure deviation between the detected pressure and the estimated sensor pressure value. The ECU is further designed to adjust the flow resistance value of the valve to determine a final flow resistance value of the valve that causes the pressure deviation to reach or drop below a threshold deviation amount.

Abstract: An FC (fuel cell) system includes: an FC; a radiator configured to cool a CL (cooling liquid); an ion exchanger provided in a BFP (bypass flow path) branched off from a CFP (circulation flow path) for allowing the CL to circulate between the FC and the radiator; a multi-way valve provided in a branching point at which the BFP is branched off from the CFP; and a pump which circulates the CL. A percentage of the CL that is made to flow through the BFP can be controlled by the multi-way valve. In a case in which a stop time is longer than a threshold time when the FC system is started up, after the CL is circulated through the radiator, the CL is circulated through the BFP at the percentage of 80% or more until electrical conductivity of the CL becomes smaller than a threshold electrical conductivity.

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: Provided is a fuel cell system including: a fuel cell; a reactant gas supply section; a converter; an alternating-current superimposing unit; a phase difference deriving unit configured to derive a phase difference that is a phase lag of an alternating-current voltage relative to an alternating current in an alternating-current component output from the fuel cell; and a first inference unit. The first inference unit infers that the fuel cell is in an inappropriate wet state, when the absolute value of an amount of change in the phase difference has become equal to or larger than a predetermined criterion value immediately after the magnitude of a change in the value of at least one of parameters that are a flow rate of a reactant gas, a stoichiometric ratio, and an output current has exceeded a predetermined criterion.