Abstract: A fuel cell system includes, an oxidant feeder configured to supply an oxidant to a fuel cell, an oxidant passage which communicates with the fuel cell, a bypass passage which branches from the oxidant passage and along which part of the oxidant flows so as to bypass the fuel cell, a bypass valve which is provided in the bypass passage, an oxidant quantity-of-flow control unit which is configured to supply the quantity of flow of the oxidant corresponding to an amount of electricity required by the fuel cell, and an oxidant quantity-of-flow control unit for a sound vibration mode configured to supply a constant quantity of flow of the oxidant, and further includes a bypass valve control unit configured to control the bypass valve according to a requirement of the fuel cell when the oxidant quantity-of-flow control unit for the sound vibration mode controls the oxidant feeder.

Abstract: A fuel cell system includes a compressor for supplying the cathode gas to the fuel cell, an anode gas discharge system for discharging anode off-gas discharged from the fuel cell into a cathode gas flow passage, a pulsating operation control unit for causing a pressure of the anode gas to pulsate based on an operating state of the fuel cell, a purge control unit for purging the anode off-gas into the cathode gas flow passage based on an impurity concentration of an anode of the fuel cell and a pressure of the anode, and a compressor control unit for controlling the compressor based on a purge flow rate controlled by the purge control unit, and the purge control unit for setting the pressure of the anode to a predetermined value determined according to a pulsating state of the anode gas.

Abstract: A fuel cell system for generating power by supplying anode gas and cathode gas to a fuel cell, comprising a compressor for supplying the cathode gas to the fuel cell, a pulsating operation unit causing a pressure of the anode gas to pulsate based on an operation state of the fuel cell system, a first target pressure setting unit setting a first target pressure of the cathode gas based on a request of the fuel cell, a second target pressure setting unit setting a second target pressure of the cathode gas tor keeping a differential pressure in the fuel cell to be with in a permissible differential pressure range according to the pressure of the anode gas in the fuel cell, and a compressor control unit controlling the compressor based on the first target pressure and the second target pressure. The second target pressure setting unit sets the second target pressure based on an upper limit target pressure in pulsation on the pulsation of the pressure of the anode gas.

Abstract: A fuel cell system that generates power by supplying anode and cathode gases to a fuel cell, comprising a compressor configured to adjust a flow rate of the cathode gas supplied to the fuel cell, a relief valve configured to adjust a pressure of the cathode gas supplied to the fuel cell, a pulsation operation unit configured to pulsate an anode gas pressure, a target flow rate setting unit configured to set a target flow rate of the cathode gas on the basis of a request from the fuel cell, a first target pressure setting unit configured to set a first target pressure of the cathode gas on the basis of a request from the fuel cell, a second target pressure setting unit configured to set a second target pressure of the cathode gas for maintaining a pressure difference between an anode and a cathode of the fuel cell within a predetermined allowable pressure difference range, a target pressure setting unit configured to set the higher one of the first and second target pressures as a target pressure, and a contro

Abstract: A fuel cell system sets the larger one of a stack request compressor supply flow rate calculated based on a request of a fuel cell stack and a system request compressor supply flow rate calculated based on a request by the fuel cell system as a target compressor supply flow rate and controls a compressor according to the target compressor supply flow rate. The fuel cell system also controls a bypass valve based on a stack supply flow rate and a target stack supply flow rate to be supplied to the fuel cell stack. The fuel cell system fixes the bypass valve or limits the drive of the bypass valve when the system request compressor supply flow rate is set as the target compressor supply flow rate and the stack supply flow rate becomes smaller than the target stack supply flow rate.

Abstract: A fuel cell system includes a target pressure setting unit configured to periodically and repeatedly set a target upper limit pressure and a target lower limit pressure as a target pressure of anode gas. An upper limit pressure setting unit is configured to set the smaller one of an upper limit value based on durability performance and an upper limit value based on output performance as an upper limit pressure of the anode gas. The target pressure setting unit sets a value smaller than the upper limit value as the target upper limit pressure when the upper limit value based on the durability performance of the fuel cell is selected as the upper limit pressure of the anode gas, and sets a pressure higher than the upper limit value as the target upper limit pressure when the upper limit value based on the output performance is selected.

Abstract: A fuel cell system is configured to: calculate a target stack supply flow rate; calculate a compressor supply flow rate based on a stack supply flow rate and the target stack supply flow rate; set a larger one of the compressor supply flow rate and a lower limit flow rate, determined depending on an operation state of the fuel cell system, as a target compressor supply flow rate; control a bypass valve based on the stack supply flow rate and the target stack supply flow rate; fix the bypass valve when the stack supply flow rate is in a predetermined bypass valve fixing range, and the stack supply flow rate becomes less than the target stack supply flow rate; and release the fixation of the bypass valve when the target compressor supply flow rate becomes more than the lower limit flow rate after the bypass valve is fixed.

Abstract: A fuel cell system includes a fuel cell stack, a compressor, a cathode flow passage, a bypass flow passage branching from the cathode flow passage, thereby bypassing the stack, a bypass valve adjusting a bypass flow rate, a stack flow rate sensor detecting a flow rate to the stack, and a compressor flow rate sensor detecting a flow rate into the compressor. A flow rate for the stack depending on a state of a fuel cell and a flow rate the compressor controls depending on a requirement different from that of the stack are calculated. A control unit controls, when the flow rate required from the compressor is more than that required by the stack, the compressor based on the flow rate required from the compressor and a detected compressor flow rate, and controls the bypass valve based on the flow rate required by the stack and a detected stack flow rate.

Abstract: A fuel cell system includes, an oxidant feeder configured to supply an oxidant to a fuel cell, an oxidant passage which communicates with the fuel cell, a bypass passage which branches from the oxidant passage and along which part of the oxidant flows so as to bypass the fuel cell, a bypass valve which is provided in the bypass passage, an oxidant quantity-of-flow control unit which is configured to supply the quantity of flow of the oxidant corresponding to an amount of electricity required by the fuel cell, and an oxidant quantity-of-flow control unit for a sound vibration mode configured to supply a constant quantity of flow of the oxidant, and further includes a bypass valve control unit configured to control the bypass valve according to a requirement of the fuel cell when the oxidant quantity-of-flow control unit for the sound vibration mode controls the oxidant feeder.

Abstract: In a fuel cell system which executes a stop process of stopping an output from a fuel cell when a required power generation amount for the fuel cell is smaller than a predetermined power generation amount and supplies oxidant during a stop process period, fuel gas is intermittently supplied to a fuel electrode at a basic supply interval, which is set in advance and at which carbon dioxide is not generated in an oxidant electrode, during the stop process period.

Abstract: The fuel cell system of the present invention comprises: an electric motor, a fuel cell stack, a fuel supply unit, and a controller that controls a power-plant including the fuel cell stack and the fuel supply unit. The controller comprises further: a stack output-response request computing unit to compute a stack output-response request requested for the fuel cell stack; a stack voltage setup unit during idle-stop to set up a lower limit of stack setup-voltage during idle-stop that is set up as a stack voltage during execution of idle-stop so as to be higher as the stack output-response request is larger, and so as to be lower as the request is smaller; and an operation unit of recovering a stack voltage during idle-stop to execute a recovery operation when an actual stack voltage becomes, during execution of idle-stop, lower than the lower limit of stack setup-voltage during idle-stop.