A control unit estimates a discharged fuel gas amount, i.e., an amount of fuel gas discharged from the outlet of a cathode flow field, of a fuel exhaust gas introduced from a communication flow path to the inlet of the cathode flow field and then flowing through a cathode. The control unit calculates an oxygen-containing gas amount necessary for dilution at the time of discharge into the atmosphere, from the estimated discharged fuel gas amount, and sets a discharge amount of the air pump, based on the calculated oxygen-containing gas amount.

An air supply system, comprising at least two air blowers and at least two communication valves; wherein one air blower is connected to a main air passage through the corresponding communication valve; and at least one other is connected to a reformer air passage and a stack air passage through at least one other communication valve, respectively. At least two air blowers are provided to connect the at least two communication valves.

A method of operating power system includes generating compressed air, providing the compressed air and fuel to fuel cell power modules, and providing a cathode exhaust from the power modules to a heat exchanger.

A fuel cell system includes: a fuel cell stack; a fuel tank; a fuel pipe connecting the fuel cell stack and the fuel tank; a fuel regulator disposed in the fuel pipe and configured to regulate a flow rate of fuel gas to be supplied from the fuel tank to an anode; a fuel stop valve disposed in the fuel pipe; and a controller. The controller is configured to execute, when activating or stopping the fuel cell stack: a first process of opening the fuel stop valve and the fuel regulator; a second process of closing the fuel stop valve and the fuel regulator when an anode internal pressure reaches a predetermined first anode pressure; and a third process of outputting a signal indicating occurrence of fuel leakage when the anode internal pressure after a predetermined first period is lower than a predetermined second anode pressure.

A fuel cell control method and system based on model prediction control are provided. The method includes: (1) obtaining data required for control; (2) determining whether the data required for control are received completely; (3) estimating an internal state of a fuel cell based on outlet pressure of an air compressor and a voltage of the fuel cell to obtain a state estimation result; (4) calculating a target outlet flow of the air compressor and a target current of the fuel cell with a model prediction control algorithm based on the state estimation result; (5) calculating a control voltage of the air compressor, and a target outlet flow of the air compressor; and (6) tracking power of the fuel cell based on the target current of the fuel cell, and controlling air supply of the fuel cell based on the control voltage of the air compressor.

The present invention relates to a determination device (1; 1′) for a fuel cell system (2; 2′) having a fuel cell stack (4), comprising a virtual moisture sensor (7) for recording predefined determination values and a computing unit (10) for calculating a moisture value in a cathode inlet region (5) upstream of a cathode section of the fuel cell stack (4) based on the recorded determination values. The invention further relates to a fuel cell system (2; 2′) having such a determination device (1; 1′), methods for determining the moisture value, a computer program product (11) and a storage means having a computer program product (11) stored thereon.

A control unit estimates a discharged fuel gas amount, i.e., an amount of fuel gas discharged from the outlet of a cathode flow field, of a fuel exhaust gas introduced from a communication flow path to the inlet of the cathode flow field and then flowing through a cathode. The control unit calculates an oxygen-containing gas amount necessary for dilution at the time of discharge into the atmosphere, from the estimated discharged fuel gas amount, and sets a discharge amount of the air pump, based on the calculated oxygen-containing gas amount.

A fuel cell control method and system based on model prediction control are provided. The method includes: (1) obtaining data required for control; (2) determining whether the data required for control are received completely; (3) estimating an internal state of a fuel cell based on outlet pressure of an air compressor and a voltage of the fuel cell to obtain a state estimation result; (4) calculating a target outlet flow of the air compressor and a target current of the fuel cell with a model prediction control algorithm based on the state estimation result; (5) calculating a control voltage of the air compressor, and a target outlet flow of the air compressor; and (6) tracking power of the fuel cell based on the target current of the fuel cell, and controlling air supply of the fuel cell based on the control voltage of the air compressor.

A system regulating pressure of a reactor for hightemperature electrolysis or co-electrolysis (HTE) or to an SOFC fuel-cell stack operating under pressure. The operation of the system includes: regulating upstream of one of the chambers, a flow rate of moisture-containing gas DH to guarantee electrochemical stability of a preset operating point; and controlling pressure by virtue of valves arranged downstream of the stack, for regulating gases including the moisture-containing gas, and which are generally hot.

A fuel cell system mounted in a mobile object is equipped with a bypass flow passage that establishes communication between an air compressor and an exhaust gas flow passage, and a valve that adjusts an amount of air supplied to the bypass flow passage. A control unit performs a process for increasing a flow rate of air caused to flow through the bypass flow passage, by controlling a drive amount of the air compressor and the opening degree of the valve, when an outside air temperature is equal to or lower than a threshold and a speed of the mobile object is equal to or lower than a determination speed. In the process, a flow rate of air at a first temperature that is lower than a second temperature that is equal to or lower than the threshold is larger than a flow rate of air at the second temperature.