Nissan Motor Company Limited

Yoshitomo Asai

Hiroshi Takeda

Mitsunori Kumada

Shinichi Makino

Hayato Chikugo

Michihiko Matsumoto

Takeaki Obata

Yasushi Ichikawa

Yousuke Tomita

A fuel cell system includes a supply valve for supplying an anode gas into an anode system, a purge valve for discharging an off-gas from the anode system, a pressure detecting portion configured to estimate or measures a pressure inside the anode system, a supply valve control portion configured to control an open/close operation of the supply valve based on a load of the fuel cell, a purge flow rate estimating portion configured to estimate a purge flow rate of the off-gas discharged from the anode system through the purge valve based on a pressure decrease inside the anode system in a supply valve close state, and a purge valve control portion configured to open the purge valve in synchronization with the supply valve close state.

Fuel cell system

In order to improve estimation accuracy of a purging amount, a fuel cell system comprises a supply valve that controls a supply of an anode gas into an anode system, a purge valve that discharges an off-gas from the anode system, a pressure detecting unit configured to estimate or measures a pressure inside the anode system, and a purging amount estimating unit configured to estimate a purging amount of the off-gas discharged from the anode system through the purge valve based on a pressure change inside the anode system during a purge valve close duration in a supply valve open state and a pressure change inside the anode system during a purge valve close duration in a supply valve close state.

Fuel cell system and control method thereof

A fuel cell system comprising: a supply valve for supplying the anode gas into an anode system of the fuel cell system; a purge valve for discharging an off-gas from the anode system; a pressure detecting portion that estimates or measures a pressure inside the anode system; and a hydrogen concentration estimating portion that estimates a hydrogen concentration inside the anode system based on a pressure decrease during a purge valve open duration in a supply valve close state.

Fuel cell system and method thereof

A fuel cell system includes a compressor, a relief valve that adjusts a pressure of a cathode gas, a pulsation operation unit that pulsates an anode gas pressure, a target flow rate setting unit that sets a target flow rate of the cathode gas, a first target pressure setting unit that sets a first target pressure of the cathode gas, a second target pressure setting unit that sets a second target pressure of the cathode gas for maintaining a pressure difference between an anode and a cathode within a predetermined allowable range, a target pressure setting unit that sets the higher one of the first and second target pressures as a target pressure, and a control unit that controls the compressor on the basis of the target flow rate and a limitative pressure obtained by limiting pulsation of the target pressure.

Fuel cell system and method of controlling fuel cell system

A fuel cell system includes a supply unit configured to supply cathode gas to a fuel cell, a bypass valve configured to bypass the cathode gas to be supplied to the fuel cell by the supply unit, a detection unit configured to detect a state of the cathode gas to be supplied to the fuel cell without being bypassed by the bypass valve, a pressure adjusting unit configured to adjust a pressure of the cathode gas to be supplied to the fuel cell, a calculation unit configured to calculate a target flow rate and a target pressure of the cathode gas to be supplied to the fuel cell according to an operating state of the fuel cell, an operating state control unit configured to control an operation amount of at least one of the pressure adjusting unit and the supply unit on the basis of a flow rate and the pressure of the cathode gas detected by the detection unit and the target flow rate and the target pressure calculated by the calculation unit, a bypass valve control unit configured to open and close the bypass valve on the basis of the flow rate of the cathode gas detected by the detection unit and the target flow rate calculated by the calculation unit, and a pressure compensation unit configured to compensate for the pressure of the cathode gas to be supplied to the fuel cell by increasing the at least one operation amount controlled by the operating state control unit or by decreasing an opening speed of the bypass valve when the bypass valve is opened.

Fuel cell system with cathode bypass valve and control method for fuel cell system

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.

Fuel cell system and control method for fuel cell system

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.

A fuel cell system () includes a hydrogen supply valve () that controls a supply of the anode gas into an anode system, a purge valve () that discharges an off-gas from the anode system, a pressure detecting unit () configured to measure a pressure inside the anode system, and a purge flow rate estimating unit () configured to estimate a purge flow rate of the off-gas discharged from the anode system through the purge valve () based on a pressure decrease in a purge valve open state and a pressure decrease in a purge valve close state when an anode gas supply into the anode system stops.

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.

A fuel cell system includes a fuel cell, an air supplier, an air passage connected to the fuel cell, air supplied from the air supplier flowing in the air passage, a bleed passage branched off from the air passage on a side upstream of the fuel cell and joining the air passage on a side downstream of the fuel cell, part of the air supplied by the air supplier flowing in the bleed passage in such a manner as to circumvent the fuel cell, a bleed valve provided in the bleed passage, the bleed valve regulating the amount of air flowing in the bleed passage, an air supplier control unit which controls the air supplier to supply a predetermined amount of air, a wetness reduction determination unit which determines whether or not it is necessary to reduce a degree of wetness of the fuel cell, and a bleed amount control unit which reduces an opening of the bleed valve when the degree of wetness of the fuel cell needs to be reduced.

Fuel cell system and control method for the same

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 for keeping a differential pressure in the fuel cell to be within 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.

Fuel cell system and control method of fuel cell system

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.

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.

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.

Fuel cell system including controller to prevent over-discharge of battery and lowering in drivability upon recovering from idle stop

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.

Growing community of inventors

Kanagawa, Japan

Yoshitomo Asai