Toyota Jidosha Kabushiki Kaisha

Kohei Oda

Satoshi Watanabe

Kenji Umayahara

Tomio Yamanaka

Shuya Kawahara

Hideyuki Kumei

Yuji Kakeno

Atsuo Iio

Yoshiaki Tsuruta

Naoki Sugiyama

Mitsuhiro Nada

Takahiko Hasegawa

Satoshi Shiokawa

Norihiro Fukaya

Shuhei Nakamura

A fuel cell system includes a power supply circuit that supplies electric power from a fuel cell and a secondary battery to the load and charges the secondary battery with electric power from the fuel cell. A decision value acquirer monitors a charge-discharge state of the secondary battery and obtains a decision value that is used to determine a degree of localization of an ion concentration in an electrolytic solution in the secondary battery. When the decision value becomes equal to or greater than a predetermined reference value, a controller limits discharge of the secondary battery. When the decision value is equal to or greater than the reference value and the required power decreases, the controller limits a decrease in output power of the fuel cell and causes the secondary battery to be charged with the electric power corresponding to the limitation imposed on the decrease in output power.

Fuel cell system

A fuel cell system includes a removal treatment execution unit configured to execute an oxide layer removal treatment that removes an oxide layer generated on a catalyst of a fuel cell. The removal treatment execution unit is configured to execute the oxide layer removal treatment by adjusting a voltage of the fuel cell to be within a predetermined second voltage range lower than a predetermined first voltage range that is lower than an open-circuit voltage, when an operation of the fuel cell system shifts from a first operation, where a current value of the fuel cell is zero and the flow rate is controlled to maintain the voltage of the fuel cell within the first voltage range, to a second operation, where the current value is larger than zero and the flow rate is controlled in response to an output request to the fuel cell.

Fuel cell system and oxide layer removal method

A fuel cell system according to one embodiment performs refresh control of an electrode catalyst of a fuel cell, by reducing a stack voltage as a voltage of the fuel cell to a refresh voltage at which the electrode catalyst is activated. The system includes the fuel cell that generates electric power by an electrochemical reaction using fuel gas and oxidation gas, a stack voltage sensor that sensors the stack voltage, and a controller that controls power of the fuel cell. When a high load demand that makes the stack voltage lower than a given voltage is made on the fuel cell, the controller causes the fuel cell to deliver power commensurate with the high load demand, and performs refresh control when the stack voltage becomes lower than the given voltage through the above control.

A fuel cell system of the present disclosure performs a first and a second catalyst activation process, and the first catalyst activation process is performed where a flow rate of the air supplied to the fuel cell by the air compressor is reduced to be less than that before the refresh control is performed while keeping an amount of a current drawn from the fuel cell by the fuel cell converter at the same value as that before the refresh control is performed, and the second catalyst activation process is performed where the value of the current drawn from the fuel cell by the fuel cell converter is increased to be greater than that before the refresh control is performed while keeping the flow rate of the air supplied to the fuel cell by the air compressor at the same value as that before the refresh control is performed.

A fuel cell system comprises: a fuel cell stack; a turbo compressor configured to supply a cathode gas to the fuel cell stack through a cathode gas supply line; a pressure regulation valve configured to regulate a pressure of the cathode gas; and a controller, wherein the controller is configured to calculate a target rotation speed of the turbo compressor and a target opening position of the pressure regulation valve, based on a target flow rate of the cathode gas and a target pressure of the cathode gas that are determined according to a required power output of the fuel cell stack and to control the turbo compressor and the pressure regulation valve using the calculated target rotation speed and the calculated target opening position, and the controller is configured, upon increase of the required power output, to: (a) determine an acceptable overshoot level of a flow rate of the cathode gas that is to be supplied to the fuel cell stack, the acceptable overshoot level being selected from a plurality of levels based on at least an increased amount of the required power output; and (b) set a time change in opening position of the pressure regulation valve such that an overshoot amount in a change of the flow rate of the cathode gas becomes smaller as the acceptable overshoot level gets lower, and perform control of the pressure regulation valve. This configuration suppresses an excessive overshoot in the flow rate of the cathode gas.

Fuel cell system and control method of the same

A fuel cell system comprises a controller configured to: (i) calculate a torque target value of a compressor and an opening position target value of a pressure regulation valve from a flow rate target value of a cathode gas and a pressure target value of a cathode gas flow path, the flow rate target value of the cathode gas and the pressure target value being determined according to a required power output of a fuel cell stack; (ii) calculate a torque feedback value of the compressor from a difference between a flow rate measurement value and the flow rate target value of the cathode gas, and control the compressor using a torque command value obtained by adding the torque target value and the torque feedback value; and (iii) calculate an opening position feedback value of the pressure regulation valve from a difference between a pressure measurement value and the pressure target value of the cathode gas flow path, and control an opening position of the pressure regulation valve using an opening position command value obtained by adding the opening position target value of the pressure regulation valve and a delayed opening position feedback value that is obtained by delaying the opening position feedback value. This configuration suppresses the hunting of the flow rate and the pressure.

A fuel cell system includes an air compressor that supplies oxidant gas to a fuel cell installed in a fuel cell vehicle, a measured rotational speed acquirer that acquires a measured value of rotational speed of the air compressor, and a controller that calculates a rotational speed command value of the air compressor based on required generated power of the fuel cell, calculates a torque command value of the air compressor based on the calculated rotational speed command value and current rotational speed of the air compressor, and controls rotational speed of the air compressor based on the calculated torque command value. The controller estimates the current rotational speed of the air compressor baaed on the measured value of the rotational speed acquired by the measured rotational speed acquirer and a history of the calculated torque command value, and calculates the torque command value by using the estimated rotational speed.

Fuel cell system and method for controlling rotational speed of air compressor

In a vehicle including a fuel cell system, an electronic control unit is configured to perform first processing in which a rotation speed of an air pump is controlled based on a torque command value and a rotation speed command value, and to perform, in the first processing, at least one of second processing in which the torque command value is set to be larger than the calculated torque command value when at least one of values of an accelerator position, required electric power, and the rotation speed command value or a change rate thereof is increased by a prescribed first value or more, and third processing in which the torque command value is set to be smaller than the calculated torque command value when at least one of the values or the change rate thereof is decreased by a prescribed second value or more.

Vehicle including fuel cell system

With a fuel cell vehicle includes a fuel cell and a secondary battery, a drive motor and a pump motor are connected to each other via an electric power line so that the drive motor and the pump motor are capable of receiving and supplying electric power with each other without involving reception and supply of electric power with the secondary battery. The control device determines an upper-limit guard value of torque of the pump motor based on a dischargeable power of the secondary battery and an output power of the fuel cell, or determines a lower-limit guard value of torque of the pump motor based on a chargeable power of the secondary battery and an output power of the fuel cell.

Fuel cell vehicle and control method therefor

A vehicle including a secondary battery includes an electricity generation device; an amount-of-stored electricity detection portion; an inverter that converts electric power output from the secondary battery into alternating-current power; an external load connection portion that connects an external load to the secondary battery via the inverter; and a control portion () that controls charging/discharging of the secondary battery. The control portion causes the electricity generation device to charge the secondary battery based on a value detected by the amount-of-stored electricity detection portion such that the amount of electricity stored in the secondary battery is in a predetermined range, and the control portion performs a control such that when the electric power is supplied to the external load during stoppage of the vehicle, an upper limit value of the amount of stored electricity is different from the upper limit value during traveling of the vehicle.

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Toyota, Japan

Kohei Oda