Toyota Jidosha Kabushiki Kaisha

Yuji Kakeno

Kenji Umayahara

Mitsuhiro Nada

Yutaka Tano

Shinji Aso

Yusuke Nishida

Kohei Oda

Yoshiaki Naganuma

Michio Yoshida

Masashi Toida

Tomoya Ogawa

Takao Watanabe

Hideaki Mizuno

Hiromitsu Kawamori

A fuel cell system to be mounted on a vehicle includes: a fuel cell for generating electric power by using reactant gas; a secondary battery capable of charging and discharging electric power; a converter electrically connected between a drive motor for driving the vehicle and the secondary battery to perform voltage conversion between the drive motor and the secondary battery; and a controller for controlling the fuel cell system. The controller exerts such control that when an accelerator for accepting a speed control instruction for the vehicle has accepted a deceleration instruction under a condition that a charge rate of the secondary battery is equal to or more than a preset value, or when the accelerator has accepted a deceleration instruction under a condition that a chargeable electric power of the secondary battery is equal to or less than a preset value, electric power is discharged from the secondary battery during a period of power-running operation lasting until the drive motor with its torque being decreased shifts to regenerative operation. Thus, increases in frequency at which the auxiliary machine is operated to consume regenerative power can be suppressed.

Fuel cell system

A fuel cell system including: a fuel cell; a voltage sensor that measures output voltage of the fuel cell; a converter that boosts the output voltage; and a control unit that controls the converter using a duty ratio including a feedforward term and a feedback term, the feedforward term being set to perform feedforward control, the feedback term being set to perform feedback control, wherein when the control unit causes the converter to boost the output voltage, and when the feedforward term calculated by specified Expression I exceeds an upper limit calculated by specified Expression II, the control unit causes the converter to boost the voltage output from the fuel cell with the duty ratio including the upper limit and the feedback term.

Fuel cell system including converter boosting output voltage based on duty ratio

There is provided a fuel cell system. When receiving an instruction to start power generation of the fuel cell system, the fuel cell system is configured: (i) to obtain an output limit value of a secondary battery according to a predetermined relationship of a temperature of the secondary battery to the output limit value of the secondary battery by using the temperature of the secondary battery; (ii) to control a battery converter such as to increase a voltage of a smoothing capacitor for boosting included in the battery converter to a start-time target voltage that is higher than an open circuit voltage of a fuel cell, such that an output power of the secondary battery does not exceed the output limit value; and (iii) to operate the compressor such as to start supplying the cathode gas by the cathode gas supply system and to open the main stop valve such as to start supplying the anode gas by the anode gas supply system.

Fuel cell system and control method of the same

There is provided a fuel cell system. This fuel cell system comprises a fuel cell configured to generate electric power using reactive gases; a voltage sensor configured to measure a voltage output from the fuel cell; a converter configured to boost an input voltage that is input from the fuel cell; and a controller configured to control the converter. In the case where the voltage output from the fuel cell to the converter is to be boosted after a changeover of an operating state of the fuel cell system from an intermittent operation to an ordinary operation, when a duty ratio D1 calculated by Mathematical Formula I is greater than a duty ratio D2 calculated by Mathematical Formula II, the controller causes the converter to boost the voltage output from the fuel cell at the duty ratio D2. where VH (V) denotes a value of output voltage that is output from the converter, and Vltrg (V) denotes an estimated value of voltage that is output from the fuel cell, where Vl (V) denotes a measured value of voltage of the fuel cell by the voltage sensor, Vlmrg (V) denotes a correction amount of the measured value Vl, and Vhul (V) denotes a predetermined upper limit value of the output voltage. This configuration prevents the converter from excessively boosting the actual voltage input from the fuel cell and outputting the excessively boosted voltage.

A fuel cell system installed in a vehicle includes a fuel cell that supplies power to a motor that drives the vehicle, a pump that supplies oxygen to the fuel cell, an accelerator position detector that detects an accelerator depression amount of the vehicle, and a controller that calculates required generated power of the fuel cell and required driving power of the pump, based on the accelerator depression amount. When a preset condition of causing a sharp drop in the calculated required generated power is satisfied, the controller calculates the required driving power in such a manner that a drop rate of the required driving power becomes higher than a drop rate of the calculated required generated power, sets a lower limit to the calculated required driving power, and drives the pump in accordance with the lower limit when the required driving power is lower than the lower limit.

Fuel cell system, fuel cell vehicle, and method for controlling fuel cell system

A fuel cell system mounted in a vehicle includes a fuel cell supplying electric power to a motor driving the vehicle, a pump supplying oxygen to the fuel cell, an accelerator position detection unit detecting an accelerator depression amount of the vehicle, and a control unit calculating electric power required to be generated by the fuel cell and electric power required for driving of the pump based on the accelerator depression amount and controlling the pump based on the electric power required for the driving, in which the control unit calculates the electric power required for the driving such that a rate of increase in the electric power required for the driving exceeds a rate of increase in the electric power required to be generated when the calculated electric power required to be generated increases.

Fuel cell system, fuel cell vehicle, and control method for fuel cell system

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

A fuel cell system to be installed on a vehicle includes a fuel cell, a secondary battery, an SOC detector that detects a temperature and a state of charge of the secondary battery, an accelerator position detector that detects an accelerator depressed amount, and a controller that controls power to be generated by the fuel cell. The controller includes: a required generation power calculator that calculates required generation power based on the accelerator depressed amount and the temperature and the state of charge of the secondary battery; and a maximum required power calculator that calculates maximum required power based on the accelerator depressed amount and the temperature and the state of charge of the secondary battery. The maximum required power includes allowable charging power correlated with a maximum value of charging power. If determining that a condition for rapid reduction in consumption power of a motor is satisfied, the controller sets the allowable charging power to zero and calculates the maximum required power. If the required generation power exceeds the maximum required power, the controller makes the fuel cell generate power responsive to the maximum required power.

Fuel cell system, fuel cell vehicle, and method of controlling 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

If a required voltage which corresponds to a required power has reached a boundary voltage, which is an oxidation-reduction potential of platinum, which constitutes a catalyst of a fuel cell, the fuel cell system performs crossover-avoidance control that holds an FC instruction voltage for the fuel cell at the boundary voltage, and absorbs the gap between the required voltage and the FC instruction voltage by using a secondary battery.

During an intermittent operation of the fuel cell, a demanded FC voltage calculation portion calculates a predetermined voltage that is below a heightened potential avoidance threshold voltage as a demanded FC voltage, and outputs the voltage to a converter. When during the intermittent operation of the fuel cell, a deviation obtained by subtracting a generated power of the fuel cell from a system's allowable power that is allowable in the fuel cell system becomes less than or equal to a value 0, the demanded FC voltage correction portion corrects a command value provided for the converter so that the deviation becomes equal to the value 0.

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Nisshin, Japan

Yuji Kakeno