Toyota Jidosha Kabushiki Kaisha

Shinji Aso

Takao Watanabe

Junichi Matsuo

Shigeto Kajiwara

Yuji Kakeno

Tomoya Ogawa

Yutaka Tano

Akihiro Kamiya

Tatsuya Fukami

Tomonori Imamura

Tomohiro Saito

Takahiro Umehara

Naohisa Tsuchiya

Under a condition that a command to stop a fuel cell system is received and a state of charge of a secondary battery is equal to or lower than a threshold which is a value obtained by adding a first predetermined value to a lower limit at which electric power required to stop and start the fuel cell system is supplied, forced charging of the secondary battery by a fuel cell is performed until the state of charge reaches the threshold. After the forced charging is performed, in a case where the command to stop the fuel cell system is received within a predetermined period, the controller sets the threshold to a value obtained by adding a second predetermined value lower than the first predetermined value to the lower limit under the condition.

Fuel cell control device, control method thereof, and fuel cell vehicle

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

A fuel cell system includes: a fuel cell stack; a voltage sensor configured to detect voltage of the fuel cell stack; a fuel cell relay connected to the fuel cell stack; a switch connected between the fuel cell stack and the fuel cell relay; an overcurrent detector configured to detect an overcurrent flowing to the switch; and a power generation stop device configured to stop power generation of the fuel cell stack when the overcurrent detector detects the overcurrent and the detected voltage becomes a specified value or less.

Provided is a voltage control device of a fuel-cell vehicle capable of securing good acceleration responsiveness while suppressing battery deterioration even when a vehicle acceleration request is made in the situation where the output from a battery is restricted. When determining that electric power suppliable from a secondary battery to an air compressor is less than a lower limit of an acceleration maintaining-electric power of the air compressor, a voltage control device of a fuel-cell vehicle maintains a state where electric power generated by a fuel cell is consumed by an electric power drive, and supplies the electric power consumed by the electric power drive to the air compressor when a vehicle acceleration request is made.

Voltage control device for fuel-cell vehicle

A fuel cell system for a vehicle includes: a fuel cell; a plurality of loads that consumes power generated by the fuel cell and includes a vehicle driving motor; a secondary battery configured to be charged with excess power when an amount of power generated by the fuel cell is greater than an amount of power consumed by the loads and to discharge shortage power when the amount of power generated by the fuel cell is less than the amount of power consumed by the loads; and a control unit configured to control the amount of power generated by the fuel cell such that an amount of charging-discharging power of the secondary battery is maintained at a predetermined value.

Fuel cell system for vehicle and control method thereof

A fuel cell system includes a drive motor, a fuel cell, an auxiliary machine, a secondary battery, a temperature sensor, a current sensor, and a control section. The control section controls the secondary battery for discharging by driving the drive motor or the auxiliary machine and for charging through power generation by the fuel cell or regeneration by the drive motor when a temperature measured by the temperature sensor is lower than a specified value.

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.

An object of the present invention is to reduce the period of time required to stop a fuel cell system and to suppress freezing of a fuel cell. The fuel cell system includes a controller that controls operations of a fuel cell, and the controller operates the fuel cell in a dry condition according to a state quantity (e.g., impedance) of the fuel cell in operation. The controller can operate the fuel cell in a dry condition before a system stop command is issued. In addition, the controller can switch an operation of the fuel cell from a dry condition to a wet condition when a required output of the fuel cell or a vehicle speed of a vehicle equals or exceeds a predetermined value.

Even in a fuel cell system which performs scavenging processing after the power generation of a fuel cell is stopped, the operation time for when a battery is being operated can be increased. When determining that the condition of running out of gas occurs based on a sensor value of a pressure sensor, a control unit stops the power generation of the fuel cell. The control unit, for example, shortens the time required for scavenging processing and then performs the scavenging processing. On the other hand, when determining that the condition of running out of gas does not occur and when the power generation of the fuel cell should be stopped, the control unit stops the power generation and then performs normal scavenging processing.

Fuel cell system with scavenging means and control unit thereof

A fuel cell system has a flooding elimination mode as one of available operation modes of fuel cells and includes a drive controller. When the ambient temperature of the fuel cell system is not higher than a preset first temperature, the drive controller causes the fuel cells to be driven in the flooding elimination mode. When the ambient temperature of the fuel cell system is not lower than a preset second temperature that is higher than the first temperature, the drive controller prohibits the fuel cells from being driven in the flooding elimination mode. On the occasion of input of a checkup instruction of the fuel cells, the drive controller causes the fuel cells to be driven in the flooding elimination mode, independently of the ambient temperature. This arrangement effectively improves the user's convenience at the checkup time of the fuel cell system having the operation mode for eliminating the state of flooding.

A fuel cell system capable of adequately controlling the water content of a fuel cell is provided. An impedance reference value is stored in a memory for an impedance comparator. The impedance reference value is a reference value that is set in order to prevent the water content in a fuel cell from decreasing too much. The impedance comparator compares a measured impedance value supplied from an impedance operation unit with the impedance reference value and performs scavenging control based on the comparison result.

Fuel cell system for impedance measurement and scavenging processing

The present invention seeks, when a temporary abnormality occurs in a voltage converter, a recovery of the voltage converter, and minimizes the inadequacy of the drive power. In a fuel cell system comprising an electric storage device disposed with a voltage converter, in the case where an abnormality occurs in the voltage converter, the voltage converter is stopped once, an attempt is made to recover the voltage converter to a normal state after the voltage converter is stopped, and drive power is generated in at least a fuel cell until the voltage converter recovers to the normal state. It is preferred that an upper limit of the power which can be generated when the voltage converter recovers to the normal state be set to a value lower than an upper limit of power obtained prior to the occurrence of the abnormality. Further, it is preferred that the limit be canceled step by step when recovering the voltage converter to a normal state.

Fuel cell system with electric storage device and voltage converter

A fuel cell system that can continue a stable operation of a fuel cell and perform un-interrupted operation of the system even upon the occurrence of an abnormality in a voltage converter, and a mobile body. A fuel cell system where an accumulator device is connected to a load via a voltage converter in parallel with a fuel cell includes an auxiliary equipment connected nearer the fuel cell than the voltage converter, and a control device for controlling the voltage converter and the auxiliary equipment. The control device changes the operational point of the auxiliary equipment when an abnormality has occurred in the voltage converter.

Fuel cell system and mobile body

A power supply system is provided with a plurality of driving motors, a power converter, and a plurality of power supplies which supply the driving motors with power and have different output voltages. Each power supply is connected with at least one driving motor through the power converter and with at least one driving motor through a path which does not include the power converter.

Growing community of inventors

Toyota, Japan

Shinji Aso