Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Shigeto Kajiwara

Shinji Aso

Katsuki Ishigaki

Tomonori Imamura

Tadaichi Matsumoto

Mitsuhiro Nada

Kyo Hattori

Masaaki Yamaoka

Tetsuya Bono

Hiroaki Mori

Hiromi Tanaka

Masahiro Shige

Hideki Kashiwagi

Yoshimasa Negishi

Naohisa Tsuchiya

Kazumasa Takada

Hiroshi Nakayama

Keiichi Toriumi

Tomohiro Saitou

A fuel cell system includes a plurality of electrical components that are supplied with electric power generated by a fuel cell, a refrigerant circuit that cools the fuel cell using a refrigerant, a tank that is connected to the refrigerant circuit, stores the refrigerant, and is replenished with the refrigerant, a detecting unit that detects an insulation resistance value of the fuel cell system, and an identification unit that identifies at what position of the fuel cell system the insulation resistance value has decreased when it is detected that the insulation resistance value has decreased. The detecting unit performs a process of determining whether the decrease in insulation resistance value is temporary when the identified position is the fuel cell and determines that there is no failure requiring repair when the decrease in insulation resistance value is temporary.

Fuel cell system

An object is to allow for the move of a vehicle even in the event of an abnormality in a lid sensor. A control method of a vehicle with a fuel cell mounted thereon comprises: (a) if a signal of a lid sensor that is configured to detect opening and closing of a lid door for a gas filler port of the vehicle indicates that the lid door is open, then prohibiting move of the vehicle; and (b) if it is judged that the lid sensor has a defect or if a predetermined special operation is performed, then eliminating prohibition of the move of the vehicle despite that the signal of the lid sensor indicates that the lid door is open.

Vehicle with fuel cells mounted thereon and control method of the vehicle

A fuel cell system () includes: a motor (); a fuel cell () and an electrical storage device () connected to the motor () in parallel with each other; a first voltage converter () between the motor () and the fuel cell (); a second voltage converter () between the motor () and the electrical storage device (); a load circuit between the motor () and both the first () and second () voltage converters; and a control unit (). The control unit () stops boost operation of the first voltage converter () when conditions VFC&#x3e;VM_min and VFC&#x3e;VBAT+a whereas the control unit () prohibits a stop of the boost operation of the first voltage converter () when the conditions are not satisfied, wherein in the conditions, VFC is a fuel cell terminal voltage, VBAT is an electrical storage device terminal voltage and VM_min is a load circuit input terminal voltage, set to minimize a system loss while ensuring a torque required of the motor ().

Fuel cell system and control method therefor

A gas detection system functions to detect a specific gas present in a certain space. The gas detection system includes a gas concentration detector arranged to detect concentration of the specific gas as a gas concentration. The gas detection system also has a determination module configured to determine whether the gas concentration detected by the gas concentration detector exceeds a set threshold value. In response to input of a checking instruction for checking up the gas concentration detector into the determination module, the determination module uses a threshold value for checkup purpose, in place of the set threshold value. This arrangement effectively enhances the convenience in the process of checking up the gas concentration detector.

Gas detection system, vehicle, and checkup method for gas detection system

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.

A gas detection system is configured to detect a preset gas in a predetermined space. The gas detection system includes a gas concentration detector constructed to detect a gas concentration of the preset gas, a recording assembly, a notification module, and a decision module. When the gas concentration detected by the gas concentration detector is higher than a preset first reference value, the decision module controls the notification module to give notice. When the detected gas concentration is higher than a preset second reference value but is lower than the preset first reference value, on the other hand, the decision module controls the notification module to give no notice but record a specific piece of information into the recording assembly. This arrangement of the gas detection system enables the user to readily detect deterioration of a device utilizing a fuel, for example, fuel cells.

Gas detection system, fuel cell system, and vehicle

In a fuel cell system, it is possible to suppress fixation of a fluid circulating device arranged in a fluid passage connected to a fuel cell main body. The fuel cell system is provided with a fuel cell stack, a system main body having respective elements for supplying a fuel gas and respective elements for supplying an oxidizing gas, and a control device. The control device includes a fluid circulating device drive processing unit having a function to forcibly drive the fluid circulating device after determining, based on a judgment related to one or more of a non-use time, an operation state of the system main body, a membrane impedance state of a fuel cell, a temperature of the fuel cell stack, and a background noise, whether or not forced driving to suppress sticking of the fluid circulating device is preferable at that time.

A fuel cell system includes a fuel cell stack for receiving a supplied reactant gas to generate a power; an air compressor for removing moisture remaining in the fuel cell stack during the stop of the power generation; a secondary cell for supplying an operative power to the air compressor; and a controller for controlling the balance of water flowing into and out of the fuel cell stack so that a time required to remove the moisture remaining in the fuel cell stack by the air compressor is substantially constant.

A fuel cell system comprises a fuel cell, a reactant gas supply device, and a capacitor which supplies a power to various devices when the fuel cell is in a temporary power generation stop state. The fuel cell system drives the reactant gas supply device based on a predetermined current instruction value to supply a reactant gas to the fuel cell, thereby generating the power. Such a fuel cell system comprises a control device which judges whether or not the current instruction value is below a water balance zero current value when the water content of the fuel cell is below a predetermined threshold and the stored electric charge of the capacitor is a predetermined threshold or more. If affirmative judgment is obtained, the control device switches the power generation state of the fuel cell to the temporary power generation stop state.

Fuel cell system and control method of the system

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.

Provided is a fuel cell system which can accurately detect the water state of a fuel cell to appropriately control the water content of the fuel cell. Based on an FC outlet temperature detected by a temperature sensor, an FC outlet temperature change speed detection unit detects an FC outlet temperature change speed for a unit time. If the FC outlet temperature change speed detection unit judges that the detected FC outlet temperature change speed is lower than a change speed reference value stored in a memory, an impedance measurement instruction is transmitted to an impedance calculation unit. On receiving the impedance measurement instruction from the FC outlet temperature change speed detection unit, the impedance calculation unit performs the impedance measurement for the second time. In consequence, it is possible to realize such scavenging control as to keep the water content of a fuel cell at an appropriate level by the minimum number of impedance measurement times (e.g., twice).

A fuel cell system includes a power supply controller. In response to input of a first command prior to a start of fuel cells in a state of power supply from a power source to fuel cell-related auxiliary machinery, the power supply controller reduces an amount of electric power supplied to the fuel cell-related auxiliary machinery until input of a start instruction to start the fuel cells. In response to input of a second command, the power supply controller instructs to continue the power supply from the power source to the fuel cell-related auxiliary machinery without reducing the electric power level of the power supply, irrespective of the input or non-input of the first command. The fuel cell system of this arrangement effectively reduces the amount of electric power consumed by an electricity storage device before a start of the fuel cells.

A fuel cell system includes: a fuel cell stack for generating electric power by receiving supply of a reaction gas; an air compressor for scavenging water remaining in the fuel cell stack when power generation is stopped; a rechargeable battery for supplying electric power to the air compressor for operation thereof; and a controller for estimating an amount of water remaining in the fuel cell stack based on an alternating-current impedance of the fuel cell stack, estimating a target SOC for charging the rechargeable battery with electric power required for scavenging the amount of water, and controlling charge and discharge so that an SOC of the rechargeable battery agrees with the target SOC.

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

There is disclosed a fuel cell system capable of appropriately performing the impedance measurement and scavenging control of a fuel cell during the stop of the fuel cell system. According to the present embodiment, in the fuel cell system including a control section which monitors and controls the state of a fuel cell, the control section stops the supply of a fuel gas to the fuel cell, then executes scavenging process to discharge, from the system, a water content in the fuel cell, and intermittently measures the impedance of the fuel cell during the scavenging process of the fuel cell, and the control section is characterized in that the fuel gas is intermittently supplied to the fuel cell during the scavenging process of the fuel cell.

Growing community of inventors

Okazaki, Japan

Shigeto Kajiwara