| Patent application number | Description | Published |
| 20100248054 | FUEL CELL SYSTEM - Electric power generation is properly controlled during a high potential avoidance operation. A fuel cell system comprises a fuel cell for generating an electric power upon receiving supply of a reactant gas and a controller for performing control for high potential avoidance with the upper limit of the output voltage of the fuel cell as a high potential avoidance voltage lower than the open end voltage thereof. The controller computes a larger system requirement power out of a system requirement power calculated from a load requirement and a system requirement power calculated from the high potential avoidance voltage as a system requirement power for the fuel cell. To compute the system requirement power for the fuel cell, not only the system requirement power calculated from the load requirement but also the system requirement power calculated from the high potential avoidance voltage are taken into account, and therefore the electric power can be stably generated without causing fuel shortage. The amount of the electric power to be generated can be properly controlled, and hence battery overcharging can be thus prevented. | 09-30-2010 |
| 20100273071 | FUEL CELL SYSTEM AND FUEL CELL DEGRADATION JUDGMENT METHOD - Provided is a fuel cell system which can measure an air blow interval and consider an exceptional condition such as a high-potential-avoiding operation, thereby enabling an accurate judgment of degradation of an electrolyte. An actual air blow time interval is measured while estimating a theoretical air blow time interval when an increase of a hydrogen consumption amount corresponding to a cell voltage in the high-potential-avoiding operation according to an output current by using a relationship table which contains a record of a relationship between a hydrogen consumption amount consumed for maintaining the function of a fuel cell and the air supply time interval varying with the increase of the hydrogen consumption amount. The degradation of the electrolyte of the fuel cell is judged according to whether the measured actual air blow time interval is shorter than the theoretical air blow time interval corresponding to the hydrogen consumption amount. | 10-28-2010 |
| 20110018491 | POWER SUPPLY CONTROL CIRCUIT - In order to more rapidly warm up a battery device in a power supply equipped with a fuel cell and a battery device, a fuel-cell-mounted vehicle driving system for driving and controlling a rotating electric machine installed on a vehicle comprises an inverter connected to the rotating electric machine; a power supply circuit having a battery device, a voltage converter, and a fuel cell; and a power supply control device for controlling the power supply circuit. The power supply control device includes an FC output voltage setting module for setting the output voltage of the fuel cell, an OCV avoidance module for, when an FC output voltage is set, avoiding a voltage around an OCV, a battery warm-up control determination module for determining whether the battery device is under warm-up control or not, and an OCV avoidance release module for, when the battery device is under the warm-up control, releasing the OCV avoidance. | 01-27-2011 |
| 20110033762 | FUEL BATTERY SYSTEM - A fuel battery system which can suppress unexpected variation of a target power during execution of a high potential avoidance control operation. The fuel battery system sets a high potential avoidance target voltage value, converts the high potential avoidance target voltage value into a target power value on the basis of the voltage-power property map of a fuel battery, limits the target power value within a range between a predetermined upper limit value and a predetermined lower limit value, and controls the operation of the fuel battery on the basis of the target power value while limiting the output voltage of the fuel battery to a value which is not larger than the high potential avoidance target voltage. This can suppress the unexpected variation of the target power value resulting from the erroneous estimation of output properties caused by the momentary drop of the high potential avoidance target voltage. | 02-10-2011 |
| 20120007545 | FUEL CELL SYSTEM, CONTROL METHOD FOR THE FUEL CELL SYSTEM, AND VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - A fuel cell system includes a fuel cell, a secondary cell, and a control portion that controls the amount of electricity generated when the fuel cell is started. A start-time target voltage is set so as to avoid the overcharged state of the secondary cell. A voltage adjustment portion that adjusts the output voltage of the fuel cell between an open-circuit voltage and a high-potential-avoiding voltage adjusts the amount of electricity generated at the time of starting the fuel cell, on the basis of the start-time target voltage. | 01-12-2012 |
| 20120013183 | FUEL CELL SYSTEM, CONTROL METHOD FOR THE FUEL CELL SYSTEM, AND ELECTRIC VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - A fuel cell system includes: a secondary cell; a voltage converter provided between the secondary cell and a load; a fuel cell; an FC relay that turns on and off electrical connection between the fuel cell and the shared electrical path; an electrical-leakage detector that detects electrical leakage in an electrical system; and a control portion that performs determination regarding electrical leakage. The control portion has: start means for starting the fuel cell by raising voltage of the fuel cell from a starting voltage to an operation voltage that is lower than an open-circuit voltage; and electrical leakage determination means for performing the determination regarding electrical leakage after a predetermined time elapses, when the FC relay is closed while a voltage difference between the voltage of the fuel cell and voltage supplied from the voltage converter to the load is greater than a predetermined threshold value. | 01-19-2012 |
| 20120013289 | FUEL CELL SYSTEM, AND ELECTRIC VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - A fuel cell system starts a fuel cell by setting the voltage supplied to a secondary cell from a voltage transformer at an open-circuit voltage of the fuel cell, and raising the voltage of the fuel cell from a starting voltage to the open-circuit voltage, in the case where the secondary cell is expected to be overcharged if the secondary cell receives electric power. In the case where the secondary cell is not expected to be overcharged if the secondary cell receives electric power, the system starts the fuel cell by setting the voltage supplied from the voltage transformer at a high-potential-avoiding voltage that is lower than the open-circuit voltage of the fuel cell at or after the elapse of a predetermined time following the output of a command to close an FC relay, and raising the voltage of the fuel cell from the starting voltage to the high-potential-avoiding voltage. | 01-19-2012 |
| 20120015267 | FUEL CELL SYSTEM, CONTROL METHOD FOR THE FUEL CELL SYSTEM, AND ELECTRIC VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - A fuel cell system includes a fuel cell that has a plurality of fuel unit cells, and a control portion that controls voltage of the fuel cell. The control portion has: start means for starting the fuel cell by raising the voltage of the fuel cell from a starting voltage to a high-potential-avoiding voltage that is lower than an open-circuit voltage; and command means for further raising the voltage of the fuel cell beyond the high-potential-avoiding voltage if cell voltage of at least one of the plurality of fuel unit cells is lower than or equal to a certain voltage after a certain time elapses after the voltage of the fuel cell is raised to the high-potential-avoiding voltage. | 01-19-2012 |
| 20120015268 | FUEL CELL SYSTEM, CONTROL METHOD FOR THE FUEL CELL SYSTEM, AND ELECTRIC VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - A fuel cell system that includes a fuel cell that generates electricity through an electrochemical reaction between a fuel gas and an oxidant gas, and a control portion that determines whether there is leakage of the fuel gas. The control portion has start means for starting the fuel cell by raising the voltage of the fuel cell from a starting voltage to an operation voltage that is lower than an open-circuit voltage, and leakage determination means for determining whether there is leakage of the fuel gas before the voltage of the fuel cell reaches the operation voltage when the fuel cell is started. | 01-19-2012 |