Patent application number | Description | Published |
20090017351 | FUEL CELL SYSTEM - There is disclosed a fuel cell system capable of performing low-temperature countermeasure control at an appropriate timing when necessary. To judge necessity of the low-temperature countermeasure control, a control unit performs automatic judgment based on surrounding environment information supplied from a navigation system and indicating a state (an outside air temperature or the like) of a surrounding environment. Then, the control unit weighs both of a judgment result of this automatic judgment and a judgment result of switch judgment based on user's operation of a low-temperature countermeasure control switch, and performs final judgment based on the respective weighted judgment results. | 01-15-2009 |
20090110985 | Fuel Cell System - A fuel cell system according to the present invention is characterized by comprising a measurement unit which measures an impedance of a fuel cell in a predetermined frequency region, and a regulation unit which regulates an amount of a gas to be supplied to the fuel cell based on a measured value of the impedance in the predetermined frequency region. According to such a constitution, the impedance of the fuel cell in the predetermined frequency region (e.g., a low frequency region) is measured, and the amount of the gas (e.g., an amount of an oxidizing gas) to be supplied to the fuel cell is regulated based on this measured value of the impedance. Here, since the impedance of the fuel cell in the predetermined frequency region largely differs with a fuel supply state (see FIG. | 04-30-2009 |
20090117427 | Fuel Cell System - There is provided a fuel cell system in which a constantly accurate impedance measurement is made possible regardless of a response characteristic of the voltage converting device. A superimposed signal analysis section analyzes an impedance measuring signal after passing through a DC/DC converter to thereby notify a superimposed signal amplitude control section of an analysis result. A superimposed signal amplitude control section controls an amplitude value of the impedance measuring signal generated by a superimposed signal generating section based on the result notified from the superimposed signal analysis section. | 05-07-2009 |
20090130509 | Fuel Cell System - There is disclosed a fuel cell system in which a poisoned electrode catalyst can be recovered while meeting a demand for an output power. When a controller detects that an electrode catalyst is positioned, the controller derives a target operation point adequate for recovering a function of the poisoned electrode catalyst to realize shift of an operation point so that the output power is kept constant. Specifically, an FC voltage is controlled using a DC/DC converter, and an amount of an oxidizing gas to be fed from an oxidizing gas supply source is adjusted, thereby controlling an FC current. | 05-21-2009 |
20090148735 | Fuel Cell System - There is disclosed a fuel cell system capable of stably operating auxiliary devices driven at a high voltage and the like, even in a case where a poisoned electrode catalyst is recovered or a fuel cell is warmed up. On detecting that the electrode catalyst is poisoned, a controller derives a target operation point which is sufficient for recovering an activity of the poisoned electrode catalyst. Then, shift of the operation point from a usual operation point to a low-efficiency operation point is realized so that an output power is held to be constant. | 06-11-2009 |
20090148736 | Fuel Cell System and Mobile Object - There is disclosed a fuel cell system or the like capable of stably operating an auxiliary machine and the like, even when recovering a poisoned electrode catalyst and warming up a fuel cell. A controller derives a target operation point sufficient for recovering activity of the poisoned electrode catalyst, and realizes shift of an operation point to a target operation point in a state in which an output power is held to be constant. The operation is switched to a low-efficiency operation point, whereby an output voltage of the fuel cell lowers, but the voltage is raised to an allowable input voltage of a high-voltage auxiliary machine by a DC/DC converter. | 06-11-2009 |
20090169934 | Fuel Cell System - A fuel cell system according to the present invention is characterized by comprising a fuel cell, measurement means for measuring impedances of the fuel cell in two kinds or more of frequency regions, and first judgment means for judging two or more parameters concerned with an internal state of the fuel cell based on measurement results of the impedances in the respective frequency regions. According to such a constitution, the impedances in the two or more types of frequency regions (a high frequency region, a low frequency region and the like) are measured to judge two or more parameters such as a wet state of an electrolytic film of the fuel cell and a supply state of a fuel gas, which are concerned with the internal state of the fuel cell based on this measurement result. Since such judgment is performed, as compared with the conventional technology, the internal state of the fuel cell can accurately be grasped, and highly efficient and highly robust control of the fuel cell system can be performed. | 07-02-2009 |
20090169935 | Fuel Cell System - There is provided a fuel cell system capable of warming up a fuel cell while inhibiting generation of a rush current. A control device switches the connection/disconnection between a fuel cell and a short circuit by a shorting relay. The control device spends, before switching the shorting relay from disconnection to connection during starting at a low temperature, an oxidizing gas remaining in the cathode of the fuel cell by driving auxiliary devices to generate an oxidizing gas-deficient state. Then, the control device switches FC relays from ON to OFF and the shorting relay from OFF to ON to thereby complete the preparation for supplying a short-circuit current. | 07-02-2009 |
20090208786 | FUEL CELL SYSTEM - There is provided a fuel cell system capable of notifying a user that control for low-temperature countermeasure is performed, without any strange feeling and false recognition. When control for low-temperature countermeasure such as scavenging at system termination or warm-up at system start-up is made, the user is reliably notified that the control is performed, by a text message or a speech message. Consequently, even in a situation where the system is operating after an ignition key is turned off, the user suffers neither strange feeling nor false recognition. | 08-20-2009 |
20090269628 | FUEL CELL SYSTEM, ESTIMATION DEVICE OF AMOUNT OF ANODE GAS TO BE GENERATED AND ESTIMATION METHOD OF AMOUNT OF ANODE GAS TO BE GENERATED - There is disclosed a fuel cell system or the like capable of sufficiently reducing an exhaust hydrogen concentration even in a case where a fuel cell is operated in a state of a low power generation efficiency. A bypass valve is arranged between an oxidation gas supply path and a cathode-off gas channel. In a state in which supply of an oxidation gas to a cathode falls short, pumping hydrogen is included in a cathode-off gas. Therefore, a valve open degree of the bypass valve is regulated, and a flow rate of bypass air is regulated to control the exhaust hydrogen concentration. | 10-29-2009 |
20100013490 | FUEL CELL SYSTEM - When the operation point of a DC/DC converter, which steps up/down the output voltage of a fuel cell stack, is in a range of reduction in response capability and further there is issued a request of determining an AC impedance, a controller switches numbers of the drive phases of the DC/DC converter to determine an AC impedance of the fuel cell stack. If the operation point of the DC/DC converter is in the range of reduction in response capability and further the precision of determining the AC impedance is reduced, then the determination of AC impedance in the range of reduction in response capability is inhibited and the switching of the phases of the DC/DC converter is implemented, thereby causing the operation point of the DC/DC converter to be out of the range of reduction in response capability, with the result that the precision of determining the AC impedance can be raised. | 01-21-2010 |
20100047630 | FUEL CELL SYSTEM AND ITS OPERATION METHOD - A fuel cell system includes: a fuel cell which generates electricity; and control means which supplies an output power from the fuel cell to a predetermined load power source while realizing a low-efficiency operation of the fuel cell, thereby driving and controlling the load power source. The control means sets the output voltage of the fuel cell during the low-efficiency operation to a value not smaller than the minimum drive voltage of the load power source. | 02-25-2010 |
20100086815 | FUEL CELL SYSTEM - A fuel cell system capable of reducing time spent before actual execution of low-temperature countermeasure processing is provided. At the time of activation, a control unit for the fuel cell system refers to, for example, a detected FC temperature and judges whether or not the low-temperature countermeasure processing is necessary for the activation. If the control unit determines that the low-temperature countermeasure processing is necessary, it controls an output voltage of the fuel cell to be a target voltage for the low-temperature countermeasure processing, without having the fuel cell enter an OCV state, and then executes the low-temperature countermeasure processing. | 04-08-2010 |
20100227240 | FUEL CELL SYSTEM - The theme of the present invention is a fuel cell system capable of avoiding a disadvantage caused by the maintaining of a low-efficiency operation to improve the safety of a system operation. The fuel cell system is configured to perform the low-efficiency operation having a large power loss as compared with a usual operation at a predetermined low temperature to raise the temperature of a fuel cell in a short time as compared with the usual operation. The fuel cell system prohibits the low-efficiency operation to execute the usual operation, in a case where predetermined conditions are established at the predetermined low temperature. The predetermined conditions include a time when the generated power of the fuel cell cannot be consumed, a time when this generated power cannot be accumulated in a battery, or a time when the flooding of the fuel cell is generated. | 09-09-2010 |