Abstract: 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.

Abstract: A fuel cell system is provided which can accurately detect an insulation resistance even during a high-potential prevention control. The fuel cell system includes: a fuel cell that generates electric power through an electrochemical reaction between a fuel gas and an oxidant gas; an insulation resistance measurement unit that measures an insulation resistance between the fuel cell and an outer conductor; and a control unit that controls a power generation state of the fuel cell, and the control unit carries out a high-potential prevention control that avoids a voltage of the fuel cell becoming equal to or higher than a predetermined high-potential prevention voltage threshold lower than an open circuit voltage of the fuel cell, and changes the high-potential prevention voltage threshold during an insulation resistance detection performed by the insulation resistance measurement unit.

Abstract: A fuel cell system is provided which can extend the time during which a high-potential avoidance control is performed as much as possible, thereby reducing deterioration of a fuel cell. The fuel cell system includes: a fuel cell that generates electric power upon a supply of a reaction gas; a power storage device that is charged with at least a part of power generated by the fuel cell; and a controller that controls an output voltage of the fuel cell with, as an upper limit, a high-potential avoidance voltage lower than an open end voltage thereof. The controller variably sets the high-potential avoidance voltage in accordance with the amount of charge SOC of the power storage device.

Abstract: 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.

Abstract: In a drive control system for a fuel cell-equipped vehicle including a rotating electrical machine, a control unit includes a rapid warm-up processing module for performing rapid warm-up by the low-efficiency power generation of a fuel cell, a torque command value limiting module 68 for limiting the torque command value in accordance with the change of a system voltage caused by rapid warm-up processing, and an FC output command value calculating module for calculating the output command value of the fuel cell in accordance with the limited torque command value. In a storage device connected to the control unit, a system voltage characteristic map which shows the torque-rotation speed characteristics of the rotating electrical machine corresponding to the system voltage is stored.

Abstract: There is provided a fuel cell system capable of suppressing the increase of a control error of a motor. The system includes a fuel cell which generates a power by an electrochemical reaction between a fuel gas and an oxidizing gas, a motor driven by the generated power of the fuel cell, and a control unit which controls the generation state of the fuel cell. The control unit performs high-potential avoiding control to prevent the total voltage of the fuel cell from exceeding a predetermined high-potential avoiding voltage threshold value. In a vehicle velocity region where the control switching of the traction motor is caused, the high-potential avoiding volume is inhibited.

Abstract: The oxidizing gas supply is stopped during the catalyst activation treatment, and the output voltage of the fuel cell is linearly decreased toward the reduction target voltage. Once the interruption condition of the activation treatment has been satisfied, a voltage command value of the converter is returned to a standby voltage and, after waiting till the output voltage of the fuel cell returns to the vicinity of the standby voltage, the compressor is operated to start the supply of the oxidizing gas, and the catalyst activation treatment is completed. As a result, overcharging of the battery caused by rapid increase in the output power of the fuel cell is avoided.

Abstract: A hydraulic control unit provided with oil pumps includes a first oil discharging outlet and a second oil discharging outlet, a high pressure route connected with the first oil discharging outlet, a medium pressure route with an oil pressure therein being lower than that in the high pressure route, a low pressure route with an oil pressure therein being lower than that in the medium pressure route, and a connection mode switching mechanism for selectively connecting a second oil discharging outlet with the high pressure route, the medium pressure route or the low pressure route. The connection mode switching mechanism includes a changeover valve selectively connecting the second oil discharging outlet with the medium pressure route or the low pressure route; and a changeover valve controlling device connecting the second oil discharging outlet with any of the medium pressure route and the low pressure route. The hydraulic control unit can minimize drive loss of an oil pump.

Abstract: When a request power for a fuel cell is smaller than a predetermined value, a fuel cell system stops the supply of an oxidizing gas to the fuel cell and lowers the output voltage of the fuel cell from a use upper limit voltage to a reduction voltage to perform catalyst activation processing. When the output voltage of the fuel cell lowers to an air blow voltage because of the shortage of the oxidizing gas, the fuel cell system re-supplies the oxidizing gas to recover the output voltage of the fuel cell.

Abstract: To provide a fuel cell system capable of efficiently transmitting electric power output from a battery to a load. A control unit 80 turns a relay 20 off so as to cut off the connection between a fuel cell 40 and an inverter 50 if it is determined that a command indicating that an EV travel mode should be set has been received. Then, the control unit 80 detects an output voltage of the battery 60 on the basis of SOC information supplied from a SOC sensor 65. Further, based on the detected output voltage of the battery 60, the control unit 80 determines an optimum operating voltage at the point of time by taking converter efficiency and inverter efficiency into account.

Abstract: When an output voltage of a fuel cell is lowered to carry out a catalyst activation process so as to activate a catalyst during an intermittent operation of the fuel cell, if generated power P1 exceeds allowed battery charge power, while generated power P2 does not exceed the allowed battery charge power, then low speed corresponding to the generated power P2 is selected and the output voltage of the fuel cell is decreased toward a target voltage on the basis of the low speed, which has been selected, thereby restraining sudden generation of surplus power caused by a reduction in the output voltage of the fuel cell. By the control described above, a voltage reduction speed of a fuel cell is determined according to a receiving capability of an object which receives surplus power generated by the fuel cell during the catalyst activation process of the fuel cell.

Abstract: To provide a fuel cell system that can both improve power generation efficiency of a fuel cell and maintain durability of the fuel cell. A fuel cell system performs control such that when a power requirement for the fuel cell is lower than a predetermined value, a supply of a reaction gas to a fuel cell is stopped to keep an output voltage from the fuel cell equal to a high-potential avoidance voltage that is lower than an open end voltage. The fuel cell system further controls the output voltage from the fuel cell with the high-potential avoidance voltage set to be an upper limit when the power requirement for the fuel cell is equal to or higher than a predetermined value. By setting the upper limit of the output voltage of the fuel cell to be the high-potential avoidance voltage, which is lower than the open end voltage, the catalyst can be inhibited from being degraded by an increase in the output voltage from the fuel cell up to the open end voltage.

Abstract: The problems can be solved by ensuring that Ga?Gb<Gc or Ga<Gb?Gc, wherein Ga denotes a clearing between the bore on the portion from the compression chamber of the high pressure pump to the cylindrical groove and the plunger, where a transverse aperture is connected with the bore through a cylindrical groove provided halfway through the bore of a cylinder; Gb a clearance closer to the cylindrical groove, out of the clearances between the bore from the cylindrical groove to the drive source side and the plunger; and Gc a clearance closer to the drive source side, out of the clearances between the bore from the cylindrical groove to the drive source side and the plunger.

Abstract: A hydraulic control unit (18), for a power transmission system having an oil receiving device (26,37), which controls a power transmitting condition of the power transmission system, and an oil reserving device for feeding the oil to the oil receiving device, wherein the oil reserving device comprises a piston (59) in which a diametrically large portion and a diametrically small portion are arranged integrally and coaxially, a first hydraulic chamber (57) in which the diametrically large portion, and a second hydraulic chamber (58) in which the diametrically small portion are housed liquid-tightly and movably back and forth; and an oil feeding amount control device for feeding the oil of the first hydraulic chamber to the oil receiving device, by raising the oil pressure in the second hydraulic chamber (58) to operate the piston (59).

Abstract: A block is disclosed which comprises an upper frame portion and a lower leg portion that are integrally formed under the condition that the leg portion fits into the frame portion. The frame portion can be fitted to the bottom portion of a PET bottle and removed from it, the periphery of the frame portion being provided with coupling means that couple together adjacent blocks. The leg portion includes at a center portion thereof a receiving hole into and from which the top portion of a PET bottle is fitted and from which it is removed, the outside of the receiving hole being provided with gaps within which are sandwiched corresponding peripheral walls of the frame portions coupled together by the coupling means.

Abstract: The problems can be solved by ensuring that Ga≦Gb<Gc or Ga<Gb≦Gc, wherein Ga denotes a clearing between the bore on the portion from the compression chamber of the high pressure pump to the cylindrical groove and the plunger, where a transverse aperture is connected with the bore through a cylindrical groove provided halfway through the bore of a cylinder; Gb a clearance closer to the cylindrical groove, out of the clearances between the bore from the cylindrical groove to the drive source side and the plunger; and Gc a clearance closer to the drive source side, out of the clearances between the bore from the cylindrical groove to the drive source side and the plunger.

Abstract: A video camera comprises a grip part for holding a camera body, and a mechanism part having a tape path forming part which forms a predetermined tape path for a magnetic tape. The mechanism part has a tape path forming plane approximately in parallel to a plane orthogonally intersecting the longitudinal direction of the grip part. The video camera further comprises two trigger switches for starting or stopping recording video information, and a zoom switch for varying the zoom ratio of a lens. The two trigger switches are positioned to be operable with the camera holding hand in a first camera holding posture and in a second camera holding posture, respectively. The zoom switch is positioned to be operable with the camera holding hand both in the first camera holding posture and in the second camera holding posture.

Abstract: A video camera comprises a grip part for holding a camera body, and a mechanism part having a tape path forming part which forms a predetermined tape path for a magnetic tape. The mechanism part has a tape path forming plane approximately in parallel to a plane orthogonally intersecting the longitudinal direction of the grip part. The video camera further comprises two trigger switches for starting or stopping recording video information, and a zoom switch for varying the zoom ratio of a lens. The two trigger switches are positioned to be operable with the camera holding hand in a first camera holding posture and in a second camera holding posture, respectively. The zoom switch is positioned to be operable with the camera holding hand both in the first camera holding posture and in the second camera holding posture.

Abstract: When an error is found in a program of the microcomputer, there are stored in a writable memory change address data of an address of a wrong instruction to be subjected to modification or insertion in the read-only memory, change instruction codes of modification or insertion for replacement of the wrong instruction, and a control code controlling a second program counter. When the contents of the program counter match the change address data stored in the writable memory, the program data in the writable memory is executed in place of the wrong instruction in the read-only memory according to the control code controlling the second program counter. Consequently, even when a bug is found in the program, a program replacement and/or insertion can be easily achieved and it is unnecessary to discard the final product on which the program is developed through a mask. Moreover, the program can be easily changed from an external device.