Abstract: A controller of a fuel cell system, when the fuel cell system is started up and thrown into warming-up operation, sets a rotating speed of the circulation pump to a reference rotating speed, subsequently repeatedly performs: (a) a process of acquiring the first temperature and the second temperature; and (b) a process of controlling the circulation pump by setting the rotating speed of the circulation pump in order that with the first temperature is within a predetermined temperature range, the rotating speed is made generally higher than the reference rotating speed with increasing temperature difference between the first temperature and the second temperature, and when a condition for rotating the circulation pump at the reference rotating speed is satisfied, the controller sets the rotating speed of the circulation pump to the reference rotating speed.

Abstract: A controller of a fuel cell system, when the fuel cell system is started up and thrown into warming-up operation, sets a rotating speed of the circulation pump to a reference rotating speed, subsequently repeatedly performs: (a) a process of acquiring the first temperature and the second temperature; and (b) a process of controlling the circulation pump by setting the rotating speed of the circulation pump in order that with the first temperature is within a predetermined temperature range, the rotating speed is made generally higher than the reference rotating speed with increasing temperature difference between the first temperature and the second temperature, and when a condition for rotating the circulation pump at the reference rotating speed is satisfied, the controller sets the rotating speed of the circulation pump to the reference rotating speed.

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 resupplies the oxidizing gas to recover the output voltage of the fuel cell.

Abstract: Provided is a fuel cell system including a fuel cell which is a DC power source and boosting unit which boosts the output voltage of the fuel cell for supply to a load. The boosting unit has: a main boosting unit which has a switch and a coil and boosts the output voltage of the fuel cell by a back electromotive force of the coil generated by a switching operation of the switch with respect to the coil; and a sub boosting unit having a snubber capacitor which adjusts a potential difference between the both electrodes of the switch by an accumulation amount and reduces the switching loss of the switch by adjusting the accumulation amount of the snubber capacitor upon a switching operation. The electricity of the snubber capacitor discharged when reducing the accumulation amount of the snubber capacitor is made to flow into processing unit other than the fuel cell by the sub boosting unit.

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 resupplies the oxidizing gas to recover the output voltage of the fuel cell.

Abstract: Provided is a fuel cell system including a fuel cell which is a DC power source and boosting unit which boosts the output voltage of the fuel cell for supply to a load. The boosting unit has: a main boosting unit which has a switch and a coil and boosts the output voltage of the fuel cell by a back electromotive force of the coil generated by a switching operation of the switch with respect to the coil; and a sub boosting unit having a snubber capacitor which adjusts a potential difference between the both electrodes of the switch by an accumulation amount and reduces the switching loss of the switch by adjusting the accumulation amount of the snubber capacitor upon a switching operation. The electricity of the snubber capacitor discharged when reducing the accumulation amount of the snubber capacitor is made to flow into processing unit other than the fuel cell by the sub boosting unit.

Abstract: Nitrogen concentration in a fuel-cell stack is estimated more accurately, hence the life of the fuel-cell is prevented from being reduced by operation performed when the impurity concentration in the anode increases. The fuel-cell system comprises: stack temperature detection means for detecting the temperature of the fuel-cell stack; fuel electrode pressure detection means for detecting the pressure of the fuel electrode; and standing time measuring means for measuring the standing time.

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: Nitrogen concentration in a fuel-cell stack is estimated more accurately, hence the life of the fuel-cell is prevented from being reduced by operation performed when the impurity concentration in the anode increases. The fuel-cell system comprises: stack temperature detection means for detecting the temperature of the fuel-cell stack; fuel electrode pressure detection means for detecting the pressure of the fuel electrode; and standing time measuring means for measuring the standing time.

Abstract: A route guiding apparatus provides information for a route using public transportation as an alternative to a vehicular route. In addition to searching for a vehicular route from a current location to a destination, it is determined whether the current location and the destination are within a zone in which public transportation can be used. When the current location and the destination are determined to be within a public transportation zone, a route using public transportation is searched for. Subsequently, the cost of the route using public transportation and the cost of the vehicular route are compared. When the cost of the public transportation route falls within a predetermined limit, the apparatus indicates the public transportation route. The route costs are calculated considering factors such as required travel time and ticket fees. The apparatus may also recommend public transportation when no parking is available near the destination, or based on traffic information concerning the vehicular route.