Abstract: 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.

Abstract: A current balancing apparatus includes a power supply unit 10 to output an alternating current and a plurality of series circuits connected to an output of the power supply unit. Each of the series circuits has at least one winding N1 (S1) and a voltage multiplier rectifier having rectifiers D1 and D11 (D2 and D12) and capacitors C1 and C11 (C2 and C12). Outputs of the voltage multiplier rectifiers are connected to loads LD1 and LD2, respectively. Each of the loads has loads LED1a to LED1e (LED2a to LED2e). Currents passing through the loads are balanced by electromagnetic force occurring on the at least one winding.

Abstract: 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.

Abstract: Even in a fuel cell system which performs scavenging processing after the power generation of a fuel cell is stopped, the operation time for when a battery is being operated can be increased. When determining that the condition of running out of gas occurs based on a sensor value of a pressure sensor, a control unit stops the power generation of the fuel cell. The control unit, for example, shortens the time required for scavenging processing and then performs the scavenging processing. On the other hand, when determining that the condition of running out of gas does not occur and when the power generation of the fuel cell should be stopped, the control unit stops the power generation and then performs normal scavenging processing.

Abstract: 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.

Abstract: A current balancing device includes: a power supply that outputs sinusoidal alternating-current; and a plurality of series circuits, each of the series circuits including a full-wave rectifier, one or more of windings, and one or more of loads in series connection, the full-wave rectifier connected to an output of the power supply and performing full-wave rectification for the alternating-current of the power supply. Currents flowing in the respective series circuits are balanced based on an electromagnetic force generated in one or more of the windings.

Abstract: A fuel cell system has a fuel cell stack generating electricity with a reactive gas supplied thereto and a controller supplying to the fuel cell stack the reactive gas whose pressure is higher than a normal operational pressure on condition that a temperature of the fuel cell stack is equal to or less than a predetermined threshold temperature and that a moisture content of the fuel cell stack is equal to or less than a predetermined threshold value. Where a supply pressure of the reactive gas is raised, an amount of moisture taken away by the reactive gas becomes less, and thus, water balance within the fuel cell stack shifts toward accumulation of moisture contained in the reactive gas into the film-electrode joined body. However, since the moisture content of the fuel cell stack is equal to or less than the predetermined threshold value, the system can improve the starting performance of the fuel cell stack at low temperature while suppressing flooding.

Abstract: A DC converter includes: a transformer (T1) including a primary winding (P1) and a secondary winding (S1); a series resonant circuit in which a current resonant reactor (Lr), the primary winding (P1) of the transformer, and a current resonant capacitor (Cri) are connected in series; conversion circuits (Q1, Q2) for converting a DC voltage of a DC power supply (Vin) into a rectangular-wave voltage, so as to output the rectangular-wave voltage to the series resonant circuit; and a rectifier smoothing circuit (D3, D4, Co) for rectifying and smoothing a voltage generated at the secondary winding (S1) of the transformer, so as to output a DC output voltage to a load, wherein a capacitive element (Cr) including a capacitive component corresponding to a floating capacitance (Cp) equivalently present between the primary winding of the transformer was connected to the current resonant reactor (Lr) in parallel.

Abstract: The present invention includes: a power supply unit 10 outputting an alternating current; and multiple series circuits each of which is connected to an output of the power supply unit 10 and includes at least one winding N1, S1, at least one rectifying element D1, D2, and at least one load LED1a, 2a, which are connected in series. Currents flowing through the multiple series circuits are balanced based on an electromagnetic force generated at the at least one winding N1, S1.

Abstract: Provided is a fuel cell system which can perform sufficient scavenging during a current system operation even if required sufficient scavenging during the previous system stop is not performed. When a control device detects that a system start command is input and a low temperature mode flag is turned “ON”, the control device compares a measured impedance during the previous system stop stored in a measured impedance memory to a low temperature start target impedance It stored in a reference impedance memory, to judge whether or not a scavenging process performed during the previous system stop has been insufficient. When the control device judges that the scavenging process is insufficient, an immediate warm-up operation is executed during the current system operation to immediately raise the temperature.

Abstract: A current balancing apparatus includes a first transformer having a first primary winding and a first secondary winding electromagnetically coupled with the first primary winding, the first primary winding having a first end connected to a first load that passes a first current; a second transformer having a second primary winding and a second secondary winding electromagnetically coupled with the second primary winding, the second primary winding having a first end connected to a second load that passes a second current having an AC component substantially having a 180-degree phase difference with respect to the first current; and a series circuit including the first secondary winding, the second secondary winding, and a current smoother, to balance the first current and second current with each other.

Abstract: A power supply system is provided with a plurality of driving motors, a power converter, and a plurality of power supplies which supply the driving motors with power and have different output voltages. Each power supply is connected with at least one driving motor through the power converter and with at least one driving motor through a path which does not include the power converter.

Abstract: The present invention seeks, when a temporary abnormality occurs in a voltage converter, a recovery of the voltage converter, and minimizes the inadequacy of the drive power. In a fuel cell system comprising an electric storage device disposed with a voltage converter, in the case where an abnormality occurs in the voltage converter, the voltage converter is stopped once, an attempt is made to recover the voltage converter to a normal state after the voltage converter is stopped, and drive power is generated in at least a fuel cell until the voltage converter recovers to the normal state. It is preferred that an upper limit of the power which can be generated when the voltage converter recovers to the normal state be set to a value lower than an upper limit of power obtained prior to the occurrence of the abnormality. Further, it is preferred that the limit be canceled step by step when recovering the voltage converter to a normal state.

Abstract: In a DC-DC converter of the present invention, a converting circuit converts a DC-DC voltage outputted from a DC power supply into an AC voltage, and to output to a series circuit in which a primary winding of a first transformer, a first reactor, and a current resonance capacitor are connected to one another in series. A primary winding of a second transformer, a primary winding of a third transformer, and a second reactor constitute a closed loop. A secondary winding of the second transformer and a secondary winding of the third transformer are connected in series to both ends of a secondary winding of the first transformer. A first rectifying/smoothing circuit rectifies and smoothes a voltage of the secondary winding of the second transformer. A second rectifying/smoothing circuit rectifies and smoothes a voltage of the secondary winding of the third transformer.

Abstract: A direct-current converter includes a high-frequency converting circuit converting voltage of a direct-current power source to alternating-current voltage, a transformer having primary and secondary windings P, S and a rectification smoothing circuit rectifying and smoothing voltage induced in the secondary winding. This converting circuit includes other transformer having first and second windings n1, n2, switching element Q1 having a source connected to a negative pole of the power source and a drain connected to a positive pole thereof through winding n1, and switching element Q2 having a source connected to the negative pole of the power source and a drain connected to the positive pole thereof through winding n2, element Q2 being turned on/off alternately to element Q1 being turned on/off. Winding P is connected to a point between winding n1 and the drain of element Q1 and another point between winding n2 and the drain of element Q2.

Abstract: A DC conversion apparatus comprises a first transformer, a second transformer, a parallel circuit having series circuits connected in parallel, one of the series circuits including a reactor and a primary winding of the first transformer, the other series circuit including a reactor and a primary winding of the second transformer, a conversion circuit converting a DC voltage of a DC power source into an AC voltage and outputting it to the parallel circuit, a first rectifying-smoothing circuit rectifying and smoothing a first voltage generated by a first secondary windings of the first transformer into a first DC output, and a second rectifying-smoothing circuit rectifying and smoothing a second voltage generated by a first secondary windings of the second transformer into a second DC output that is different from the first voltage. The second secondary windings of the first transformer are connected in parallel with the first secondary windings of the second transformer.

Abstract: A DC converter has a transformer with loosely coupled primary and secondary windings, a main switch connected in series with the primary winding of the transformer, and a series circuit connected to ends of one of the primary winding and main switch. The series circuit includes a clamp capacitor and an auxiliary switch. The main and auxiliary switches are alternately turned on/off so that a voltage of the secondary winding of the transformer is synchronously rectified with synchronous rectifiers and is smoothed with smoothing elements, to provide a DC output. The DC converter also includes a tertiary winding provided for the transformer, tightly coupled with the primary winding, and configured to generate a voltage that drives the synchronous rectifiers.

Abstract: A fuel cell system that can continue a stable operation of a fuel cell and perform uninterrupted operation of the system even upon the occurrence of an abnormality in a voltage converter, and a mobile body. A fuel cell system where an accumulator device is connected to a load via a voltage converter in parallel with a fuel cell includes an auxiliary equipment connected nearer the fuel cell than the voltage converter, and a control device for controlling the voltage converter and the auxiliary equipment. The control device changes the operational point of the auxiliary equipment when an abnormality has occurred in the voltage converter.

Abstract: In a DC-DC converter of the present invention, a converting circuit converts a DC-DC voltage outputted from a DC power supply into an AC voltage, and to output to a series circuit in which a primary winding of a first transformer, a first reactor, and a current resonance capacitor are connected to one another in series. A primary winding of a second transformer, a primary winding of a third transformer, and a second reactor constitute a closed loop. A secondary winding of the second transformer and a secondary winding of the third transformer are connected in series to both ends of a secondary winding of the first transformer. A first rectifying/smoothing circuit rectifies and smoothes a voltage of the secondary winding of the second transformer. A second rectifying/smoothing circuit rectifies and smoothes a voltage of the secondary winding of the third transformer.

Abstract: A direct-current converter includes a high-frequency converting circuit converting voltage of a direct-current power source to alternating-current voltage, a transformer having primary and secondary windings P, S and a rectification smoothing circuit rectifying and smoothing voltage induced in the secondary winding. This converting circuit includes other transformer having first and second windings n1, n2, switching element Q1 having a source connected to a negative pole of the power source and a drain connected to a positive pole thereof through winding n1, and switching element Q2 having a source connected to the negative pole of the power source and a drain connected to the positive pole thereof through winding n2, element Q2 being turned on/off alternately to element Q1 being turned on/off. Winding P is connected to a point between winding n1 and the drain of element Q1 and another point between winding n2 and the drain of element Q2.