Abstract: Methods are disclosed for starting up a fuel cell system from starting temperatures below 0° C. The methods apply to systems comprising a solid polymer electrolyte fuel cell stack whose cathodes comprise an oxygen reduction reaction (ORR) catalyst and whose anodes comprise both a hydrogen oxidation reaction (HOR) catalyst and an oxidation evolution reaction (OER) catalyst. In the methods, from the beginning of starting up until the fuel cell temperature reaches 0° C., the fuel cell stack current is kept sufficiently low such that the current density drawn does not exceed the stack's capability for the oxidation evolution and the oxygen reduction reactions to occur at the anode and cathode respectively (i.e. current density drawn is less than the stack's maximum OER/ORR current density).

Abstract: In a half-bridge circuit, when a transistor element is turned ON, a primary winding current flows from a power supply to a first primary winding. Then, when the transistor element is turned OFF, (i) a first rectifying element current flows from the secondary winding to the first rectifying element, and a first reverse voltage for a first switching element is applied to the first switching element, or (ii) a second rectifying element current flows from the tertiary winding to the second rectifying element, and a first reverse voltage for a second switching element is applied to the second switching element.

Abstract: In a half-bridge circuit, in a case that a first transistor element is turned ON, a primary winding current flows from a power supply to a primary winding. Then, in a case that the first transistor element is turned OFF, (i) a first rectifying element current flows from a secondary winding to a first rectifying element, or (ii) a second rectifying element current flows from a tertiary winding to a second rectifying element.

Abstract: In a rectifying circuit including a HEMT and a diode connected antiparallel to the HEMT, a forward voltage drop when the diode starts to be conductive is made smaller than a voltage drop when the HEMT is reverse-conductive in an OFF state corresponding to an amount of rectified current when the HEMT is reverse-conductive in an ON state, inductance of a pathway extending through the diode is made larger than inductance of a pathway extending through the HEMT among the pathways connecting a source terminal and a drain terminal of the HEMT, and an amount of charge accumulated in a parasitic capacitance of the diode is made smaller than an amount of charge accumulated in an output capacitance of the HEMT. With this, there is provided a rectifying circuit in which switching loss due to the charge accumulated in the output capacitance of the HEMT is reduced.

Abstract: A solid oxide fuel cell system includes a solid oxide fuel cell, a combustor disposed in a cathode gas supply line of the fuel cell, a fuel supply unit configured to supply a fuel to the combustor, and a cathode gas supply unit configured to supply a cathode gas to the cathode gas supply line. The system further includes a stop control unit configured to perform a stop control of the fuel cell, which includes a control that sets a cathode gas supply amount from the cathode gas supply unit to a predetermined amount and a control that supplies the fuel from the fuel supply unit in a supply amount corresponding to the cathode gas supply amount.

Abstract: Improved methods are disclosed for shutting down and storing a fuel cell system, particularly for below freezing temperature conditions. The methods comprise stopping power production from the fuel cell stack, monitoring its temperature, and repeatedly performing a predetermined warming operation if the stack temperature falls to a normal threshold temperature. In the improved methods, either an initial threshold temperature and/or an initial warming operation are used that differ from the respective normal threshold temperature and the predetermined warming operation.

Abstract: A power supply includes a transformer including a primary winding and a plurality of secondary windings, a primary circuit connected to the primary winding; and a plurality of secondary circuits connected to the plurality of secondary windings, respectively. The secondary circuit performs a power regeneration operation of transmitting power to the primary circuit or the secondary circuit. The secondary circuit includes MOSFETs configured to rectify the power transmitted from a primary side of the transformer and a capacitor configured to store the power that is rectified and is configured to perform a discharge operation of discharging the capacitor and causing a current to flow into a secondary winding of the plurality of secondary windings of the transformer. Thus, the power supply capable of stably outputting a plurality of voltages and having a high power-conversion efficiency is provided.

Abstract: The present invention concerns a starting burner (100a; 100b) for a fuel cell system (1000a; 1000b), having a catalyst (10) with a catalyst inlet (11) and a catalyst outlet (12), a catalyst area (13) being formed between the catalyst inlet (11) and the catalyst outlet (12), and the catalyst area (13) being surrounded by a catalyst wall (14) in a passage direction (D) from the catalyst inlet (11) to the catalyst outlet (12), and an operating fluid guide section (20) for supplying an operating fluid (F1) to the catalyst inlet (11), wherein the operating fluid guide section (20) is arranged outside the catalyst (10) at least in sections along the catalyst wall (14). The invention also concerns a fuel cell system (1000) with the starting burner (100a; 100b) and a method for heating a service fluid (F1) in the fuel cell system (1000a; 1000b).

Abstract: Methods are disclosed for starting up a fuel cell system from starting temperatures below 0° C. The methods apply to systems comprising a solid polymer electrolyte fuel cell stack whose cathodes comprise an oxygen reduction reaction (ORR) catalyst and whose anodes comprise both a hydrogen oxidation reaction (HOR) catalyst and an oxidation evolution reaction (OER) catalyst. In the methods, from the beginning of starting up until the fuel cell temperature reaches 0° C., the fuel cell stack current is kept sufficiently low such that the current density drawn does not exceed the stack's capability for the oxidation evolution and the oxygen reduction reactions to occur at the anode and cathode respectively (i.e. current density drawn is less than the stack's maximum OER/ORR current density).

Abstract: A deformation absorption member for a fuel-cell-stack disposed between an anode side separator and a cathode side separator. The deformation absorption member includes a thin-board-like base material, and a plurality of raised pieces in which extension portions extended from proximal ends are arranged in a grid pattern. Each raised piece of the plurality of raised pieces is formed in a non-rectangular shape in which the width of the extension portion is shorter than the width of the proximal end, and plurality of raised pieces are configured so that the directions of the extension portions of mutually adjacent raised pieces are alternately arranged, and positions of the proximal ends of the mutually adjacent raised pieces are arranged in at least overlapping positions.

Abstract: A fuel cell system has an oxidant supplying device configured to supply oxidant gas to a fuel cell, a fuel supplying device configured to supply fuel gas to the fuel cell and a combustor configured to burn fuel off-gas and oxidant off-gas discharged from the fuel cell and discharge thereof. The a control method for the fuel cell system includes a power generation control step of supplying the fuel gas and the oxidant gas to the fuel cell and causing the fuel cell to generate power. The a control method further includes a stop control step of stopping the supply of the fuel gas to the fuel cell and supplying the oxidant gas to the combustor on the basis of an amount of unburned fuel gas of the fuel cell system in the case of stopping the fuel cell system.

Abstract: Improved methods are disclosed for shutting down and storing a fuel cell system, particularly for below freezing temperature conditions. The methods comprise stopping power production from the fuel cell stack, monitoring its temperature, and repeatedly performing a predetermined warming operation if the stack temperature falls to a normal threshold temperature. In the improved methods, either an initial threshold temperature and/or an initial warming operation are used that differ from the respective normal threshold temperature and the predetermined warming operation.

Abstract: A control method for a fuel cell system with a gas supplying device configured to supply fuel gas and oxidant gas to a fuel cell, includes a power generating operation step of performing a power generating operation for causing the fuel cell to generate power by controlling the fuel gas and the oxidant gas to be supplied to the fuel cell on the basis of a load required of the fuel cell. Further, the control method includes an autonomous operation step of performing an autonomous operation of the fuel cell when the load drops to or below a predetermined value. In the autonomous operation, power supply from the fuel cell system to the load is stopped and the fuel gas is passed to an anode of the fuel cell.

Abstract: Improved methods are disclosed for shutting down and storing a fuel cell system, particularly for below freezing temperature conditions. The methods comprise stopping power production from the fuel cell stack, monitoring the amount of energy remaining in an energy supply, monitoring the stack temperature, and repeatedly performing a predetermined warming operation if the stack temperature falls to a normal threshold temperature and if the amount of energy remaining exceeds a certain minimum amount. In the improved methods, when the amount of remaining energy is less than or equal to the minimum amount, a final warming operation is performed that differs from the predetermined warming operation.

Abstract: A control method for a fuel cell system including a solid oxide fuel cell, an anode gas and a cathode gas being supplied to the fuel cell, the fuel cell performing electric generation corresponding to a load, the fuel cell system controlling gas supply to the fuel cell and the electric generation. The control method including: an electric generating operation step of controlling flow rates of the anode gas and the cathode gas that flow into the fuel cell depending on a magnitude of the load; and a self-sustained operation step of causing the fuel cell to perform self-sustained operation when the load is equal to or less than a predetermined value. The self-sustained operation step includes a gas supply step of supplying the anode gas with a predetermined flow rate and the cathode gas with a predetermined flow rate to the fuel cell.

Abstract: A solid oxide fuel cell system includes a solid oxide fuel cell, a combustor disposed in a cathode gas supply line of the fuel cell, a fuel supply unit configured to supply a fuel to the combustor, and a cathode gas supply unit configured to supply a cathode gas to the cathode gas supply line. The system further includes a stop control unit configured to perform a stop control of the fuel cell, which includes a control that sets a cathode gas supply amount from the cathode gas supply unit to a predetermined amount and a control that supplies the fuel from the fuel supply unit in a supply amount corresponding to the cathode gas supply amount.

Abstract: A fuel cell system has an oxidant supplying device configured to supply oxidant gas to a fuel cell, a fuel supplying device configured to supply fuel gas to the fuel cell and a combustor configured to burn fuel off-gas and oxidant off-gas discharged from the fuel cell and discharge thereof. The a control method for the fuel cell system includes a power generation control step of supplying the fuel gas and the oxidant gas to the fuel cell and causing the fuel cell to generate power.

Abstract: A DC-DC converter includes a transformer, a switching circuit provided on the primary side of the transformer, and a rectifier circuit provided on the secondary side of the transformer. The rectifier circuit includes a first rectifier part that is serially connected body of a first transistor and a second transistor having a first electrode connected to a second electrode of the first transistor. The first and second transistors each include a parasitic diode connected forward between the second and first electrode, and the withstanding voltage between the first and second electrodes of the first transistor is higher than the withstanding voltage between the first and second electrodes of the second transistor.

Abstract: A fuel-cell-stack manufacturing method, includes arranging an extension portion extended from a proximal end of a raised piece on one surface of a base material disposed so as to abut at least one of a cathode side separator and the anode side separator, and setting an interval between the anode side separator and the cathode side separator along a lamination direction so that deformation of the raised piece exceeds an elastic deformation region and enters a plastic deformation region, and is also in a region in which the proximal end moved due to the deformation does not come in contact with the cathode side separator or the anode side separator.

Abstract: A high-withstand-voltage normally-on transistor and a low-withstand-voltage normally-off transistor are connected in series, and diodes are provided in reverse parallel to the transistor. A gate terminal of the transistor is connected to a source terminal of the transistor, and a gate driving circuit that outputs a control signal to a gate terminal of the transistor is provided. Forward voltage of the diode is made lower than forward voltage of the diode, and an inductance component of a path connecting nodes via the diode is made greater than an inductance component of a path connecting the nodes via the diode. Accordingly, a switching circuit which includes transistors connected in series and in which transient current at a time of turning off is reduced is provided.