A drive circuit comprising a DC bus configured to supply power to a load, a first fuel cell coupled to the DC bus and configured to provide a first power output to the DC bus, and a second fuel cell coupled to the DC bus and configured to provide a second power output to the DC bus supplemental to the first fuel cell. The drive circuit further includes an energy storage device coupled to the DC bus and configured to receive energy from the DC bus when a combined output of the first and second fuel cells is greater than a power demand from a load, and provide energy to the DC bus when the combined output of the first and second fuel cells is less than the power demand from the load.

An electrical power generating system for providing auxiliary or backup power to a load bus. The system may be used indoors, and generally includes a fuel cell unit comprising a first DC output, an electrical storage unit comprising a DC input coupled to the first DC output of the fuel cell, the electrical storage unit further comprising a second DC output. An inverter coupled to the second DC output receives power, the inverter comprising a first AC output. The system includes a contactor connected between the first AC output and an AC load bus. The AC load bus comprises an AC voltage, and a controller comprising inputs is adapted to sense a phase, a frequency, and a magnitude of the first AC output and the AC voltage and close the contactor when they substantially match.

Disclosed are a grid-connected power conversion system and a control method thereof. The grid-connected power conversion system includes a fuel cell stack generating a DC voltage, a power conversion system (PCS) converting the DC voltage supplied from the stack into an AC voltage, a multi-input transformer including a primary coil having a plurality of voltage input terminals and a secondary coil transforming a magnitude of the voltage applied to the primary coil and outputting the transformed voltage, the plurality of voltage input terminals determining the number of turns of the primary coil differently from each other, one of the plurality of voltage input terminals receiving the AC voltage converted in the PCS, and a controller selecting the one of the plurality of voltage input terminals of the multi-input transformer based on the magnitude of the DC voltage generated from the stack and determining whether to replace the stack.

An electrical power generating system for providing auxiliary or backup power to a load bus. The system may be used indoors, and generally includes a fuel cell unit comprising a first DC output, an electrical storage unit comprising a DC input coupled to the first DC output of the fuel cell, the electrical storage unit further comprising a second DC output. An inverter coupled to the second DC output receives power, the inverter comprising a first AC output. The system includes a contactor connected between the first AC output and an AC load bus. The AC load bus comprises an AC voltage, and a controller comprising inputs is adapted to sense a phase, a frequency, and a magnitude of the first AC output and the AC voltage and close the contactor when they substantially match.

A metal plate is formed by stacking a plurality of thin metal plates. The thin metal plates are respectively provided with a plurality of through holes passing therethrough in the thickness direction. The metal plate is provided with penetration spaces 1c formed by the through holes of the plurality of thin metal plates that are in communication with each other in a state in which thin metal plates are stacked. A metal plate aspect ratio that is a value obtained by dividing the thickness of each of the thin metal plates by the inner diameter of the through holes is 2 or less. A metal support aspect ratio that is a value obtained by dividing the overall thickness of the metal plate by the minimum inner diameter of the penetration spaces is 3 or more.

An apparatus (10) configured to determine reactant purity comprising: a first fuel cell (11) configured to generate electrical current from the electrochemical reaction between two reactants, having a first reactant inlet (13) configured to receive a test reactant comprising one of the two reactants from a first reactant source (7, 5, 16); a second fuel cell (12) configured to generate electrical current from the electrochemical reaction between the two reactants, having a second reactant inlet (14) configured to receive the test reactant from a second reactant source (5); a controller (20) configured to apply an electrical load to each fuel cell and determine an electrical output difference, OD.sub.t, between an electrical output of the first fuel cell (11) and an electrical output of the second fuel cell (12), and determine a difference between a predicted output difference and the determined electrical output difference, OD.sub.t, the predicted output difference determined based on a historical output of difference and a historical rate of change in said output difference determined at an earlier time, said controller (20) configured to provide a purity output indicative of the test reactant purity at least based on the difference between the predicted and determined output difference.

In a power generation system, exhausted fuel gas exhausted from a solid oxide fuel cell (SOFC) is used as a fuel of a first combustor or a second combustor of a gas turbine, and at the same time, a part of compressed air compressed by a compressor of the gas turbine is used to drive the SOFC. The gas turbine includes the first combustor for burning fuel gas which is different from the exhausted fuel gas, a first turbine configured to be driven by combustion gas supplied from the first combustor, the second combustor for burning at least a part of the exhausted fuel gas, and a second turbine coupled with the first turbine and configured to be driven by combustion gas supplied from the second combustor.

Devices which internally control and regulate voltage of a super-capacitor cell or stack thereof during charge-discharge cycles, methods for controlling and regulating voltage of a super-capacitor cell or stack thereof with these devices and methods for production of the devices are provided.

An EMS (200) receives at least one of a message indicating a rated output of the storage battery (141) and a message indicating number of charged and discharged times of the storage battery (141), from the power storage apparatus (140).

An apparatus (10) configured to determine reactant purity comprising: a first fuel cell (11) configured to generate electrical current from the electrochemical reaction between two reactants, having a first reactant inlet (13) configured to receive a test reactant comprising one of the two reactants from a first reactant source (7, 5, 16); a second fuel cell (12) configured to generate electrical current from the electrochemical reaction between the two reactants, having a second reactant inlet (14) configured to receive the test reactant from a second reactant source (5); a controller (20) configured to apply an electrical load to each fuel cell and determine an electrical output difference, OD.sub.t, between an electrical output of the first fuel cell (11) and an electrical output of the second fuel cell (12), and determine a difference between a predicted output difference and the determined electrical output difference, OD.sub.t, the predicted output difference determined based on a historical output of difference and a historical rate of change in said output difference determined at an earlier time, said controller (20) configured to provide a purity output indicative of the test reactant purity at least based on the difference between the predicted and determined output difference.