A method for controlling an output of a fuel cell stack is provided. The method includes calculating a total requirement current value to be output from a plurality of fuel cell stacks in a fuel cell electric vehicle (FCEV) including the plurality of fuel cell stacks. The calculated total requirement current value is then allocated to each fuel cell stack based on a voltage of the fuel cell stack.

A power generation control system includes a plurality of fuel cell systems mounted in an electric device that operates using electric power, a battery mounted in the electric device, and a control device configured to control each of the plurality of fuel cell systems on the basis of states of the plurality of fuel cell systems, a state of the battery, and required power of the plurality of fuel cell systems.

An apparatus of solid oxide fuel cells (SOFC) is provided. The SOFCs generate power and are grid-tied. The apparatus comprises a power-generating side; and a grid-connecting side using an elementary household power management. The apparatus solves problems like low voltage, high current, voltage oscillation, voltage dips, long generator-starting time, etc. The apparatus is not only used as a stable power supply (base load), but also helps adjust the regional peak electricity demands. The features include the following: 1. A grid is tied, where output power does not pass through a direct-current boost converter and, thus, has no loss from it. 2. Injures, including voltage oscillation and sudden unloading after dumping, are reduced for avoiding further damages to cell sheets. 3. With the coordination of elementary power management and the integration of grid, the limitation of long-awaiting generator-starting time is crossed out and convenience of immediate power use is achieved.

A fuel cell system includes: a fuel cell unit; first and second supply systems; a switching device; a switching control unit, when required power of the fuel cell unit is equal to or smaller than a threshold; an open circuit voltage obtaining unit; and a supply system control unit.

To provide a fuel cell system configured to reduce the drying of the inside of the fuel cell stack and increase the power generation performance of the fuel cell stack by reducing a circulation gas flow rate during high temperature operation. Disclosed is a fuel cell system comprising: a fuel cell stack, an ejector, a first injector which supplies fuel gas to the ejector, a second injector which has a smaller fuel gas injection amount than the first injector and which supplies the fuel gas to the ejector, a third injector which supplies the fuel gas to fuel electrodes of the fuel cell stack, a fuel gas supplier, a first supply flow path, a second supply flow path which enables the supply of the fuel gas from the third injector to the fuel electrodes of the fuel cell stack, a circulation flow path, a temperature detector, and a controller.

A control device for a fuel cell system comprises a hydrogen deficiency judging part configured to judge if a hydrogen deficiency which is a state in which an amount of hydrogen supplied to the fuel cell is insufficient compared with an amount of hydrogen required for power generation has occurred, a hydrogen deficiency elimination judging part configured to judge if the hydrogen deficiency has been eliminated after the hydrogen deficiency judging part judges that the hydrogen deficiency has occurred and a breakage control part configured to make the circuit breaker temporarily break an electrical connection of the fuel cell and the electrical load part when the hydrogen deficiency elimination judging part judges that the hydrogen deficiency has been eliminated.

An energy regulation method for a fuel cell energy supply system including a plurality of fuel cell power generation modules, a plurality of power conversion modules, and a communication control module connected to the plurality of power conversion modules includes: calculating a parameter average value based on an energy state parameter of the fuel cell power generation module; calculating a compensation factor depending on the energy state parameter and the parameter average value; calculating a control parameter reference value of each of the power conversion modules based on a droop algorithm, and multiplying the control parameter reference value by the corresponding compensation factor to obtain a control parameter set value of the power conversion module; and regulating the corresponding fuel cell power generation modules depending on the control parameter set value.

A fuel cell system includes: a first fuel cell; a second fuel cell having a greater maximum power output than the first fuel cell; and a controller configured to cause the first fuel cell to generate greater electric power greater than the second fuel cell when the requested power is smaller than a first threshold, cause the second fuel cell to generate greater electric power than the first fuel cell when the requested power is a second threshold, which is the first threshold or greater and smaller than a third threshold that is greater than the second threshold, is 70% of the maximum power output of the second fuel cell or grater, and is 100% of the maximum power output of the second fuel cell or smaller, and cause both the first and second fuel cells to generate electric power when the requested power is the third threshold or greater.

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.

A preservation system comprises: a fuel cell; and an oxidant agent supply passage, positioned inside the power supply device, for supplying the oxidant agent to the fuel cell, and (i) a piping positioned outside the power supply device, and (ii) a connecting portion for oxidant agent for connecting the oxidant agent supply passage, to preserve the power supply device configured to be detachable to a work machine. The preservation system comprises: a preservation section for preserving the power supply device detached from the work machine; a purge gas conserving section for conserving a purge gas in order for purging the fuel cell and the oxidant agent supply passage; a purge gas piping, being a piping positioned outside the power supply device; and a purge gas flow rate regulation section for regulating flow rate of the purge gas supplied to the power supply device.