Abstract: An auxiliary circuit to inject fault current to a grid is provided. The circuit includes a pair of transformers including a first transformer and a second transformer, and a pair of SCRs including a first SCR and a second SCR. Each SCR remains in an OFF state and an ON state when AC voltage of the grid is in normal range and fault range, respectively. The circuit includes a capacitor electrically connected between the first transformer, the second transformer, and the first SCR. The circuit includes a diode biased by the second transformer and the capacitor to enable charging of the capacitor to a peak of AC voltage during one polarity of AC voltage when the AC voltage is in normal range. The capacitor discharges via the first SCR and the first transformer by injecting the fault current into the grid when the AC voltage is in the fault range.

Abstract: A microgrid power system includes a power module configured to generate direct current (DC) power, an inverter module having a DC side and an AC side, and configured to invert DC power received from the power module on the DC side and output alternating current (AC) power on the AC side, a DC bus electrically connecting an output of the power module to an input on the DC side of the inverter module, an AC load bus configured to electrically connect an output on the AC of the inverter module to an AC load, an energy storage device electrically connected to the DC bus, and a kinetic storage device (KSD) device electrically connected to the AC load bus on the AC side of the inverter module.

Abstract: A power generation system includes a power source that is configured to communicate with at least one of a downstream load or a downstream device by changing a voltage on a power bus between the power source and the at least one of the downstream load or the downstream device, while power source provides power on the power bus to the at least one of the downstream load or the downstream device.

Abstract: A system for fuel cell based microgrid is provided. The system includes a plurality of fuel cell modules to generate DC power. The system includes a plurality of dual-mode inverters (DMIs) to convert the DC power into AC power. The system includes a plurality of DC switches to electrically connect or disconnect a fuel cell module from a DC bus. The DC bus is electrically coupled to the plurality of the DC switches. The plurality of DMIs includes a first set of DMIs, second set of DMIs, and a third set of DMIs. The first set is configured to electrically connect a first set of fuel cell modules with a grid. The second set of DMIs is configured to electrically connect a second set of fuel cell modules with a first load. The third set of DMIs is configured to electrically connect the DC bus with the first load.

Abstract: Excess DC current generated by a fuel cell stack may be provided to a current source inverter, and an AC current may be output by the current source inverter to a grid side bus. The AC current on the grid side bus may be used to support a load demand on a microgrid side bus or provided to a power grid. Various transmission buses and electric conditioning and control devices, such as rectifiers, current source inverters, motors, generators, electric contactors, relays, and/or transfer switches may be configured to use the AC current on the grid side bus to provide an AC current to the microgrid side bus to support the load demand on a microgrid side bus.

Abstract: A power control device for an electrolyzer that is configured to encode power curtailment information as a DC bus voltage level using a DC droop characteristic in first stage and decode the DC bus voltage to power information in a second stage.

Abstract: A power control device for an electrolyzer that is configured to receive electrical current from a plurality of electrical power sources, rectify alternating current from a first subset of the plurality of electrical power sources, convert direct current from a second subset of the plurality of electrical power sources, provide power from the first subset and the second subset of electrical power sources to an energy bus, and receive, at the electrolyzer, power from the energy bus.

Abstract: A power generation system includes a power source that is configured to communicate with at least one of a downstream load or a downstream device by changing a voltage on a power bus between the power source and the at least one of the downstream load or the downstream device, while power source provides power on the power bus to the at least one of the downstream load or the downstream device.

Abstract: Systems, devices, methods, and instructions for operating an electrolyzer, including setting a nominal frequency or a nominal voltage of a connected electrical power system, the electrolyzer being configured to deliver a rated production level at the nominal frequency or the nominal voltage, setting an adjustable dead band at or near the nominal frequency or the nominal voltage, and reducing hydrogen generation and reducing power consumption if the frequency drops below the nominal frequency or if the voltage drops below the nominal voltage.

Abstract: A power generation method includes providing power from a first DC power source to a load, while a second DC power source is electrically disconnected from the load, electrically connecting the second DC power source to the load and providing power from the second DC power source to the load if an output voltage from the first DC power source drops below a threshold voltage and an output voltage from the second DC power source is not below the threshold voltage, and electrically disconnecting the first DC power source from the load if an output current of the first DC power source is below a threshold current.

Abstract: A fuel cell system column includes a first terminal plate connected to a first electrical output of the column, a second terminal plate connected to a second electrical output of the column, at least one first fuel cell stack located in a middle portion of the column between the first terminal plate and the second terminal plate, and at least one electrical connection which is electrically connected to the middle portion of the column and which is configured to provide a more uniform fuel utilization across the first column.

Abstract: Excess DC current generated by a fuel cell stack may be provided to a current source inverter, and an AC current may be output by the current source inverter to a grid side bus. The AC current on the grid side bus may be used to support a load demand on a microgrid side bus or provided to a power grid. Various transmission buses and electric conditioning and control devices, such as rectifiers, current source inverters, motors, generators, electric contactors, relays, and/or transfer switches may be configured to use the AC current on the grid side bus to provide an AC current to the microgrid side bus to support the load demand on a microgrid side bus.

Abstract: A method for operating a fuel cell system includes drawing a base level DC electric energy from a first fuel cell of a first type to a combined DC bus, measuring a DC voltage at the combined DC bus, determining whether the DC voltage at the combined DC bus falls short of a DC voltage threshold, and drawing a variable DC electric energy from a second fuel cell of a second type different from the first type in response to determining that the DC voltage at the combined DC bus falls short of the DC voltage threshold.

Abstract: A microgrid system includes first and second DC power sources electrically connected to respective first and second DC electrical power busses, a first uninterruptable power module electrically connected to the first DC electrical power bus and configured to be connected to an alternating current (AC) load, a second uninterruptable power module electrically connected to the second DC electrical power bus and configured to be connected to the AC load, a first bi-directional AC/DC inverter having a DC end and an AC end, where the first DC electrical power bus is connected to the DC end of the first bi-directional AC/DC inverter, a second bi-directional AC/DC inverter having DC and AC ends, where the second DC electrical power bus is connected to the DC end of the second bi-directional AC/DC inverter, and an AC electrical power bus electrically connected to the first and second bi-directional AC/DC inverters at their AC ends.

Abstract: Various embodiments include methods and systems for managing electric power demand distribution across electric power generators in a microgrid. The system may include electric power generator clusters each having electric power generators, electric power output units each electrically connected to at least one of the electric power generator clusters, an energy storage unit electrically connected to an electric power output unit, and a control device. The control device may be configured to determine whether an energy availability of the energy storage unit is less than an energy availability threshold, calculate a sharing multiplication factor for an electric power generator cluster in response to determining that the energy availability of the energy storage unit is less than an energy availability threshold, and calculate a sharing electric power demand for the electric power generator cluster using the sharing multiplication factor.

Abstract: A microgrid includes a power system configured to output system power and an automatic transfer switch (ATS). The ATS includes a normal terminal that is electrically connected to a grid power line configured to receive grid power from a power utility, an emergency terminal that is electrically connected to a system power line configured to receive system power from the power system, and a load terminal that is electrically connected to a critical load line configured to provide power to a critical load. The microgrid also includes a bypass line electrically connected to the system power line and the critical load line, so as to bypass the ATS, and a circuit breaker configured to control power flow through the bypass line.

Abstract: During a steady-state mode of operating a fuel cell system, a system power is generated by fuel cells and is provided via a steady-state bus to a first BOP load, to a second BOP load, and to a power grid via a transformer and via at least one of a bi-directional first inverter or a bi-directional second inverter. During startup mode operation of the fuel cell system, external power from the power grid is provided via the transformer, via one of the first or second inverters and via a startup bus to the first BOP load and the second BOP load.

Abstract: A method of transporting a battery module includes transporting the battery module containing at least one battery and a backplane disposed in a cabinet to an operating site such that the at least one battery is electrically isolated from the backplane during the transporting, installing the battery module at the operating site, and electrically connecting the at least one battery to the backplane after the transporting.

Abstract: A method of operating a power generator having a first electrical output electrically connected to a utility grid and a second electrical output electrically connected to a load includes detecting if the first electrical output of the power generator is electrically disconnected from the utility grid, and electrically connecting at least a neutral line of the first electrical output to ground in response to detecting that the first output is electrically disconnected from the utility grid.

Abstract: A method of operating a power generator having a first electrical output electrically connected to a utility grid and a second electrical output electrically connected to a load includes detecting if the first electrical output of the power generator is electrically disconnected from the utility grid, and electrically connecting at least a neutral line of the first electrical output to ground in response to detecting that the first output is electrically disconnected from the utility grid.