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: Systems and methods for microgrid-power distribution management when distributed energy resources transition between operating modes. The system includes a fuel cell system that generates DC power and a multi-mode inverter system that operates in one of the operating modes based on an availability status of grid, a site controller that receives electrical signal(s) facilitates the multi-mode inverter system to transition between the operating modes, generates a control signal based at least on an load operating input and transitioning of the multi-mode inverter system, a DC braking module that turns ON in response to receipt of the control signal, dissipates excess energy from the DC bus when the DC voltage value is greater than a threshold voltage value and energy storage module that turns ON in response to receipt of the control signal, supplies power to the DC bus, when the DC voltage value is less than the load operating input.

Abstract: A method of electrolyzer system load configuration includes determining that at least one sensor of multiple heater power supplies is functional, determining whether multiple heater power supplies are connected in parallel, testing a connection between the plural heater power supplies and one or more heaters, and transmitting an electrolyzer system load configuration to one or more electrolyzer module controllers.

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 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 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 fuel cell system includes a power module housing including a hotbox cabinet and an auxiliary cabinet, a hotbox disposed in the hotbox cabinet and including a stack of fuel cells, electronic components disposed in the auxiliary cabinet, a system blower configured to provide air into the power module housing, a hotbox air inlet conduit fluidly connecting the system blower to the hotbox, a heat exchanger configured to preheat air in the hotbox air inlet conduit by extracting heat from cathode exhaust output from the hotbox, and a cathode exhaust outlet conduit fluidly connecting a cathode exhaust outlet of the hotbox to the heat exchanger.

Abstract: A method includes outputting an alternating current (AC) waveform from an inverter module to a plurality of loads, outputting a fault waveform from the inverter module to a first load of the plurality of loads in response to a fault condition associated with the first load, and outputting the AC waveform from the inverter module to at least some of the plurality of loads if the fault condition is cleared before a recovery period expires or disconnecting the inverter module from the plurality of loads if the fault condition is not cleared before the recovery period expires.

Abstract: Systems and methods for facilitating a medium voltage microgrid operation to manage critical loads are disclosed. The system includes at least two fuel cell systems that operate in one of at least two operating modes including a grid-forming mode and a grid-following mode, based on an operation of at least two utility feeders of a grid. The system includes a controller that receives values corresponding to electrical parameter(s) from at least two utility circuit breakers and a load circuit breaker, detects availability status of the utility circuit breakers to supply power to corresponding at least two portions of the critical load, and a connection status of the load circuit breaker, based on the values, and facilitates the at least two fuel cell systems to operate in one of the at least two operating modes. Further, the system is scalable, redundant, and reliable, and reliability and redundancy are customizable.

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 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: Systems and methods for determining a site control architecture for controlling inverter(s) in a microgrid-based site are disclosed. The system includes a site controller, stamp controller(s), and inverter controller(s) communicatively coupled with each other. The site controller receives site operating input(s) associated with a microgrid-based site, determines a site control architecture for implementation on the microgrid-based site to stabilize an operation of the microgrid-based site, receives values corresponding to electrical parameter(s) associated with electrical point(s) in the microgrid-based site, transmits a control message to each of the stamp controller(s) and the inverter controller(s), and facilitates each of the stamp controller(s) and the inverter controller(s) to operate in one of at least two control modes for implementing the determined site control architecture, in response to the control message.

Abstract: Systems and methods for facilitating a medium voltage microgrid operation to manage critical loads are disclosed. The system includes at least two fuel cell systems that operate in one of at least two operating modes including a grid-forming mode and a grid-following mode, based on an operation of at least two utility feeders of a grid. The system includes a controller that receives values corresponding to electrical parameter(s) from at least two utility circuit breakers and a load circuit breaker, detects availability status of the utility circuit breakers to supply power to corresponding at least two portions of the critical load, and a connection status of the load circuit breaker, based on the values, and facilitates the at least two fuel cell systems to operate in one of the at least two operating modes. Further, the system is scalable, redundant, and reliable, and reliability and redundancy are customizable.

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: A method includes outputting an alternating current (AC) waveform from an inverter module to a plurality of loads, outputting a fault waveform from the inverter module to a first load of the plurality of loads in response to a fault condition associated with the first load, and outputting the AC waveform from the inverter module to at least some of the plurality of loads if the fault condition is cleared before a recovery period expires or disconnecting the inverter module from the plurality of loads if the fault condition is not cleared before the recovery period expires.

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.