Abstract: A multi-port split-phase power system that includes a control panel including a plurality of breakers, a multi-port converter including an AC port coupled to a second breaker, a DC port coupled to a DC energy source device, and galvanically isolated converters coupled to the AC port and DC port, where the AC port includes a first line, a second line, and a neutral and structured to supply, from the AC energy source device during islanded mode, at least one of 240V to the load device via the first line and the second line or 120V to the load device via the first line and the neutral, and an energy management system including a software for controlling the plurality of breakers, the energy management system structured to perform islanding, reconnection to the utility, and interlocking of the plurality of breakers during the islanding.

Abstract: Electrically connecting a first node of a first power grid to a second node of a second power grid includes: determining a phase angle of at least one phase of an AC voltage at the first node in the first power grid; determining a phase angle of at least one phase of an AC voltage at the second node in the second power grid; determining a phase angle metric based on comparing the phase angle of the AC voltage in the first power grid to the phase angle of the AC voltage in the second power grid; comparing the phase angle metric to a phase angle threshold; and if the phase angle metric is equal to or exceeds the phase angle threshold, controlling a dispatchable energy source in the first power grid in a P-Q control mode to adjust the phase angle of at least one phase of the AC voltage at the first node.

Abstract: A multi-port split-phase power system that includes a control panel including a plurality of breakers, a multi-port converter including an AC port coupled to a second breaker, a DC port coupled to a DC energy source device, and galvanically isolated converters coupled to the AC port and DC port, where the AC port includes a first line, a second line, and a neutral and structured to supply, from the AC energy source device during islanded mode, at least one of 240V to the load device via the first line and the second line or 120V to the load device via the first line and the neutral, and an energy management system including a software for controlling the plurality of breakers, the energy management system structured to perform islanding, reconnection to the utility, and interlocking of the plurality of breakers during the islanding.

Abstract: Electrically connecting a first node of a first power grid to a second node of a second power grid includes: determining a phase angle of at least one phase of an AC voltage at the first node in the first power grid; determining a phase angle of at least one phase of an AC voltage at the second node in the second power grid; determining a phase angle metric based on comparing the phase angle of the AC voltage in the first power grid to the phase angle of the AC voltage in the second power grid; comparing the phase angle metric to a phase angle threshold; and if the phase angle metric is equal to or exceeds the phase angle threshold, controlling a dispatchable energy source in the first power grid in a P-Q control mode to adjust the phase angle of at least one phase of the AC voltage at the first node.

Abstract: Power is provided from a power source and a status of the power source is signaled by controlling a waveform of an AC voltage generated from the power source. The status may include, for example, a capacity of the power source. In some embodiments, a frequency of the AC voltage may be controlled to signal the status. The power source may include, for example, an uninterruptible power supply (UPS), and signaling a status of the power source may include controlling an inverter of the UPS to signal the status. Related systems are also described.

Abstract: Power is provided from a power source and a status of the power source is signaled by controlling a waveform of an AC voltage generated from the power source. The status may include, for example, a capacity of the power source. In some embodiments, a frequency of the AC voltage may be controlled to signal the status. The power source may include, for example, an uninterruptible power supply (UPS), and signaling a status of the power source may include controlling an inverter of the UPS to signal the status. Related systems are also described.

Abstract: Power is provided from a power source and a status of the power source is signaled by controlling a waveform of an AC voltage generated from the power source. The status may include, for example, a capacity of the power source. In some embodiments, a frequency of the AC voltage may be controlled to signal the status. The power source may include, for example, an uninterruptible power supply (UPS), and signaling a status of the power source may include controlling an inverter of the UPS to signal the status. Related systems are also described.

Abstract: A system and method for estimating operating characteristics of an induction motor is disclosed. The system includes a motor control device that is electrically connectable between a motor and a power source. The motor control device includes a plurality of switching devices comprising at least one thyristor corresponding to a respective phase of the motor. The motor control device also includes a controller programmed to disconnect the power source from the motor for a predetermined time period following a first plurality of cycles of a mains phase voltage of the power source. The controller is further programmed to measure a back-emf voltage during the predetermined time period, estimate an operating characteristic of the motor from the measured back-emf voltage, and trigger the plurality of switching devices to reconnect the power source to the motor following estimation of the operating characteristic.

Abstract: An energy system includes renewable energy sources each including an inverter. The renewable source inverters are coupled to a distribution line in a manner wherein power combines additively. The system also includes an energy storage source including an energy storage inverter coupled to the distribution line between the point of interconnection and the renewable source inverters. Finally, a control system is structured to: (i) control a voltage at the point of interconnection by controlling a renewable source reactive power output by the renewable source inverters and an energy storage reactive power output by the energy storage inverter, and (ii) provide power ramp rate control for the renewable energy system by controlling at least one of a renewable source real power output by each of the renewable source inverters and a first energy storage real power output by the energy storage inverter.

Abstract: A system for detecting islanding of a microgrid includes a number of power sources to output real power and controlled reactive power injection; a number of controllers each controlling one of the number of power sources; and an output from the microgrid powered by the number of power sources. A number of electrical switching apparatus electrically connect the output from the microgrid to a grid and electrically disconnect the output from the microgrid from the grid. A microgrid controller detects islanding of the microgrid with respect to the grid, and sends a number of commands to a number of the number of controllers in order to control reactive power injection by a number of the number of power sources. A communication channel is between the microgrid controller and the number of controllers. A number of microgrid loads are powered by the output from the microgrid.

Abstract: An area electric power system includes a number of direct current power sources, and a number of inverters operatively associated with the number of direct current power sources. Each of the number of inverters is structured to provide real power and controlled reactive power injection to detect islanding. An output is powered by the number of inverters. A number of electrical switching apparatus are structured to electrically connect the number of inverters to and electrically disconnect the number of inverters from a utility grid. A number of devices are structured to detect islanding with respect to the utility grid responsive to a number of changes of alternating current frequency or voltage of the output.

Abstract: A power conversion system includes a number of photovoltaic arrays, a number of inverters, a transformer, and processor. The processor is structured to control the number of inverters and operate the power conversion system to provide maximum efficiency of power conversion by the number of photovoltaic arrays, the number of inverters and the transformer, and to maximize power output from the number of photovoltaic arrays.

Abstract: A system and method for controlling switching in an AC-AC converter is disclosed. A controller for the AC-AC converter determines a direction of current flow on supply lines that provide AC power to the AC-AC converter and determines a switching pattern for each of a plurality of line-side switches and each of a plurality of floating-neutral side switches in the AC-AC converter based on the determined direction of current flow on each of the supply lines. The controller causes the line-side switches and the floating-neutral side switches to operate in an ON or OFF condition according to the determined switching pattern, such that a controlled current flow is output from the AC-AC converter. The controller also implements a safe-switching routine when transitioning from a first switching pattern to a second switching pattern that prevents a non-zero current from being interrupted during the transitioning between the first and second switching patterns.

Abstract: An integrated circuit includes a hybrid switch having first and second switching devices of different type therein. A control circuit is provided, which is configured to drive the first and second devices with respective first and second control signals having first and second unequal duty cycles, respectively, when the first and second devices are supporting a forward current in a first current range. The control circuit is further configured to drive the first and second devices with respective third and fourth control signals having third and fourth unequal duty cycles, respectively, when the first and second devices are supporting a forward current in a second current range outside the first current range. The first duty cycle may be greater than the second duty cycle and the third duty cycle may be less than the fourth duty cycle.

Abstract: An energy system includes renewable energy sources each including an inverter. The renewable source inverters are coupled to a distribution line in a manner wherein power combines additively. The system also includes an energy storage source including an energy storage inverter coupled to the distribution line between the point of interconnection and the renewable source inverters. Finally, a control system is structured to: (i) control a voltage at the point of interconnection by controlling a renewable source reactive power output by the renewable source inverters and an energy storage reactive power output by the energy storage inverter, and (ii) provide power ramp rate control for the renewable energy system by controlling at least one of a renewable source real power output by each of the renewable source inverters and a first energy storage real power output by the energy storage inverter.

Abstract: An integrated circuit includes a hybrid switch having first and second switching devices of different type therein. A control circuit is provided, which is configured to drive the first and second devices with respective first and second control signals having first and second unequal duty cycles, respectively, when the first and second devices are supporting a forward current in a first current range. The control circuit is further configured to drive the first and second devices with respective third and fourth control signals having third and fourth unequal duty cycles, respectively, when the first and second devices are supporting a forward current in a second current range outside the first current range. The first duty cycle may be greater than the second duty cycle and the third duty cycle may be less than the fourth duty cycle.

Abstract: Power is provided from a power source and a status of the power source is signaled by controlling a waveform of an AC voltage generated from the power source. The status may include, for example, a capacity of the power source. In some embodiments, a frequency of the AC voltage may be controlled to signal the status. The power source may include, for example, an uninterruptible power supply (UPS), and signaling a status of the power source may include controlling an inverter of the UPS to signal the status. Related systems are also described.

Abstract: A load control device includes an input and an output connectable to an AC source and an AC load, respectively, with one or more supply lines each corresponding to a phase in the load connecting the input and output. Line-side switches are connected between a line terminal and load terminal, and floating-neutral side switches are connected to the load terminal at one end and at a common neutral connection at another end. A controller determines a direction of current flow on each of the supply lines, determines a switching pattern for each of the line-side switches and each of the floating-neutral side switches based on the determined direction of current flow, and causes each of the line-side switches and floating-neutral side switches to operate in an On condition or an Off condition according to the determined switching pattern, such that a controlled uninterrupted current is provided to the AC load.

Abstract: A system and method for selectively connecting photovoltaic (PV) arrays of a PV power system in series and parallel arrangements is disclosed. A DC-to-AC power inverter in the PV power system is electrically coupled to a plurality of PV arrays to receive a DC output therefrom and invert the DC output to an AC output, with the DC-to-AC power inverter including a DC link that receives the DC output from the plurality of PV arrays. A contactor arrangement is positioned between the plurality of PV arrays and the DC-to-AC power inverter, with the contactor arrangement including a plurality of contactors that are switchable between an on state and an off state to selectively connect the plurality of PV arrays to the DC-to-AC power inverter in a specified arrangement, so as to control a level of DC voltage received by the DC-to-AC power inverter from the plurality of PV arrays.

Abstract: A system and method for controlling switching in an AC-AC converter is disclosed. A controller for the AC-AC converter determines a direction of current flow on supply lines that provide AC power to the AC-AC converter and determines a switching pattern for each of a plurality of line-side switches and each of a plurality of floating-neutral side switches in the AC-AC converter based on the determined direction of current flow on each of the supply lines. The controller causes the line-side switches and the floating-neutral side switches to operate in an ON or OFF condition according to the determined switching pattern, such that a controlled current flow is output from the AC-AC converter. The controller also implements a safe-switching routine when transitioning from a first switching pattern to a second switching pattern that prevents a non-zero current from being interrupted during the transitioning between the first and second switching patterns.