Abstract: Photovoltaic (PV) array emulators and methods are described. In one example, a method for use in testing a PV inverter includes coupling a first PV inverter to an alternating current (AC) power source. A second PV inverter is coupled to receive an output of the first PV inverter. The first PV inverter is operated to emulate a PV array and provide a DC power output to the second PV inverter.

Abstract: A method of providing reactive power support is proposed. The method includes detecting at least one of a plurality of network parameters in a distributed solar power generation system. The generation system includes a plurality of photovoltaic modules coupled to a grid via inverters. The method further includes sensing a state of the photovoltaic modules coupled to the distributed solar power generation system and determining a reactive power measure based upon the sensed state and the detected network parameters. The reactive power measure is used to generate a reactive power command. The reactive power command is further used to compensate reactive power in the distributed solar power generation system.

Abstract: A control system for controlling a multiphase power converter includes a current control module, a voltage control module and a current command selector. The current control module generates grid voltage command signals for the multiphase power converter and the voltage control module generates reference converter current command signals for the current control module. The current command selector supplies active and reactive current command signals from a supervisory controller to the current control module when the multiphase power converter is connected to the grid and supplies the reference converter current command signals to the current control module when the multiphase power converter is unconnected to the grid.

Abstract: A gradient amplifier system is presented. An embodiment of a gradient amplifier system that includes a power stage having a plurality of bridge amplifiers, where each of the plurality of bridge amplifiers operates at a first switching frequency. The gradient amplifier system further includes a gradient coil coupled to an output terminal of the power stage and configured to produce a magnetic field proportional to a coil current signal supplied by the power stage. In addition, the gradient amplifier system includes a controller stage coupled to an input terminal of the power stage and configured to generate a pulse width modulated gate signal based on the coil current signal and a reference current signal, where the pulse width modulated gate signal is generated at a second switching frequency upon occurrence of a slew rate associated with the reference current signal is below a determined threshold rate and an amplitude level associated with the reference current signal is above a determined level.

Abstract: An alternating current to direct current (AC to DC) power conversion system is provided. The system includes a rectifier configured to convert an input AC voltage to an initial pulsating DC voltage. The system also includes an inverter configured to convert the initial pulsating DC voltage to a converted AC voltage. The system further includes a plurality of transformers, each transformer including a primary winding paired to a secondary winding, wherein each of the primary windings is coupled in series with the other primary windings, wherein the series coupled primary windings are coupled to the inverter to receive respective portions of the converted AC voltage. The system also includes a plurality of bridges, each bridge coupled to a respective secondary winding configured to receive a respective portion of a transformed AC voltage from the respective secondary windings, and coupled in parallel to the other bridges to provide a combined DC output voltage.

Abstract: An alternating current to direct current (AC to DC) power conversion system is provided. The system includes a rectifier configured to convert an input AC voltage to an initial pulsating DC voltage. The system also includes an inverter configured to convert the initial pulsating DC voltage to a converted AC voltage. The system further includes a plurality of transformers, each transformer including a primary winding paired to a secondary winding, wherein each of the primary windings is coupled in series with the other primary windings, wherein the series coupled primary windings are coupled to the inverter to receive respective portions of the converted AC voltage. The system also includes a plurality of bridges, each bridge coupled to a respective secondary winding configured to receive a respective portion of a transformed AC voltage from the respective secondary windings, and coupled in parallel to the other bridges to provide a combined DC output voltage.

Abstract: A bidirectional buck-boost power converter 13 including a pair of inverter modules 14, 15 disposed at an output of a machine, and an inductor Lo connected between the pair of inverter modules 14, 15. A method for controlling a voltage output of a machine starter generator having an inverter rectifier and bidirectional buck-boost converter, includes outputting a dc voltage controlled by bidirectional buck-boost pulse width modulation (PWM) switching control, when the starter generator is in a generator mode.

Abstract: The disclosed technology is a cryogenic static exciter. The cryogenic static exciter is connected to a synchronous electric machine that has a field winding. The synchronous electric machine is cooled via a refrigerator or cryogen like liquid nitrogen. The static exciter is in communication with the field winding and is operating at ambient temperature. The static exciter receives cooling from a refrigerator or cryogen source, which may also service the synchronous machine, to selected areas of the static exciter and the cooling selectively reduces the operating temperature of the selected areas of the static exciter.

Abstract: A control system for controlling a multiphase power converter includes a current control module, a voltage control module and a current command selector. The current control module generates grid voltage command signals for the multiphase power converter and the voltage control module generates reference converter current command signals for the current control module. The current command selector supplies active and reactive current command signals from a supervisory controller to the current control module when the multiphase power converter is connected to the grid and supplies the reference converter current command signals to the current control module when the multiphase power converter is unconnected to the grid.

Abstract: A system for controlling a microgrid includes microgrid assets and a tieline for coupling the microgrid to a bulk grid; and a tieline controller coupled to the tieline. At least one of the microgrid assets comprises a different type of asset than another one of the microgrid assets. The tieline controller is configured for providing tieline control signals to adjust active and reactive power in respective microgrid assets in response to commands from the bulk grid operating entity, microgrid system conditions, bulk grid conditions, or combinations thereof.

Abstract: A method of providing reactive power support is proposed. The method includes detecting at least one of a plurality of network parameters in a distributed solar power generation system. The generation system includes a plurality of photovoltaic modules coupled to a grid via inverters. The method further includes sensing a state of the photovoltaic modules coupled to the distributed solar power generation system and determining a reactive power measure based upon the sensed state and the detected network parameters. The reactive power measure is used to generate a reactive power command. The reactive power command is further used to compensate reactive power in the distributed solar power generation system.

Abstract: A photovoltaic (PV) control system generates a power output rate control signal based on a monitored rate of change of collective power output generated via a plurality of PV subsystems and a desired collective output power change rate for the plurality of PV subsystems and communicates the power output rate control signal to the plurality of PV subsystems to control a rate of change of one or more operating parameters of individual PV subsystems in order to control a rate of change of collective output power of the plurality of solar PV subsystems.

Abstract: Embodiments of methods and systems of a system for simulating a plant are provided. According to one exemplary embodiment of the invention, there is disclosed a system for simulating a plant. The system may include a controller including plant operation logic for executing control commands to the plant. The system may further include a simulator in communication with the controller, where the simulator may consist of high bandwidth hardware having at least one high bandwidth model of at least a first plant behavior. The simulator may also consist of at least one processor with at least one low bandwidth model of at least a second plant behavior.

Abstract: An AC-AC Converter for an AC source which in one embodiment has a first rectifier section rectifying the AC source into a first pulsed DC link voltage signal and a high frequency modulating section coupled to the first pulsed DC link voltage signal and producing a high frequency AC voltage signal. A high frequency transformer is coupled to the high frequency AC voltage signal producing a transformed high frequency AC signal. There is a second rectifier section coupled to the transformed high frequency AC signal and producing a second pulsed DC voltage signal and an unfolder section coupled to the second pulsed DC voltage signal and producing an output AC signal.

Abstract: An electrical power generation system and method for generating electrical power are provided. The electrical power generation system utilizes a master controller for controlling operation of devices coupled to an AC electrical grid and DC electrical grid based on parameter values associated with a renewable power generator.

Abstract: Power balancing techniques for a synchronous power generation system are provided. One exemplary method for balancing power in a synchronous generator system includes determining an output power characteristic of a synchronous generator driven by a prime mover and comparing the characteristic to a value derived from the output power of a plurality of synchronous generators. The method also includes providing a correction signal to the synchronous generator to modify the output power produced by that generator. A synchronous power generation system having a plurality of synchronous generators driven by a common prime mover is also provided.

Abstract: A power conversion system includes two three-level converters, and a phase shifted transformer coupled to the converters.

Abstract: An electrical power generation system and method for generating electrical power are provided. The electrical power generation system utilizes a master controller for controlling operation of devices coupled to an AC electrical grid and DC electrical grid based on parameter values associated with a renewable power generator.

Abstract: Various embodiments relate to systems and methods related to an integrated electrically-powered sub-system and wind power system including a wind power source, an electrically-powered sub-system coupled to and at least partially powered by the wind power source, the electrically-powered sub-system being coupled to the wind power source through power converters, and a supervisory controller coupled to the wind power source and the electrically-powered sub-system to monitor and manage the integrated electrically-powered sub-system and wind power system.

Abstract: A system for controlling a microgrid includes microgrid assets and a tieline for coupling the microgrid to a bulk grid; and a tieline controller coupled to the tieline. At least one of the microgrid assets comprises a different type of asset than another one of the microgrid assets. The tieline controller is configured for providing tieline control signals to adjust active and reactive power in respective microgrid assets in response to commands from the bulk grid operating entity, microgrid system conditions, bulk grid conditions, or combinations thereof.