Abstract: A power distribution system comprises a power conversion module for performing power conversion between a DC voltage at a DC side and an AC power at an AC side, and a conversion control system. The AC side of the power conversion module is electrically coupled to a grid. The conversion control system includes a phase-locked-loop circuit for receiving a multi-phase reference signal of a grid voltage and for generating a synchronized signal, a regulator for receiving reference commands, a two-phase grid feedback signal, and the synchronized signal and for generating a control signal for the power conversion module, and a phase compensation circuit for receiving the synchronized signal and the multi-phase reference signal of the grid voltage, for obtaining a phase displacement signal, and for generating a phase compensation signal for compensating the reference commands or for compensating the synchronized signal when the phase displacement signal exceeds a threshold value.

Abstract: A solar power generation system includes a control system and a DC to AC converter coupled to a photovoltaic (PV) module and for supplying power to a power network. The control system includes a power point tracker to extract either maximum power available from the PV module or less than maximum power available from the PV module, a frequency monitor to obtain a network frequency from the power network, an internal reference frame element to provide an internal reference frequency of the solar power generation system, a frequency comparator to compare the network frequency and the internal reference frequency, and a command signal generator to use the frequency comparison to determine whether a transient increase or decrease in commanded output power is warranted and to provide a command signal.

Abstract: A power generation system comprises at least two electrical systems connected at an electrical connection point. Each electrical system comprises a power conversion system comprising a converter including a plurality of switches for converting direct current power into alternating current power. The power generation system comprises a control system including at least two pulse width modulation (PWM) modulators, each PWM modulator for obtaining a fundamental waveform and a carrier signal, using the fundamental and carrier signals to generate a PWM pattern, and for providing the PWM pattern to a respective converter for driving the switches of the respective converter. The control system is configured to interleave carrier signals, fundamental waveforms, or a combination of carrier signals and fundamental waveforms of the at least two electrical systems to generate interleaved PWM patterns respectively for the at least two converters.

Abstract: A solar farm system is provided that is configured for reducing electrical loss. The solar farm system includes a plurality of PV arrays coupled to inverters and a collector system including a conductor or network of conductors. The collector system also includes a plurality of transformers with one or more transformers connected between the inverters and the conductors. The solar farm also includes a substation transformer connecting the solar farm collector system to the electrical grid. The solar farm includes a control system configured to determine at least one operating parameter for the solar farm system to reduce electrical loss and to regulate the collector system and the plurality of inverters based at least in part on the at least one operating parameter.

Abstract: A system for controlling torque ripple in a permanent magnet synchronous machine includes a power converter configured to be coupled to the permanent magnet synchronous machine and to receive converter control signals and a system controller coupled to the power converter. The system controller includes a fundamental current controller configured for providing fundamental voltage commands, a harmonic current controller configured for using harmonic current commands, current feedback signals from the permanent magnet machine, and fundamental current commands in combination with positive and negative sequence regulators to obtain harmonic voltage commands, and summation elements configured for adding the fundamental voltage commands and the harmonic voltage commands to obtain the converter control signals.

Abstract: A system, a method, and an article of manufacture for controlling operation of an electrical power generation system are provided. The electrical power generation system has a plurality of electrical generators electrically coupled to an electrical grid. The method includes obtaining a first output parameter value associated with the electrical power generation system. The method further includes determining an error value indicative of a difference between the first output parameter value and a desired output parameter value. The method further includes determining a first gain value based on at least one of the first output parameter value and a time-varying operational parameter of the electrical power generation system. The method further includes determining a first power value based on the error value and the first gain value.

Abstract: A method and apparatus for connection of a wind driven turbine generator to an HVDC transmission line is provided that does not require transformation of the wind generated AC voltage to a nominal AC distribution grid frequency. An AC output from the turbine generator is increased in level and converted to HVDC for direct application to a HVDC transmission line. The wind turbine generated AC may be first increased in frequency via a matrix converter and then rectified or may be first rectified and increased in level by a high-voltage DC-DC converter circuit and then applied directly to the HVDC transmission line.

Abstract: A power generation system includes a rotary power generator for generating a variable-frequency alternating current, a generator side converter for converting the variable-frequency alternating current into a DC current, a DC link coupled to the generator side converter for receiving the DC current, a line side converter coupled to the DC link for converting the DC current into an alternating current with controlled amplitude or frequency, a generator side controller for receiving a DC link voltage command signal and a DC link voltage feedback signal and generating control signals for the generator side converter, and a line side controller for receiving a generator torque command signal and a generator torque feedback signal and generating control signals for the line side converter.

Abstract: A system for providing energy and other ancillary services to a power grid including a renewable energy source. One or more power converters are integrated with the renewable energy source. A battery-based energy storage system is also integrated with the renewable energy source. A control system including an algorithmic software operates to control at least one power converter together with the battery-based energy storage system to supply stored battery energy to the grid when the cost of extracting the stored battery energy supplied to the grid via the battery-based energy storage system is less than the market price paid for the stored energy supplied by the battery-based energy storage system.

Abstract: Commands are generated for controlling a state of charge of an energy storage device coupled between an energy source and an auxiliary load. Commands are also generated for providing from the energy storage device to the auxiliary load and for using power from the energy storage device for controlling a DC link voltage, energy source torque, grid side power flow, or combinations thereof. Commands may also be generated to provide frequency compatible power to auxiliary loads of the energy source.

Abstract: A method and system for reducing the cost of a combined offshore wind generation plant is provided by coupling the AC output of plural wind turbine generators to a single AC-DC converter prior to transmission of the DC power to an onshore DC-AC inverter site. The wind speed is monitored at selected locations within the wind plant, optionally, at selected turbine generators, and the operating frequency of the AC-DC converter is adjusted in accordance with a combine wind speed signal to permit operation of the plural wind turbines as a group. AC-DC followed by DC-AC conversions decouples the AC frequency produced by the wind turbines and allows the turbines to operate at variable frequency as a group.

Abstract: A phase-locked loop circuit comprises a phase error detector for receiving a multi-phase reference signal and a synchronized phase signal of the phase-locked-loop circuit, and for performing a rotational transformation to convert the multi-phase reference signal into two-phase quantities at a synchronous rotation d-q reference frame. A monotonic transfer module receives the two-phase quantities, and generates a monotonic phase error signal which is monotonic when a phase difference between the multi-phase reference signal and the synchronized phase signal ranges from ?180 degrees to 180 degrees. A regulator receives the monotonic phase error signal, and generates a synchronized rotation frequency. An integrator receives the synchronized rotation frequency, and generates the synchronized phase signal.

Abstract: A phase-locked loop circuit comprises a phase error detector for receiving a multi-phase reference signal and a synchronized phase signal of the phase-locked-loop circuit, and for performing a rotational transformation to convert the multi-phase reference signal into two-phase quantities at a synchronous rotation d-q reference frame. A monotonic transfer module receives the two-phase quantities, and generates a monotonic phase error signal which is monotonic when a phase difference between the multi-phase reference signal and the synchronized phase signal ranges from ?180 degrees to 180 degrees. A regulator receives the monotonic phase error signal, and generates a synchronized rotation frequency. An integrator receives the synchronized rotation frequency, and generates the synchronized phase signal.

Abstract: A power generation system having a wind turbine blade assembly, a generator mechanically coupled to the blade assembly, and a power converter coupled to the generator is provided. An energy storage device and a bidirectional converter coupling the energy storage device to the power converter are also provided in the system. An inertia controller is provided for generating a first transient signal to regulate active power from the wind turbine system when a power grid signal is outside of a respective signal range. The system further includes an energy storage controller for providing a second transient signal to the bidirectional converter to regulate a power to or from the energy storage device based upon the first transient signal, power generating system conditions or combinations thereof.

Abstract: A power distribution system comprises a power conversion module for performing power conversion between a DC voltage at a DC side and an AC power at an AC side, and a conversion control system. The AC side of the power conversion module is electrically coupled to a grid. The conversion control system includes a phase-locked-loop circuit for receiving a multi-phase reference signal of a grid voltage and for generating a synchronized signal, a regulator for receiving reference commands, a two-phase grid feedback signal, and the synchronized signal and for generating a control signal for the power conversion module, and a phase compensation circuit for receiving the synchronized signal and the multi-phase reference signal of the grid voltage, for obtaining a phase displacement signal, and for generating a phase compensation signal for compensating the reference commands or for compensating the synchronized signal when the phase displacement signal exceeds a threshold value.

Abstract: A system for controlling torque ripple in a permanent magnet synchronous machine includes a power converter configured to be coupled to the permanent magnet synchronous machine and to receive converter control signals and a system controller coupled to the power converter. The system controller includes a fundamental current controller configured for providing fundamental voltage commands, a harmonic current controller configured for using harmonic current commands, current feedback signals from the permanent magnet machine, and fundamental current commands in combination with positive and negative sequence regulators to obtain harmonic voltage commands, and summation elements configured for adding the fundamental voltage commands and the harmonic voltage commands to obtain the converter control signals.

Abstract: A system for controlling torque ripple in a permanent magnet synchronous machine includes a power converter configured to be coupled to the permanent magnet synchronous machine and to receive converter control signals and a system controller coupled to the power converter. The system controller includes a fundamental current controller configured for providing fundamental voltage commands, a harmonic current controller configured for using harmonic current commands, current feedback signals from the permanent magnet machine, and fundamental current commands in combination with positive and negative sequence regulators to obtain harmonic voltage commands, and summation elements configured for adding the fundamental voltage commands and the harmonic voltage commands to obtain the converter control signals.

Abstract: A system for controlling a grid connected power generating system is provided. The system includes a wind turbine, a converter, a first controller and a second controller. The wind turbine supplies electrical power to a power grid and the converter couples the wind turbine to the power grid. The first controller calculates voltage commands to emulate a phasor back electromotive force behind an inductance. The controller further generates converter switching commands from the voltage commands. The voltage commands include a voltage magnitude reference and an internal frequency reference calculated from a power imbalance between an active power reference and the electrical power. The second controller is used to limit a converter current.

Abstract: An exemplary embodiment includes a wind turbine system. The wind turbine system includes a wind turbine generator operable to supply wind turbine power to a utility system. A converter is coupled to the wind turbine generator and the utility system. The wind turbine system also includes a controller comprising an internal reference frame of the wind turbine generator, coupled to the converter, and configured for modulating flow of power through the converter in response to frequency disturbances or power swings of the utility system relative to the internal reference frame.

Abstract: A power generation system comprises at least two electrical systems connected at an electrical connection point. Each electrical system comprises a power conversion system comprising a converter including a plurality of switches for converting direct current power into alternating current power. The power generation system comprises a control system including at least two pulse width modulation (PWM) modulators, each PWM modulator for obtaining a fundamental waveform and a carrier signal, using the fundamental and carrier signals to generate a PWM pattern, and for providing the PWM pattern to a respective converter for driving the switches of the respective converter. The control system is configured to interleave carrier signals, fundamental waveforms, or a combination of carrier signals and fundamental waveforms of the at least two electrical systems to generate interleaved PWM patterns respectively for the at least two converters.