Abstract: Wind turbine systems and methods for operating wind turbine systems are provided. In one embodiment, a method includes gating on a dynamic brake switch of a dynamic brake in a wind turbine power converter when an experienced direct current (DC) bus voltage is equal to or greater than a threshold DC bus voltage. The method further includes disabling a threshold temperature rating for the dynamic brake switch when the dynamic brake switch is gated on, and gating off the dynamic brake switch when the experienced DC bus voltage is less than the threshold DC bus voltage.

Abstract: A device includes a controller configured to regulate one or more voltages applied to a gate of an insulated gate bipolar transistor (IGBT). The controller is configured to receive one or more voltage values associated with the IGBT, and generate a gating signal and transmit the gating signal to the IGBT. The gating signal is configured to activate or deactivate the IGBT. The controller is configured to generate a voltage clamping signal and transmit the voltage clamping signal to activate or deactivate an active switching device. The active switching device is configured to periodically limit the one or more voltage values associated with the IGBT based at least in part on one or more characteristics of the voltage clamping signal.

Abstract: A method and system for reducing a disturbance of an electric grid signal in a wind turbine is provided. The method includes providing a generator for the wind turbine system, and, coupling a power converter to the generator, the power converter. The power converter is configured to monitor at least one of a negative sequence component and a positive sequence component of a signal transmitted from an electric grid, determine if a disturbance exists based on the monitored signal, determine at least a portion of a magnitude of the negative sequence component of the signal, and, orient a voltage of the signal based on the determined magnitude negative sequence component to modify the instantaneous power flow through the power converter.

Abstract: A power generation system may include a generator and a power converter coupled to the generator. The power converter may include a plurality of bridge circuits coupled in parallel. Each bridge circuit may be coupled to an inductor. In addition, the power converter may include a plurality of parallel shorting devices. The shorting devices may be coupled to the bridge circuits such that an impedance of the inductors is effectively coupled between the shorting devices and the generator.

Abstract: A power converter system includes a converter, a DC link, an inverter, a damping circuit, and a control system. The converter includes an input to couple to a power generation unit and an output to provide a direct current (DC) DC power output. The DC link includes a capacitor coupled to the converter output. A voltage across the capacitor defines a DC link voltage. The inverter includes an input coupled to the DC link. The damping circuit is coupled between the converter and the inverter in parallel with the DC link capacitor. The damping circuit includes a normally closed switching device, and a resistor coupled in series with the normally closed switching device. The control system is coupled to the damping circuit and configured to control the normally closed switching device as a function of at least one operating parameter of the power converter system.

Abstract: Disclosed is a mechanical layout for a half-bride power module that is optimized for low inductance. In one embodiment, a first power module and a second power module are mounted on each side of a heat sink. An inductance cancelling bus bar is wrapped around the heat sink, the first power module and the second power module in a loop.

Abstract: A method for operating a power generation system that supplies power for application to a load is disclosed. The method may generally include receiving, at a power converter, an alternating current power generated by a generator operating at a speed that is substantially equal to its synchronous speed and converting, with the power converter, the alternating current power to an output power, wherein the power converter includes at least one switching element. In addition, the method may include receiving a control command to control a switching frequency of the at least one switching element and adjusting the switching frequency to an adjusted switching frequency that is substantially equal to a fundamental frequency of the load.

Abstract: A method for operating a power generation system that supplies power for application to a load is disclosed. The method may generally include receiving, at a power converter, an alternating current power generated by a generator operating at a speed that is substantially equal to its synchronous speed and converting, with the power converter, the alternating current power to an output power, wherein the power converter includes at least one switching element. In addition, the method may include receiving a control command to control a switching frequency of the at least one switching element and adjusting the switching frequency to an adjusted switching frequency that is substantially equal to a fundamental frequency of the load.

Abstract: The present subject matter is directed to systems and methods for controlling variable speed generators, particularly converters associated with doubly-fed induction generators (DFIG) to permit use of harmonic attenuating filters that are generally smaller and less costly than previous similar filters. The subject matter provides for controlling line-side and rotor-side converters in such a manner that the frequencies generated by the converters are interleaved in a manner that the filters see a higher switching frequency and thus may be designed based on those higher frequencies, thereby requiring smaller and less expensive components.

Abstract: The present subject matter is directed to systems and methods for improving reliability of dual bridge doubly fed induction generators (DFIGs) by reducing the number of required components in the converters associated with such DFIGs. A converter is constructed using a pair of current conducting bridges wherein one of the current conducting bridges is controlled and the second is not controlled. The uncontrolled bridge may correspond to a pair of diodes while the controlled bridge may correspond to a pair of transistors, in particular, a pair of IGBT transistors.

Abstract: A control scheme for reducing current imbalance between parallel bridge circuits in a power converter system is provided. The power converter can include a plurality of bridge circuits coupled in parallel to increase the output power capability of the power system. The parallel bridge circuits can be controlled pursuant to a control scheme for reducing current imbalance between the parallel bridge circuits. In particular, a pulse test can be performed in which a pulse is applied to each of the plurality of bridge circuits. The switch timing of the switching elements responsive to the pulse can be measured and analyzed to determine a timing difference adjustment for one or more of the switching elements of the plurality of bridge circuits. The timing difference adjustment can be stored and used to adjust all subsequent switching events in the parallel bridge circuits.

Abstract: A connection for parallel bridge circuits in a power converter is provided. In particular, a power converter can be used to provide a desired power to a load, such as a generator, motor, electrical grid, or other suitable load. The power converter can include a plurality of bridge circuits coupled in parallel. A bridge output of each of the parallel bridge circuits can be coupled together at the load instead of at the power converter. In particular, the parallel bridge circuits can be coupled together at a location that is physically proximate the physical location of the load, such as at a plurality of terminals associated with the load. By doing so, stray inductance associated with conductors used to couple the bridge outputs of the parallel bridge circuits to the load can be effectively coupled between the parallel bridge circuits.

Abstract: Systems and methods for reducing current imbalance between parallel bridge circuits used in a power converter of a power generation system, such as a wind driven doubly fed induction generator (DFIG) system, are provided. The power converter can include a plurality of bridge circuits coupled in parallel to increase the output power capability of the system. Each of the bridge circuits can include a pair of switching elements, such as insulated gate bipolar transistors (IGBTs), coupled in series with one another. The switching elements of the parallel bridge circuits can be controlled, for instance, using control commands (e.g. pulse width modulation commands) according to a substantially non-interleaved switching pattern. The timing of the control commands according to the substantially non-interleaved switching pattern can be adjusted to reduce current imbalance between the parallel bridge circuits.

Abstract: Certain embodiments of the invention may include systems, methods and apparatus for voltage clamp circuits. According to an example embodiment of the invention, a voltage clamp circuit may include a first circuit portion electrically coupled to the output of at least one power source. The first circuit portion comprises a power semiconductor device having a first, second and a third node and one or more zener diodes electrically coupled to the first or the second node of the power semiconductor device. The voltage clamp circuit may further include a second circuit portion in electrical communication with the first circuit portion, where the second circuit portion comprises a resistor, a capacitor and a directional device, and where the second circuit portion connects to the one or more zener diodes to reduce peak voltage output between the second and the third node of the power semiconductor device.

Abstract: A power conversion system for providing power to an electrical grid is described. The power conversion system includes a power converter coupled to a power source and the electrical grid. The power conversion system also includes a converter controller coupled to the power converter and configured to control operation of the power converter to actively cancel harmonic current received at the power converter from the electrical grid.

Abstract: A device includes a controller configured to regulate one or more voltages applied to a gate of an insulated gate bipolar transistor (IGBT). The controller is configured to receive one or more voltage values associated with the IGBT, and generate a gating signal and transmit the gating signal to the IGBT. The gating signal is configured to activate or deactivate the IGBT. The controller is configured to generate a voltage clamping signal and transmit the voltage clamping signal to activate or deactivate an active switching device. The active switching device is configured to periodically limit the one or more voltage values associated with the IGBT based at least in part on one or more characteristics of the voltage clamping signal.

Abstract: Systems and methods for controlling battery charging are disclosed. According to one embodiment of the disclosure, a method can include receiving battery state information; determining, based on the battery state information, whether to adjust battery models; and, if so, adjusting the battery models.

Abstract: The present subject matter is directed to systems and methods for improving reliability of dual bridge doubly fed induction generators (DFIGs) by reducing the number of required components in the converters associated with such DFIGs. A converter is constructed using a pair of current conducting bridges wherein one of the current conducting bridges is controlled and the second is not controlled. The uncontrolled bridge may correspond to a pair of diodes while the controlled bridge may correspond to a pair of transistors, in particular, a pair of IGBT transistors.

Abstract: A control system for determining a desired mission is provided. The control system includes an interface for receiving a mission input and a control module. The control module is in communication with the interface, and determines the desired mission. The desired mission represents a specific conclusion based on analyzing data located in at least one database. The control module includes a transform avatar for determining a proposed transform based on the mission input. The proposed transform is a defined set of rules to determine the desired mission based on the data located in at the least one database. The control module includes a calculation avatar receiving the proposed transform. The calculation avatar analyzes the data located in the at least one database based on the proposed transform to determine the desired mission.

Abstract: A method for detecting a grid event is provided. The method includes sampling grid voltage and grid current over a fixed period of time; determining grid impedance at one or more frequencies using the sampled grid voltage and the sampled grid current; comparing the grid impedance at the one or more frequencies to a known expected grid impedance at the one or more frequencies; and detecting a grid event based on the comparison.