Abstract: A gate drive circuit for applying a voltage to a gate of a semiconductor switching device is disclosed. The gate drive circuit includes a gate drive controller that provides voltage commands for operating the semiconductor switching device, a plurality of primary gate resistors coupled between the gate drive controller and the semiconductor switching device, one or more secondary gate resistors connected in parallel with the primary gate resistors, a primary transistor connected in series with each of the primary gate resistors, and a secondary transistor connected in series with each of the secondary gate resistors. Further, one of the primary or secondary transistors receives the one or more voltage commands from the gate drive controller and provides one or more corresponding voltage levels to the semiconductor switching device via one of the primary or secondary gate resistors so as to control the on-off behavior of the semiconductor switching device.

Abstract: A dynamic braking system for an electric power system includes a switching device coupled to an electrical conductor. The switching device is configured to open and close with a plurality of predetermined frequencies. The dynamic braking system also includes an inductive device coupled to the switching device. The power losses of the inductive device are at least partially a function of the plurality of predetermined frequencies. The dynamic braking system further includes a dynamic braking controller coupled to the switching device. The dynamic braking controller is configured to open and close the switching device with at least one of the predetermined frequencies to dissipate electric power from the electrical conductor at a predetermined rate by regulating the power losses of the inductive device as a function of the predetermined frequencies.

Abstract: In one aspect, a method for controlling the operation of switching elements contained within a single-phase bridge circuit of a power convertor may include monitoring gate voltages of a first switching element and a second switching element of the single-phase bridge circuit and controlling the first and second switching elements so that each switching element is alternated between an activated state and a deactivated state. In addition, the method may include transmitting a gating command signal to adjust the first switching element from the deactivated state to the activated state when: a first gate drive command is received that is associated with switching the first switching element to the activated state; a second gate drive command is received that is associated with switching the second switching element to the deactivated state; and the gate voltage of the second switching element is less than a predetermined voltage threshold.

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: A system is provided that includes a plurality of power units each configured to supply power. Additionally, the system includes a plurality of contacts each configured to toggle an electrical connection of each of the plurality of power units as a network. Moreover, the network is configured to supply power to a load. Furthermore, the system includes a controller configured to control when each of the plurality of contacts toggle according to a power state, and the power state includes information regarding a charge of each power unit, a load demand, and a supplied power being supplied by the plurality of power units.

Abstract: A system for operating a power generation system within a battery storage/discharge mode includes a power convertor having a DC link, a switching module coupled to the DC link, a storage device, and a filter coupled between the storage device and power converter. The filter may correspond to a normal mode filter configured to limit normal mode voltage from being applied to the storage device. A common mode filter may be associated with the storage device. The storage device may correspond to one or more batteries while the power generation system may correspond to a wind-driven generator.

Abstract: Systems and methods for cooling one or more electrical components of a current conversion device of a renewable energy power system (e.g. a wind turbine or a solar power system) are disclosed. In one embodiment, the system includes an immersion tank comprising a cooling medium, a heat exchanger, and a pumping device. One or more of the electrical components are at least partially submerged within the cooling medium, which has a predetermined dielectric constant. The heat exchanger is in fluid communication with the cooling medium of the immersion tank. Thus, the pumping device is configured to circulate the cooling medium between the immersion tank and the heat exchanger to remove heat from the one or more electrical components.

Abstract: In one aspect, the present subject matter discloses a method for overvoltage protection of an electrical system. The method may generally include detecting an overvoltage condition on an electrical system; and switching on, in response to the detected overvoltage condition, an impedance connected to the electrical system, wherein the impedance clamps voltage on the electrical system.

Abstract: An electrical power generating system including a power generating device, a power converter connected to the power generating device, and an electrical controller connected to the power converter. The electrical controller is configured to limit a peak junction temperature of the power converter by applying at least one junction temperature derating function.

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: Systems and methods for converting power are presented. The power conversion includes conducting load current through a first current path of multiple current paths in a power conversion unit using switches, diodes, or a combination thereof. The power conversion also includes blocking one or more additional current paths of the multiple current paths in the power conversion unit using one or more of the switches, one or more of the diodes, or a combination thereof. Furthermore, the power conversion includes reducing potential voltage stress on the one or more switches by using one or more voltage stress reduction switches to reduce a voltage that is blocked by the one or more blocking switches or diodes by connecting an end of each of the one or more switches opposite to a blocking edge to an intermediate voltage node.

Abstract: In one aspect, a system for operating a power generation system within a battery storage/discharge mode or a dynamic brake mode may generally include a power convertor having a DC link, a switching module coupled to the DC link and a selector switch configured to selectively couple the switching module to one of a storage device or a resistive element of the power generation system. The selector switch may be movable between a first position, wherein the switching module is coupled to the storage device such that power is capable of being directed between the DC link and the storage device via control of the switching module, and a second position, wherein the switching module is coupled to the resistive element such that power is capable of being directed between the DC link and the resistive element via control of the switching module.

Abstract: A method for controlling a power generation system connected to a weak grid may generally include operating a power converter of the system so as to produce current at or above a power factor threshold associated with a power factor operating requirement for the system, detecting that a generator speed of the system has increased over a period of time, detecting that a local reference voltage for the system has decreased within the same period of time over which the generator speed has increased and adjusting the operation of the power converter to produce current at a reduced power factor below the power factor threshold so as to increase a real power output of the system.

Abstract: A system and method for estimating a remaining life period for a device. The system includes a sensor coupled to the device, wherein the sensor is configured to facilitate measuring an operating parameter of the device and generate a measurement signal that is representative of the operating parameter. The system includes a database comprising an upper limit value, a lower limit value and a reference parameter. A processor of system includes circuitry coupled to the sensor and coupled to the database The processor is configured to correlate measurements of the operating parameter with the reference parameter to facilitate estimating a remaining life period of the device.

Abstract: A device includes a first thyristor element configured to be coupled to a first voltage line and a second voltage line, wherein the first voltage line is configured to transmit power in a first phase and the second voltage line is configured to transmit power in a second phase. The device includes a second thyristor element configured to be coupled to the second voltage line and a third voltage line, wherein the third voltage line is configured to transmit power in a third phase. The device includes a third thyristor element configured to be coupled to the first voltage line and the third voltage line.

Abstract: Renewable energy power systems, DC to DC converters, and methods for operating energy storage systems are provided. A system includes a power converter having a DC bus, and an energy storage system coupled to the DC bus of the power converter. The energy storage system includes an energy storage device and a switching power supply coupled between the energy storage device and the DC bus of the power converter. The switching power supply includes a plurality of switching elements, and an energy storage device protection circuit coupled between the plurality of switching elements and the energy storage device, the energy storage device protection circuit including a solid state switch. The switching power supply further includes a fuse coupled to the energy storage device protection circuit.

Abstract: A power conversion system for providing power to an electrical grid is described. The system includes a power converter coupled to a direct current (DC) power source. The system also includes a contactor coupled to the power converter and the electrical grid and configured to selectively electrically couple the power converter to the electrical grid. The system also includes a system controller communicatively coupled to the power converter and the contactor and configured to close the contactor to electrically couple the power converter to the electrical grid and to activate the power converter when a DC voltage provided has remained higher than a voltage level for a length of time. The system controller is also configured to deactivate the power converter, while the contactor is maintained in the closed position, when an alternating current (AC) power output has remained lower than a power level for a length of time.

Abstract: An energy power converter system is provided. According to one embodiment, the system includes a plurality of parallel converters; a main transformer with a separate magnetic path for magnetic fields are generated in the transformer by a summation of currents coming from the plurality of parallel converters electrically coupled to the main transformer; and a converter control device electrically coupled to the plurality of parallel converters and the main transformer. The converter control device may be configured to discontinue electrical flow in the system based at least in part on detection of an electrical fault condition.

Abstract: A power converter includes a plurality of power conversion modules. At least one power conversion module includes a plurality of power conversion devices defining a three-level bridge. A first power conversion module includes four terminals including one of a positive terminal and a negative terminal, an output terminal, a first neutral terminal, and a second neutral terminal. The first neutral terminal is coupled to a direct current (DC) link and the second neutral terminal is coupled to a second power conversion module.

Abstract: Systems and methods for power conversion are disclosed. The systems and methods use generation of a plurality of power levels approximately equal to multiples of one or more power supply voltage levels along with generation of one or more intermediate power levels between levels of the plurality of power levels via spanning reactor inductors. Furthermore, the method includes generating an output signal using the generated plurality of power levels and the one or more intermediate levels.