Abstract: A power converter includes a plurality of semiconductor switching devices coupled in a parallel configuration and positioned proximate each other in an interlaced configuration with respect to a plurality of electrical phases. The interlaced configuration facilitates inducing an electric current flow through each semiconductor switching device of the plurality of semiconductor switching devices that cancels at least a portion of current imbalances between at least a portion of the plurality of semiconductor switching devices.

Abstract: A control system includes a fundamental control unit, first and second compensation control units, a switch control unit, and a switch implementation unit. The fundamental control unit generates fundamental commands to implement fundamental power conversion operation for a converter. The first compensation control unit generates a first compensation signal for injection into the fundamental command to balance neutral point voltage when the converter is in operation in a first state. The second compensation control unit generates a second compensation signal for injection into the fundamental command to balance neutral point voltage when the converter is in operation in a second state. The switch control unit detects first and second states of the converter and provides first and second switch signals respectively.

Abstract: Systems, methods, and apparatus for providing a dynamic break and distortion filter. In one embodiment, an apparatus can include an inverter providing alternating current (AC) power at one of a first and second chopping frequency and a filter. The filter can include an input port receiving the AC power and an output port providing output power by selectively passing the AC power from the input port to the output port. The filter may further include an inductor electrically connected to one of the input port and output port and a capacitor electrically connected to the inductor and to a resistor, wherein current does not substantially flow through the inductor and capacitor at the first chopping frequency and does substantially flow through the inductor and capacitor at the second chopping frequency, and wherein the AC power with the second chopping frequency is dissipated in the resistor.

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: 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: An energy storage system for use in a renewable energy power system is provided. More particularly, an energy storage system can be coupled to the DC bus of a power converter in a renewable energy power system. A switching power supply can be coupled between the energy storage device and the DC bus of the power converter. The switching power supply can include a bi-directional resonant DC to DC converter. The bi-directional resonant converter can include a plurality of switching elements, a resonant circuit coupled to the at least one switching element, and a filtering circuit coupled to the resonant circuit. The bi-directional resonant converter can be configured to accommodate power flow in at least two directions.

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: A power converter and a method for improving the output power of the power converter. The method includes independently selecting different gate resistor characteristics for the upper switching element and the lower switching element in the switching modules of the power converter to improve switching performance of both the upper and the lower switching element across a wide range of operating conditions, such as different voltages, currents, and/or operating temperatures.

Abstract: High performance gate drives and methods for driving semiconductor switching elements, such as insulated gate bipolar transistors (IGBTs), are provided. The gate drive can control the voltage applied to the gate of the IGBT to one or more intermediate voltages near the threshold voltage of the IGBT to control dv/dt of the collector-emitter voltage during and the di/dt of the collector current turn off. For instance, a voltage level between the turn on voltage and the turn off voltage can be applied for a first time period to control dv/dt of the collector-emitter voltage and di/dt of the collector current during turn off. Another voltage level between the turn on voltage and the turn off voltage can be applied for a second time period during reverse recovery of a freewheeling diode coupled in parallel with the IGBT.

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 system for regulating semiconductor devices may include a current regulator configured to regulate one or more currents provided to an insulated gate bipolar transistor (IGBT). The current regulator may regulate the currents by generating a current profile based at least in part on a collector voltage value associated with the IGBT, a rate of collector voltage change value associated with the IGBT, or any combination thereof. The current profile may include one or more current values to be provided to a gate of the IGBT such that the current values are configured to limit the rate of collector voltage change to a first value. The current regulator may then send the one or more current values to a current source configured to supply the gate of the IGBT with one or more currents that correspond to the one or more current values.

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: Systems and methods for reducing current imbalance between parallel bridge circuits used in a power converter of a doubly fed induction generator (DFIG) system are provided. A control system can monitor the bridge current of each of the bridge circuits coupled in parallel and generate a feedback signal indicative of the difference in bridge current between the parallel bridge circuits. Command signals for controlling the bridge circuits can then be developed based on the feedback signal to reduce current imbalance between the bridge circuits. For instance, the pulse width modulation of switching devices (e.g. IGBTs) used in the bridge circuits can be modified to reduce current imbalance between the parallel bridge circuits.

Abstract: Magnetic components that can be used to provide normal mode and common mode inductance in a power system, such as a wind-driven doubly fed induction generator system, are provided. The magnetic components can include a structure that combines both normal mode inductors and common mode inductors on a common core. In particular, the magnetic components can include specific winding and core arrangements which couple a common mode inductor and a normal mode inductor onto a single core with at least three legs. The structure of the magnetic components can be smaller in size, can have lower weight, and can have a lower cost than typical solutions to providing common mode and normal mode inductance in a power system.

Abstract: In one aspect, a method of galvanic isolation for a gate-controlled device is described. One embodiment of the method comprises receiving, by a gate-controlled device, wireless receive signals, wherein said wireless receive signals are received by a wireless receiver associated with the gate-controlled device.

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: An apparatus and method for improved current shunt sensing in an electrical system, such as a renewable energy electrical system, is disclosed. A current shunt according to aspects of the present disclosure includes a conductive portion that is placed in series with an electrical system The current shunt includes a sensing element that is used to measure the voltage across the conductive portion of the current shunt. The sensing element has an increased width relative to the width of the conductive portion of the shunt. The increased width of the sensing element provides for improved current shunt sensing that results in more accurate voltage (and thus current) measurements across a wide range of frequencies.

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 power conversion system for providing power to an electrical grid is described. The power conversion system includes a power converter coupled to a photovoltaic (PV) array and configured to control a PV array voltage. The power conversion system also includes a system controller communicatively coupled to the power converter and configured to select from a first reduced power operating point and a second reduced power operating point when a power available from the PV array is greater than a rated output power of the power conversion system.

Abstract: The present subject matter is directed to apparatus and methods for producing a variable frequency output waveform from a power converter for use in a power generation system, such as a wind turbine power generation system. A voltage divider is employed to provide plural voltage levels to which a multi-level bridge circuit employing selectively activated switches in pairs of switches is coupled. The switches are operated in such a fashion as to produce a generally sinusoidal waveform that may be easily filtered by low cost filters due to the plural voltage levels to produce a generally smooth sine wave from the converter. Such converters may be used in various environments including in pairs in multi-phase power converters.