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:
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.
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 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 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:
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:
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 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. The switch implementation unit switches the fundamental control unit to communicate with the first and second compensation control units according to the first and second switch signals respectively.
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:
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.