Abstract: An integrated fault and personnel protection system and method for a multi-thread converter in a wind turbine power system is provided. The structure and method provide for system optimization, as well as, arc flash protection. Fault sensing with means of removing power applied to the converter minimizes the energy available to produce an arc flash event. Sensing and disconnects devices for the protections are provided close to the source of energy to protect more of the system. Converter controls detect, identify and isolate faults selecting the best combinations of the novel specific fault isolation devices. Components are distributed into separate physical to enhance protection.

Abstract: A system and method are provided to isolate outputs of parallel converter threads of a power system converter of a wind turbine generator by utilizing isolated power windings on the output transformer from the converter. Such isolation eliminates the circulating common mode current between the parallel converters of the wind turbine system and eliminates the need for a common mode inductor. System reliability is enhanced and total system cost is reduced.

Abstract: A system and method are provided to isolate outputs of parallel converter threads of a power system converter on a generator side of a wind turbine generator by utilizing isolated power windings on the wind turbine generator. Such isolation eliminates the circulating common mode current between the parallel converters of the wind turbine system and eliminates the need for a common mode inductor. System reliability is enhanced and total system cost is reduced.

Abstract: A zero-current, synchronous switching waveform is provided for a three-phase, wye-connected H-Bridge to power an electric motor. The switching waveform includes two notches per cycle on the switching waveform provided to each of the semiconductor switches to minimize total harmonic distortion and switching loss. Positioning of the notch with respect to the zero-current crossing is optimized to reduce switching loss and minimize total harmonic distortion.

Abstract: A 7-level wye-connected H-bridge converter that provides redundancy for continued operation when one bridge phase has failed and more particularly to a topology that includes multiple semiconductor H-bridges and a three-phase semiconductor mid-bridge. The converter may continue operation with failure of any bridge, as a three-phase, wye-connected H-bridge by bypassing the failed bridge. Individual bridges of the converter may be operated at different dc-bus voltages to maximize power output. The converter may employ synchronous gating signals for the semiconductor devices of the bridges, including a zero-current notch waveform for minimizing harmonic distortion of the output waveform.

Abstract: A topology for a three-phase, wye-connected H-bridge converter allowing continued operation when one H-bridge phase has failed by bypassing the failed H-bridge, increasing dc-bus voltage to provide the required output load voltage, and decreasing switching frequency to reduce power losses in semiconductor switches. In normal operation, the dc-bus voltage is operated at a lower voltage, improving the reliability of power semiconductor devices. When an H-bridge is bypassed, the dc-bus is operated at a higher voltage but lower effective switching frequency, reducing semiconductor losses, allowing the converter to put out more current with the same temperature rise in the power switches.

Abstract: A system and method are provided to isolate outputs of parallel converter threads of a power system converter on a generator side of a wind turbine generator by utilizing isolated power windings on the wind turbine generator. Such isolation eliminates the circulating common mode current between the parallel converters of the wind turbine system and eliminates the need for a common mode inductor. System reliability is enhanced and total system cost is reduced.

Abstract: An integrated fault and personnel protection system and method for a multi-thread converter in a wind turbine power system is provided. The structure and method provide for system optimization, as well as, arc flash protection. Fault sensing with means of removing power applied to the converter minimizes the energy available to produce an arc flash event. Sensing and disconnects devices for the protections are provided close to the source of energy to protect more of the system. Converter controls detect, identify and isolate faults selecting the best combinations of the novel specific fault isolation devices. Components are distributed into separate physical to enhance protection.

Abstract: A system and method are provided to isolate outputs of parallel converter threads of a power system converter of a wind turbine generator by utilizing isolated power windings on the output transformer from the converter. Such isolation eliminates the circulating common mode current between the parallel converters of the wind turbine system and eliminates the need for a common mode inductor. System reliability is enhanced and total system cost is reduced.

Abstract: A 7-level wye-connected H-bridge converter that provides redundancy for continued operation when one bridge phase has failed and more particularly to a topology that includes multiple semiconductor H-bridges and a three-phase semiconductor mid-bridge. The converter may continue operation with failure of any bridge, as a three-phase, wye-connected H-bridge by bypassing the failed bridge. Individual bridges of the converter may be operated at different dc-bus voltages to maximize power output. The converter may employ synchronous gating signals for the semiconductor devices of the bridges, including a zero-current notch waveform for minimizing harmonic distortion of the output waveform.

Abstract: A zero-current, synchronous switching waveform is provided for a three-phase, wye-connected H-Bridge to power an electric motor. The switching waveform includes two notches per cycle on the switching waveform provided to each of the semiconductor switches to minimize total harmonic distortion and switching loss. Positioning of the notch with respect to the zero-current crossing is optimized to reduce switching loss and minimize total harmonic distortion.

Abstract: A topology for a three-phase, wye-connected H-bridge converter allowing continued operation when one H-bridge phase has failed by bypassing the failed H-bridge, increasing dc-bus voltage to provide the required output load voltage, and decreasing switching frequency to reduce power losses in semiconductor switches. In normal operation, the dc-bus voltage is operated at a lower voltage, improving the reliability of power semiconductor devices. When an H-bridge is bypassed, the dc-bus is operated at a higher voltage but lower effective switching frequency, reducing semiconductor losses, allowing the converter to put out more current with the same temperature rise in the power switches.

Abstract: This invention relates to a dual buck converter used to reduce an unregulated high input voltage without a ground reference to a regulated output voltage. This is accomplished by coupling the inductors of two independent buck converters. The input voltage is split across the dual buck converter and the mid point is balanced by coupling the inductors and switching the two switches at the same time. The inductors are wound on a single core, with the windings magnetically coupled, to form a new coupled inductor.

Abstract: A capacitor arrangement across a direct current bus provides a high ripple current capability and high capacitance at a low cost. The circuit is used in electronic power conversion devices such as electric motor drives and inverters. A combination of film capacitors and electrolytic capacitors are used in the circuit and are placed across the dc bus. The film capacitors carry substantially all of the ripple current, while the electrolytic capacitors provide the majority of the capacitance. A resistor and a diode are used to isolate the electrolytic capacitors from the ripple current. This results in a low cost compact bus capacitor configuration.

Abstract: This disclosure relates to a power supply circuit for converting AC energy from an AC source to DC energy for powering a load. The circuit comprises first and second circuit lines and a full wave rectifier connectable to the AC source and to the circuit lines for providing a rectified input voltage on the circuit lines. An inductor is connected in one of the circuit lines and an output capacitor is connected across the circuit lines between the inductor and the load. A control switch including two power terminals and a control terminal has the two power terminals connected across the circuit lines between the inductor and the output capacitor. A sensor responsive to current flow through the inductor provides a current representative signal. A relatively high fixed frequency oscillator closes the control switch in each cycle thereof.

Abstract: This disclosure relates to a power supply circuit for converting AC energy from an AC source to DC energy for powering a load. The circuit comprises first and second circuit lines and a full wave rectifier connectable to the AC source and to the circuit lines for providing a rectified input voltage on the circuit lines. An inductor is connected in one of the circuit lines and an output capacitor is connected across the circuit lines between the inductor and the load. A control switch including two power terminals and a control terminal has the two power terminals connected across the circuit lines between the inductor and the output capacitor. A sensor responsive to current flow through the inductor provides a current representative signal. A relatively high fixed frequency oscillator closes the control switch in each cycle thereof.

Abstract: An aerospace power control system switches an aerospace load from a faulty ac power bus to a good ac power bus of two or more ac power buses if the currently connected ac power bus is about to fail. The voltage level and frequency of the power provided on the buses are monitored to determine which of the power buses are within required limits to provide power to the aerospace load. If monitoring of the currently connected ac power bus indicates that the bus is not within the required limits and may be shut down in the immediate future, the connection of the aerospace load is switched to another ac power bus which is within the required limits. The current provided to the load is monitored to determine zero-crossing points of the current with the switch from the currently connected faulty bus to a good bus being performed at a zero-crossing point of the load current. The level of the current being provided to the aerospace load is also monitored to detect a faulty load condition.

Abstract: A current variation reduction circuit for metal oxide semiconductor field effect transistors, which are controlled by the application of a drive voltage between the gate and drain terminals, includes a circuit for applying a compensation current to the gate terminal. The compensation current is of substantially equivalent magnitude and opposite polarity to current in the source to gate capacitance of the MOSFET in response to a change in the source to drain voltage of the MOSFET.

Abstract: Remote power controllers for controlling power between an external power supply and a load include output stages including MOSFETs and a drive circuit connected to supply gate voltage of a preselected magnitude to each of the MOSFETs in response to a control signal. The magnitude of the gate voltage corresponds to a predetermined maximum drain current for each of the MOSFETs, with the maximum drain current being substantially constant over the expected operating temperature range of the power controller. An overload signal representative of excessive power dissipation in the MOSFETs is sensed and a trip signal is produced when that overload signal exceeds a threshold limit. The drive circuit responds to the trip signal to remove the gate voltage signal from the MOSFETs.

Abstract: An AC solid state switch includes an inverse parallel connection of a pair of silicon controlled rectifiers. A circuit branch which includes the series connection of the main conducting paths of a pair of field effect transistors is electrically connected in parallel with the inverse parallel arrangement of silicon controlled rectifiers. Gate power sources provide continuous gate drive signals to the silicon controlled rectifiers and field effect transistors. By including the field effect transistors, voltage transients across the switch are reduced in high frequency AC power systems.