Abstract: A power conversion system includes a first converter effectively connected in series to a second converter. Each converter has a plurality of output levels. A phase-shifted transformer is coupled to the converters. The phase-shifted transformer has a delta-wound winding and an open star winding. The first converter is coupled to the open star winding and the second converter is coupled to the delta winding. The open star winding is configured for direct connection to either of a load or the open star winding of a second phase-shifted transformer, having a delta winding connected to a third converter. One or more DC voltage sources are each connected to the first and second converters by a respective DC link capacitor. Each DC voltage source is connected to a common power grid by an isolated multiphase transformer winding.

Abstract: A system for converting a first electric voltage into a second electric voltage, comprising: at least two input terminals and two output terminals; and switching members disposed between the terminals, which can convert the first voltage into the second voltage. At least one switching member comprises at least two arms connected in parallel and each arm includes an electronic switch that can be controlled such as to occupy either an on-state or an off-state, said switch comprising a control electrode and two conduction electrodes that conduct current in the on-state. The switching member comprises a common control terminal connected to the control electrode of the switch of each arm, as well as a first common conduction terminal and a second common conduction terminal connected respectively to a first conduction electrode and a second conduction electrode of the switch of each of the arms.

Abstract: An assembly includes an insulated gate bipolar transistor (IGBT), a gate driver and a short-circuit protection circuit. The gate driver is adapted to supply voltage to a gate terminal of the IGBT. The short-circuit protection circuit includes an IGBT short-circuit detector for determining whether the IGBT is short-circuited, and a supply voltage regulator for regulating the supply voltage in response to the IGBT short-circuit detector determining that the IGBT is short-circuited.

Abstract: A grid-side transformerless power conversion system configured to perform power conversion between a power grid and a load, the transformerless power conversion system includes a first converter, a first filter, and a second converter. The first converter is configured to convert first AC power provided from the power grid into DC power. The first converter includes a first converter module and a second converter module coupled to the first converter module to form a nested neutral point piloted topology. The first filter is coupled between the power grid and the first converter. The second converter is coupled to the first converter. The second converter is configured to convert the DC power into second AC power and provide the second AC power to the load.

Abstract: A method is described for controlling a plurality of parallel-connected power converters 20a, 20b, each of which operates in accordance with a pulse width modulation (PWM) strategy defined by an independent voltage carrier signal and an independently controllable modulating sinusoidal voltage signal which are used to generate a PWM command signal for each PWM strategy. The voltage carrier signals of the PWM strategies have the same switching period and desynchronisation of the PWM command signals causes an unwanted circulating current to flow between the power converters 20a, 20b. The method thus comprises providing the independently controllable modulating sinusoidal voltage signal of the PWM strategy of at least one of the plurality of power converters 20a, 20b with a dc voltage offset to modify the PWM command signal of the at least one power converter and thereby increase the synchronisation of the PWM command signals so that the magnitude of any unwanted circulating current is reduced.

Abstract: A wind turbine generator has a drive end at which one or more turbine blades are mountable and a non-drive end. The wind turbine generator comprises an external stator having a radially inner surface and an internal rotor having a radially outer surface, an air gap being defined between the rotor and the stator. A main bearing arrangement is provided at the drive end and acts between the rotor and the stator to mount the rotor for rotation about the stator and a stabiliser bearing is provided at the non-drive end and acts between the rotor and the stator to stabilise the rotor and stator and maintain and control the air gap therebetween.

Abstract: The present invention relates to a vertical axis wind turbine having a vertical support tower. At least one aerofoil or blade is mounted for rotation about the support tower. An electrical machine, typically a permanent magnet generator includes a rotor assembly and a stator assembly. The at least one aerofoil is secured to the rotor assembly such that rotation of the aerofoil about the support tower causes rotation of the rotor assembly relative to the stator assembly. The stator assembly is formed as a structural component of the support tower and defines part of a vertical access passage that extends through the support tower to provide access for maintenance and repair.

Abstract: A rotor (or a stator) for a superconducting electrical machine includes a mounting that is maintained at substantially ambient temperature during operation of the electrical machine and a field coil support structure. A plurality of superconducting field coils are maintained at cryogenic temperatures during operation of the electrical machine and are supported by the field coil support structure. At least one coupling element is used to fix the field coil support structure to the mounting. The field coil support structure is preferably fixed to the mounting by a plurality of substantially circumferentially extending coupling elements at a first and second axial end of the field coil support structure and the mounting such that the mounting and field coil support structure are substantially separated over their axial lengths by a vacuum gap.

Abstract: The present invention relates to power distribution systems (e.g. a marine power distribution and propulsion system) that include first and second ac distribution busbars. The first ac distribution busbar will typically be a medium voltage busbar for the propulsion drive systems and the second ac distribution busbar will typically be a low voltage for ships services. A 12-pulse rectifier has its ac terminals electrically connected to the first ac distribution busbar. A multiple output generator has first and second galvanically-isolated stator windings. The first stator winding provides a six-phase ac output and is connected to the first ac distribution busbar. The second stator winding provides a three-phase ac output and is connected to the second ac distribution busbar. The six-phase ac output is phase shifted relative to the three-phase ac output to reduce the problematic coupling of harmonic distortion between the first and second ac distribution busbars.

Abstract: A torsional vibration damper is integrated into a rotating electrical machine. A rotatable assembly of the electrical machine includes a rotor core pack having a first end and a second end, The integrated torsional vibration damper consists of a torsional elastic coupling and a torsional elastic damper and provides mechanical damping. The integrated torsional vibration damper is mounted to the rotatable shaft of the electrical machine by a flange. The rotor core pack is mounted at the first end to the integrated torsional vibration damper by suitable structure members such as a mounting flange and is not fixedly mounted directly to the rotatable shaft. In the case where the rotor core pack is cooled by circulating coolant fluid (e.g. MIDEL) then the integrated torsional vibration damper may be a viscous damper that uses the coolant fluid as a viscous working, fluid.

Abstract: Described is a method for operating a power semiconductor component. A power amplifier provided with a programmable logic is assigned to this power semiconductor component. In at least one embodiment, control signals for the power semiconductor component are transmitted to the power amplifier. The power semiconductor component is influenced by the power amplifier in dependence on these control signals. The type and manner in which the power semiconductor component is influenced is determined by the programming of the logic. The power amplifier can be sent programming signals which are then processed by a processor of the power amplifier. The programming of the logic is changed by the processor in dependence on the programming signals.

Abstract: In one embodiment of the present invention, a multiphase electric circuit is disclosed for shutting down a current conducted over respectively one AC power controller. The neutral points of the voltage systems connected to the phases are not connected to each other via a neutral conductor. The AC power controller of each phase is provided with two thyristors. A single series connection is connected parallel to all phases, which series connection comprises a capacitor and a number of parallel-connected quenching switches corresponding to the number of phases. The capacitor can be charged up via a diode bridge and a transformer.

Abstract: A method of driving a number of series connected active power semiconductor groups, wherein each of the active power semiconductor groups includes one or more gate oxide-isolated active power semiconductor devices. The method includes generating a current pulse, providing the current pulse to a primary portion of a transformer unit and in response thereto causing a number of reflected current pulses to be reflected at a secondary portion of the transformer unit, and transferring and latching each of the reflected current pulses to create a respective latched gate drive signal, and providing each respective latched gate drive signal to an associated one of the active power semiconductor groups for driving the one or more gate oxide-isolated active power semiconductor devices of the associated one of the active power semiconductor groups. Also, a gate drive circuit that implements the method.

Abstract: An electronic system includes a master module having a first control unit having one or more first serial interfaces and being programmed to output a first data signal and a first clock signal through the one or more first serial interfaces, and a slave module having a second control unit, the second control unit having a second serial interface. The slave module receives the first clock signal through the second serial interface, and the second control unit is programmed to monitor the slave module for a fault condition and output a second clock signal through the second serial interface which is (i) the same as the first clock signal if a fault condition on the slave module is not detected, and (ii) a modified clock signal having a predetermined format through the second serial interface if a fault condition on the slave module is detected.

Abstract: A hybrid conditioner for filtering harmonics in a power system that includes a non-linear load. The hybrid conditioner includes an active filter structured and controlled to filter one or more high-order harmonic currents of the fundamental frequency, and a passive filter structured to filter one or more low-order harmonic currents of the fundamental frequency. The active filter and the passive filter are electrically connected in parallel with one another. The hybrid conditioner may also be for providing reactive power compensation for the power system, wherein the active filter is further controlled to provide a compensatory reactive power for compensating for the reactive power that is consumed by the load. The hybrid conditioner may also provide oscillation dampening for the power system, wherein the active filter is further controlled to damp oscillating currents that exist between the passive filter and the AC source.