Ge Energy Power Conversion Technology Gmbh

Converteam UK Ltd.

Converteam Technology Ltd.

Alstom Power Conversion Gmbh

Cegelec Controls Limited

Converteam Gmbh

Ge Energy Power Conversion UK Limited

Allan David Crane

Martin Samuel Butcher

Teng Long

Warren Mark Blewitt

Andrew James Bullock

Paul Eaton Clark

Lihua Hu

Clive Lewis

Ushindibaba Mupambireyi

Nicholas Simon Smith

Aravazhi Anabarasu

Ramasamy Anabarasu

Martin Charles Southall

Mounir Louati

Ralph Edwin Maltby

Sean Joseph Loddick

David Hinchley

Changjiang Zhan

Jonathan Childs

Christopher John Dunne

David Nicholas Lee

Bhaskar Sen

Andrew Goldney

Provided is a switching module and a process of commutating the switching module. The switching module includes an H-bridge circuit with bidirectional switches and an active clamp with switches that are also arranged as an H-bridge. The process of commutating the switching module includes a sequence of alternating first and second commutation events where timing signals used to control the switches during each commutation event are varied according to closed loop control of the voltage across the energy storage device of the active clamp.

Switching module of a power electronic switching assembly and a process of commutating the same

A power distribution system includes power converter systems electrically connected to a distribution bus which defines a point of common coupling. Each power converter system includes a power converter with semiconductor switching devices controlled using a pulse width modulation strategy with a switching frequency. A controller for each power converter system applies a spectrum analysis process to the respective power converter system that uses measured or derived zero sequence currents associated with the respective power converter system to determine the location of a ground fault within the power distribution system. Each controller applies a switching frequency process where the switching frequency of the power converter of at least one of the power converter systems is different from the switching frequency of the power converter of at least another one of the power converter systems during at least part of the time that the spectrum analysis process is applied.

Ground fault protection methods

A method of controlling a power system that includes an electrical machine, e.g., wind turbine generator, a power converter, a DC circuit and a dynamic braking system (DBS) having a braking circuit having a braking resistor and being connected in series to the DC circuit, is provided. The method includes operating the DBS and controlling operation of the electrical machine based on a prevailing temperature of the braking circuit, stopping the electrical machine and controlling the electrical machine to be restarted at its rated output power once the prevailing temperature of the braking resistor reaches or falls below a lower temperature threshold. The electrical machine may be restarted at a lower output power and after restarting, its output power can be increased based on a power starting profile as the braking resistor cools.

Power systems

A DC/DC power converter connected to a DC power source having first and second DC terminals. The DC/DC power converter operates in voltage step-up and step-down modes. The converter includes first and second DC buses connected to the first and second DC terminals and third and fourth DC buses defining a DC link. Energy storage devices are connected between the third and fourth buses. A first converter leg includes a first branch with switches and a second branch. Each switch includes a controllable semiconductor switch and an anti-parallel connected freewheeling diode. A controller switches the controllable semiconductor switches between a conducting and non-conducting state, in the step-up and step-down modes, switching to supply power from the DC power source to the DC link in the step-up mode and to supply power from the DC link to the DC power source in the step-down mode.

DC-DC power converters with step-up and/or step-down mode(s)

A power converter arrangement is described. The power converter includes a dc link and a power converter. The dc link is operably connected between a generator, or other power source, that provides an output voltage in use and a dc network. The power converter includes an inverter connected across the dc link in parallel with the generator, an isolation transformer having a primary tap changer and a secondary tap changer, and a rectifier. The rectifier has ac terminals connected to the secondary tap changer, a first dc terminal connected to the dc link, and a second dc terminal connected to the dc network. The dc terminal voltage of the rectifier is therefore summated with the output voltage of the generator to provide a converter output voltage.

Power converters

In a marine power distribution and propulsion system with a medium voltage distribution busbar (MVAC) and a low voltage distribution busbar (LVAC) then a rectifier (SC) is controlled, optionally to provide active filtering and static compensation benefits. A common power supply system incorporating ac generators (G-G) supplies power to the medium and low voltage distribution busbars. The rectifier (SC) is connected to the medium voltage distribution busbar (MVAC). A controller (Co) uses feedback signals indicative of electrical quantities of the distribution voltages carried by both the medium voltage and low voltage distribution busbars (MVAC, LVAC) to control the rectifier (SC) to regulate electrical quantities at the ac terminals of the rectifier (SC) in order to achieve desired electrical quantities of the distribution voltage carried by the low voltage distribution busbar (LVAC).

Control device for a power distribution system

A semiconductor device or power electronic device is described. The device includes a pair of pole pieces, each having a profiled surface. A semiconductor body or wafer, preferably of wide bandgap electronic material, is located between the pole pieces and includes contact metallization regions. The semiconductor body produces an electric field that emerges from an edge region. Passivation means includes a first or radially inner part in contact with the edge region of the semiconductor body and which diffuses the electric field as it emerges from the edge region and a second or radially outer part. The second part of the passivation is in contact with the first part and provides a substantially void-free interface with the profiled surface of each pole piece. The device may be immersed in a dielectric liquid.

Power electronic devices

A dc electrical machine with a large number of phases. The machine includes a rotor and a stator assembly. The rotor has Np rotating field poles. The stator has Ns winding slots, where Ns/Np is a non-integer ratio. A stator winding includes a plurality of coils received in the winding slots and defines a plurality of stator phases. A power electronic switching assembly includes first and second dc load terminals that can be connected to external equipment and a plurality of switching modules. Each switching module includes power electronic devices and is connected to a respective stator coil. A first proportion of the switching modules are connected together in series between the first and second dc load terminals and a second proportion of the switching modules are connected together in series between the first and second dc load terminals to define two parallel dc circuits.

Dc electrical machines

A circuit breaker comprising a first dc line electrically connectable to first incoming and first outgoing dc lines, wherein the first dc line comprises a first fault-interrupting switch contact system and a first switching aid network. The first switching aid network comprises first and second rectifier strings, wherein each rectifier string comprises one or more series connected reverse blocking power electronic devices that define a first H-bridge rectifier. The first switching aid network further comprises a snubber string, the snubber string comprising at least one series connected power electronic devices capable of being turned on by gate control and a capacitor. The first switching aid network further comprises a pre-charge string comprising at least one series connected power electronic devices capable of being turned on by gate control and a resistor, and a surge arrester connected between the first and second dc output terminals of the first H-bridge rectifier.

Circuit breakers

A converter, and in particular a current source converter, including a bridge having an AC terminal for each of one or more AC lines, and first and second DC terminals. A converter arm is connected between each respective AC terminal and the first DC terminal, and between each respective AC terminal and the second DC terminal. Each converter arm includes a first power semiconductor switching device capable of being turned 'on' and 'off' by gate control and having a recovery time. The converter is adapted to be operated in one or more inverting modes.

Converters

The present invention relates to a vacuum switch assembly for interrupting and isolating fault current. The vacuum switch assembly includes first and second dc lines that, in use, are electrically connected to the dc output terminals of a primary dc power source and a dc network. Each dc line includes at least one vacuum switch having contacts that are opened and closed under the control of a vacuum switch controller. A passive dc power supply unit is electrically connected to the first and second dc lines and includes a secondary dc power source that provides a substantially ripple-free sensing voltage. The vacuum switch controller is adapted to open the vacuum switch contacts when a fault condition (e.g. a fault current or other fault) or an operator request has been identified and when the current flowing between the vacuum switch contacts is below a chopping current associated with the vacuum switches.

Vacuum switch assemblies

A power transmission and distribution system suitable for subsea electrical loads includes a primary dc transmission cable connected to an onshore AC/DC converter module that connects the onshore end of the cable to an ac supply network. The subsea end of the cable is connected to a primary subsea power distribution unit and includes a DC/DC converter module having a modular topology with a series of interconnected DC/DC converter units. The DC/DC converter module is connected between the cable and a primary dc distribution network. Secondary dc transmission cables and associated circuit breakers connect the primary subsea power distribution unit to secondary subsea power distribution units that are located near the subsea loads. Each secondary subsea power distribution unit includes a DC/DC converter module having a modular topology with a series of interconnected DC/DC converter units. Respective secondary dc distribution networks supply power to one or more subsea loads.

Power transmission and distribution systems

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.

Power distribution systems

The present invention provides an electronic commutator circuit for use with a stator winding of an electrical machine. The stator winding of the electrical machine includes a number of coils linked by the same number of points of common coupling. The electronic commutator circuit comprising the same number of switching stages, each switching stage being connected between a respective one of the points of common coupling and first and second dc terminals. Each switching stage further includes a first reverse blocking semiconductor power device (such as a Reverse Blocking Gate Turn Off Thyristor (RB-GTO) capable of being turned on and off by gate control having its anode connected to the first dc terminal, and a second reverse blocking semiconductor power device (RB-GTO) capable of being turned on and off by gate control having its cathode connected to the second dc terminal.

Electronic commutator circuits

An exciter assembly for supplying a field current to the rotor windings of a superconducting synchronous machine includes a pulse transformer having a stationary primary winding, a secondary winding and a tertiary winding. A switched mode power supply supplies a pulsed voltage to the primary winding of the pulse transformer. The pulsed voltage developed at the secondary winding of the pulse transformer is supplied to the rotor windings through a pair of transfer leads. A controller controls synchronous rectification of the pulsed voltage supplied to the rotor windings based on a signal from the tertiary winding of the pulse transformer.

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Rugby, United Kingdom

Allan David Crane