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Abb Technology Ag

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Abb Research Ltd.

Asea Brown Boveri Ab

Abb Technology Ltd

Hitachi Energy Switzerland Ag

Lars Liljestrand

Stefan Valdemarsson

Elisabeth Lindell

Lars E Jonsson

Per Skarby

Felix Greuter

Jesper Magnusson

Birger Drugge

Nils-Johan Bergsjo

Jens Tepper

Andrea Bianco

Stefan G Thorburn

Frans Dijkhuizen

Stefan Halén

Robert Saers

Per Halvarsson

Carlo Gemme

Richard Tinggren

Martin Carlen

Lennart Ängquist

Magnus Backman

Andrea Ricci

Henrik Breder

Tomas Tengner

Jan Isberg

Erik Forsberg

Hans Bernhoff

Jakub Korbel

Emmanouil Panousis

Jadran Kostovic

Thorsten Steinmetz

Markus Bujotzek

Bernhard Doser

Per Lindholm

Philip Carne Kjaer

Ake Petersson

Urban Åström

Emile Schreurs

Daniel Ohlsson

Victor Lescale

Ambra Sannino

Claes Bengtsson

Dierk Bormann

Peter Dubach

Ryan Chladny

Åke Petersson

Philipp Buttgenbach

Willie Wong

Karl-Heinz Hartung

S&ouml;ren Petersson

Ueli Steiger

Urban Astroem

Peter Jones

Tobias Hintzen

Philipp Buttenbach

The present invention relates to a method for controlling a motor-driven vacuum circuit breaker. The method comprises initiate opening (S) the circuit breaker, wherein the circuit breaker moves with an average opening speed of a contact pair of the circuit breaker, from a closed position to an open position of the circuit breaker, and decelerating (S) the opening speed of the contact pair to below the average opening speed before the open position is reached to avoid overshoot, and initiate closing (S) the circuit breaker, wherein the circuit breaker moves with an average closing speed of the contact pair, from the open position to the closed position, and decelerating (S) the closing speed of the contact pair to below the average closing speed before contact touch at the closed position, wherein the circuit breaker moves with the decelerated speed at contact touch. A motor-driven vacuum circuit breaker, a computer program and a computer program product are also presented.

Motor-driven vacuum circuit breaker

A method for controlling a circuit breaker, the circuit breaker is connected in a three-phase system having an inductive load, and the method includes a method for controlling a circuit breaker, the circuit breaker being connected in a three-phase system having an inductive load, the method includes opening a first phase of the three-phase system before a zero crossing of a current in the first phase, opening the second and third phases of the three-phase system a quarter period after opening the first phase, closing the first and second phase at a peak voltage of a voltage between the first and second phases, and closing the third phase a quarter period after closing the first and second phases. A circuit breaker controller is also presented.

Three-phase circuit breaker with phase specific switching

An electric power distribution switchgear is connected between an electric power grid and an electric power equipment. The switchgear includes a synchronized vacuum switching apparatus configured to break the current to the electric power equipment using a synchronized technique to avoid re-ignition during the breaking and thus any transients caused by such re-ignition; and a surge arrester arrangement connected to the electric power equipment, the surge arrester arrangement being designed and configured to only handle transients caused by the current chopping at the breaking. The surge arrester arrangement can be arranged remote from the electric power equipment, such as e.g. in the same casing as the synchronized vacuum switching apparatus.

Electric power distribution switchgear and method of breaking an electric power current

A passive electronic fuse for protecting a DC application in the event of a fault includes a first leg including a first winding of a mutual inductor and a switch device connected in series, a second leg including a second winding of the mutual inductor. The first leg and the second leg are connected in parallel and a self-inductance of the second winding is lower than a self-inductance of the first winding. The second leg further includes a capacitor connected in series with the second winding of the mutual inductor, and the switch device is a thyristor or a switch device with switching properties of a thyristor.

Passive electronic fuse for protecting a DC application

A transformer arrangement and transformer for mitigating transient voltage oscillations. The transformer included a transformer core enclosing at least one core leg. A winding is wound around one of the at least one core leg. The winding extends from a first winding terminal to a second winding terminal and includes a first winding section along a first conductor extending from the first winding terminal to a first intermediate end point, and a second winding section along a second conductor extending from a second intermediate end point to the second winding terminal. The transformer arrangement further includes an external passive electric component connected between the first intermediate end point and either the second intermediate end point or the second winding terminal arranged to decrease an effective difference between capacitive and inductive voltage distributions between the intermediate end points such that transient voltage oscillations in the winding are mitigated.

Transformer arrangement for mitigating transient voltage oscillations

A system for transient over voltage protection of a three-phase transformer. Two surge arresters are series connected across each winding of the transformer and the center point connection of the two surge arresters is electrically connected to a middle location of the winding. Three additional surge arresters are electrically connected from each phase to ground in the case of either a delta or Y connected transformer; and/or connected from a neutral point to ground in the case of a Y connected transformer. The system allows for all of the surge arresters to be packaged as an integrated surge arrester system to minimize induced transient over voltages and high stresses on the transformer winding due to internal resonances.

System for protection of dry type transformers

A multi-terminal surge arrester which includes an active part extending along a longitudinal direction of the surge arrester, a first electrode resting against a first end of the active part, and a second electrode resting against a second end of the active part, which second end opposes the first end in the longitudinal direction of the surge arrester. The surge arrester further includes an insulating fixing device mechanically connecting and fixing the first electrode and the second electrode, and an insulating housing arranged around the active part. The active part includes at least two metal-oxide based varistor elements and a further electrode arranged between the at least two varistor elements, which further electrode provides an externally accessible electrical connection. Therein, the surge arrester is adapted for being insulated by surrounding air.

Multi-terminal surge arrester

An apparatus is arranged to break an electrical current. The apparatus includes: a mechanical switch leg including a first winding of a mutual inductor and a mechanical switch connected in series; a semiconductor switch leg including a second winding of the mutual inductor and a semiconductor switch connected in series; and an overvoltage protection circuit. The mechanical switch leg and the semiconductor switch leg are connected in parallel and a self inductance of the second winding is lower than a self inductance of the first winding. A corresponding DC circuit breaker and AC current limiter are also presented.

Apparatus arranged to break an electrical current

An exemplary medium or high voltage switch has a first set of contact elements and a second set of contact elements. Each contact element includes an insulating carrier carrying conducting elements. In the closed state of the switch, the conducting elements align to form one or more current paths between terminals of the switch along an axial direction. For opening the switch, the contact elements are mutually displaced by means of one or two drives along a direction perpendicular to the axial direction. The switching arrangement is arranged in a fluid-tight housing in a gas of elevated pressure or in a liquid. The switch has a high voltage withstand capability and fast switching times.

Switch having two sets of contact elements

A DC current path for DC power transmission includes at least a first switching element and a second switching element connected in series. A resonance circuit is configured to be connectable in parallel to the series connection of the at least one first switching element and second switching element by means of a switch.

Circuit arrangement and method for interrupting a current flow in a DC current path

An exemplary medium or high voltage switch has a first set of contact elements and a second set of contact elements. Each contact element includes an insulating carrier carrying conducting elements. In the closed current-carrying state of the switch, the conducting elements align to form one or more current paths between terminals of the switch along an axial direction. For opening the switch, the contact elements are mutually displaced by through two drives along a direction perpendicular to the axial direction. The switching arrangement is arranged in a fluid-tight housing in a gas of elevated pressure or in a liquid. The switch has a high voltage withstand capability and fast switching times.

Switch having two sets of contact elements and two drives

An arrangement to control an electrical property of a medium or high voltage AC system including a number n of phases with n being at least two includes a number n of phases, each phase including a series connection of at least two electrical elements with an intermediate connection point between each pair of the at least two electrical elements, where each of the n phases of the arrangement is connected on one side to an original common neutral point and on the other side to one of the n phases of the AC system. The arrangement further includes a number of first switchable interconnections, where the first switchable interconnections are each arranged between two intermediate connection points of two of the n phases of the arrangement, and at least one control unit arranged to control the first switchable interconnections.

Method and arrangement to control an AC system

An apparatus for reactive power compensation in an ac medium voltage power network. The apparatus includes a common connection; a first branch including a first switch, and a first capacitor; and a second branch including a second switch and a second capacitor.

Electric power flow control

A rotating electric motor for operating an electric component. The motor is arranged for an operating movement during a limited predetermined angular motion of the rotor of the motor. An electric drive circuit is arranged for the winding of the motor. The electric circuit exhibits at least one branch including an electric energy bank and a thyristor, which are connected in series with the motor winding. Also, a method for breaking, a use of the motor, and an electric switch provided with the motor.

Rotating electric motor for operating an electric component

An electric network for generation and transmission of electric power, including a power generating part, a point of common connection for the power generating part, a transmission link, a load network, and a reactive power compensator. The transmission link is coupled between the point of common connection and a grid connection point at the load network. The reactive power compensator is coupled to transmission link. The power generating part includes at least one wind turbine with an electric generator of induction type, coupled to the point of common connection. The reactive power compensator includes a capacitor bank and in parallel coupling to the capacitor bank a controllable inductor having a magnetic core, a main winding for alternating current, and a DC-control winding for direct current. The DC-control winding for control of the magnetic flux is set up by the main winding via orthogonal magnetization of the core.

Wind power fed network

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Västerås, Sweden

Lars Liljestrand