Abb Ab

Abb Research Ltd.

Asea Brown Boveri Ag

Asea Brown Boveri Ab

Li Ming

Mats Leijon

Udo Fromm

Par Holmberg

Dan Windmar

Gunnar Kylander

Sven Hornfeldt

Bertil Berggren

Gunnar Russberg

Christian Sasse

Hans Bernhoff

Mikael Dahlgren

Jan Isberg

Pan Min

Bertil Moritz

Rongsheng Liu

Liu Rongsheng

Mikael Bergkvist

Anders Sunesson

Mats Ekberg

Svante Söderholm

A power transformer/inductor includes at least one winding. The winding is made of a high voltage cable that includes an electric conductor, and around the electric conductor is arranged a first semiconducting layer, around the first semiconducting layer is an insulating layer, and around the insulating layer is a second semiconducting layer. The second semiconducting layer is directly earthed at both ends of the winding and furthermore at least at two points per turn of every winding such that one or more points are indirectly earthed.

Power transformer/inductor

The present invention relates to a power transformer/inductor comprising at least one winding. The windings are designed by means of a high-voltage cable, comprising an electric conductor, and around the conductor there is arranged a first semiconducting layer, around the first semiconducting layer there is arranged an insulating layer and around the insulating layer there is arranged a second semiconducting layer. The second semiconducting layer is earthed at or in the vicinity of both ends () of each winding and furthermore one point between both ends () is directly earthed.

A distributed air gap material for a induction device in power systems for minimizing fringe losses, mechanical losses and noise in the core The distributed air gap material occupies a selected portion of the core and is formed of a finely divided magnetic material in a matrix of a dielectric material particles. The air gap material has a zone of transition in which the permeability values vary within the air gap material.

Induction devices with distributed air gaps

An electrode for control of an electric field strength in a gaseous electrically insulating medium at the surface of the electrode and in the vicinity of the electrode, comprising an electrically conducting inner electrode ( &prime;) and an electrically non-conducting layer ( ) on at least parts of the surface of the inner electrode, wherein the thickness of the non-conducting layer is at least 5% of the mean diameter of the inner electrode and that the relative dielectric constant of the non-conducting layer is smaller than 3.

Electrode for field control

This invention is related to a device and a method in an electric power plant for protection of an object (,) against over-currents from a network (,) or another equipment included in the high voltage plant, the device comprising a switching device (,) in a line (,) between the object and the network/equipment. The line (,) between the object and the network/equipment is connected to an arrangement (,) reducing over-currents towards the object (,), said arrangement (,) being actuatable for over-current reduction with the assistance of an over-current condition detecting arrangement (,) within a time period substantially less than the break-time of the switching device (,).

Device and method relating to protection of an object against over-currents comprising over-current reduction

The line section of a gas-insulated line contains a high-voltage electric conductor and a pressure pipe which is made from a thermoplastic material and filled with insulating gas. The pressure pipe holds the electric conductor on insulated supports. The pressure pipe has two pipes which are welded to one another on the end faces thereof, the end section being respectively widened to flare outwardly in the radial direction with the welding of the two pipes.

Line section of a gas-insulated line

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Vasteras, Sweden

Li Ming