Nkt Cables Group A/s

Telefonaktiebolaget Lm Ericsson (publ)

Ulf Johnsen

Lars O Efraimsson

Anders Jonas Gatu

Ivar Lars Sune Hansson

Lars-Olof Efraimsson

Henric Magnusson

Lars Efraimsson

The current invention relates to self-supporting cables that often are aerial mounted between cable fixing points () and where the conductors in the cables act as the bearing elements. In this type of cables, slip-page between the surfaces of different layers in the cable is undesirable. On the other hand, it must be possible to easily bend the cable, even for larger dimensions. Both these requirements are difficult to meet with the solutions from prior art. The present invention overcomes this by introducing an intermediate layer () in the cable () located between and adhered to the surfaces () of the layers and having a frictional inner structure allowing the two surfaces () to slip relatively each other in longitudinal direction enough so that the cable () can be bent but prevents the two surfaces {) from slipping in response to an inwardly directed radial pressure force (F) at the cable fixing points ().

Self-supporting cable

The current invention relates to self-supporting cables that often are aerial mounted between cable fixing points () and where the conductors in the cables act as the bearing elements. In this type of cables, slippage between the surfaces of different layers in the cable is undesirable. On the other hand, it must be possible to easily bend the cable, even for larger dimensions. Both these requirements are difficult to meet with the solutions from prior art. The present invention overcomes this by introducing an intermediate layer () between the surfaces () comprising at least on tape () with friction particles () where the friction obtained by the friction particles () is low enough to allow the two surfaces () to slip relatively each other in longitudinal direction enough so that the cablecan be bent but prevents the two surfaces () from slipping in response to an inwardly directed radial pressure force (F) at the cable fixing points ().

The present invention relates to problems how to keep cable arrangement functional, or at least make the damage as little as possible, after being exposed to different types of mechanical overloads. The problems are solved by methods and arrangements in which the securing means and the contact material of the securing means are arranged so that the cable can slide through the securing means when it is exposed to mechanical overloads.

Cable suspension device

A power cable comprises at least one insulated cable core having an electric conductor, a screen and an outer insulating sheath surrounding the core/cores, and an outer conducting material attached to the exterior of the outer sheath. The outer conducting material includes at least one band attached to the outer sheath extending along the full length of the cable and having a width (W) extending over only a part of an outer periphery of the cable. At least one groove extends along the cable outer sheath and the band/bands of conducting material are received in the groove/grooves, or at least one rib extends along the cable outer sheath and the band/bands of conducting material are attached to an outer surface of said rib/ribs; or at least one band of the outer conducting material is adhered to the outer sheath and requires a stripping force.

Power cable with conducting outer material

The invention relates to distribution of electrical power, supervision and security. The invention comprises a power feeding station PFS for delivering electrical power. The PFS comprises a low voltage side LVS, a high voltage side HVS and a transformer TF which is configured to deliver high voltage single phase alternating current on the high voltage side, The power can be distributed, via a cable, to one or more power receiving stations PRS. The cable is configured to distribute current-symmetrical single phase current delivered by the power feeding station. The cable can preferable be a coaxial cable with the shield as current return path. The invention also comprises a current sensor unit CSU which is situated on the high voltage side. The means for measuring characteristics of the current CD can comprise a coil without galvanic contact with the high voltage side. A circuit break unit CBU suitable for breaking the current is situated on the low voltage side. A control function CF is configured to activate the circuit break unit based on the safety rules and the characteristics of the current CD. Characteristics of the current and other system information SI can also be delivered to an information unit IU.

Power station for power transmission to remotely located load

The figure shows an electrical cable with conductors () of metal, surrounded by each of an inner conducting layer (), insulation () and an outer conducting layer (). A moisture barrier () with an electrically conducting layer surrounds the conductors. Shield strips () of at least partially conducting material are located in the regions between the outer conducting layer () and the moisture barrier (). Electrically conducting shield wires () run along the shield strips and are placed through these into electrical contact with the electrically conducting layer of the moisture barrier (). The shield strips support the moisture barrier from the inside, such that the moisture barrier can in a simple manner be made watertight when it is applied. The shield strips (), the moisture barrier () and the shield wires () together constitute an efficient electrical shield for the cable. Penetration of an electrically conducting object into the cable results in a fault current that can be easily indicated, such that an applied cable voltage can be removed.

Cable with shielding strip

Self-supporting cables include at least one insulated conductor that includes a conductor having at least one wire and an insulation around the cable conductor. The cable further includes at least one longitudinally extending shield band and a jacket. The shield band is rigid in a radial direction and includes undulations that extend mainly in a tangential direction. The shield band includes undulations which correspond to the jacket undulations. A weak radially acting compressive force causes the jacket undulations and the shield band undulations to cam into each other, such that the force of gravity acting on the cable between the cable fixing points is transmitted into the conductors, and an axially acting force in the absence of slippage between the different cable layers. The cable becomes self-supporting by virtue of the mechanical strength of the conductors.

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Falun, Sweden

Ulf Johnsen