Abstract: In certain embodiments, an assembly has intermediate pods magnetically, but not galvanically, coupled along an electrically conductive cable. Each pod has a magnetic core surrounding and inductively coupled to the cable and one or more coils inductively coupled to the magnetic core. The pod transmits, for example, outgoing current pulses on the cable by inducing electrical signals in the cable using a transmitter coil and the magnetic core. In addition, the pod repeats, for example, incoming current pulses on the cable by inducing electrical signals in the cable using the transmitter coil and the magnetic core, based on electrical signals induced in a receiver coil via the magnetic core by the incoming current pulses. Such an assembly can function as a data collection system for scientific research and/or as an early-warning system for events, such as earthquakes and tsunamis, without having to modify the cable itself.

Abstract: A branching unit integrated into a submarine telecommunication system comprising three cables having optical and electrical transmission members comprises three terminals connected to the electrical transmission members of the cables, three input points, and three electrical contacts each between one of the terminals and one of the input points. In an operating configuration, and at a given time, a first terminal and a second terminal are electrically connected together and form a trunk segment adapted to convey a trunk current, and a third terminal is electrically connected to a submarine ground to form a branch segment adapted to convey a branch current. The branching unit carries out reconfiguration by controlling switching of the electrical contacts. A voltage indicating the potential at a point on the trunk segment is measured. Because an optical reconfiguration request is made by means of an optical reconfiguration signal the unit is able to receive and process optical reconfiguration signals.

Abstract: A branching unit integrated into a submarine telecommunication system comprising three cables having optical and electrical transmission members comprises three terminals connected to the electrical transmission members of the cables, three input points, and three electrical contacts each between one of the terminals and one of the input points. In an operating configuration, and at a given time, a first terminal and a second terminal are electrically connected together and form a trunk segment adapted to convey a trunk current, and a third terminal is electrically connected to a submarine ground to form a branch segment adapted to convey a branch current. The branching unit carries out reconfiguration by controlling switching of the electrical contacts. A voltage indicating the potential at a point on the trunk segment is measured. Because an optical reconfiguration request is made by means of an optical reconfiguration signal the unit is able to receive and process optical reconfiguration signals.

Abstract: Method of maintaining a superconducting cryolink at low temperature by a flow of liquid nitrogen produced by a liquefier feeding one end of a link section, wherein the section is fed by a single liquefier and nitrogen is drawn off from at least one intermediate point of the link section.

Abstract: An electric transformer comprising a primary coil and a secondary coil each constituted by at least a first coil formed by winding one or more metal-matrix superconductive conductors. The first coil of the primary coil or of the secondary coil is connected in series with at least one second coil formed by a solid superconductive tube machined to form a solenoid, the second coil being disposed coaxially with the first coil. This design contributes to protecting the transformer by means of its current-limiting effect.

Abstract: An electrical transmission line for conveying and limiting current by using a plurality of tubular portions made from a superconductive material. The tubular portions have a high critical temperature and are connected end-to-end by flexible, electrically conductive metal or alloy joints. A cryogenic fluid flows inside a first tube within the tubular portions. A vacuum is maintained inside a second tube around the tubular portions.

Abstract: A superconductive conductor protected against partial transitions, the conductor comprising a superconductive region made up of superconductive filaments embedded in a non-superconductive metal matrix, and a non-superconductive metal region, wherein the cold resistivity of the non-superconductive metal region is less than half the overall cold resistivity of the superconductive region in the non-superconductive state, the superconductive region and the non-superconductive metal region being merely in mechanical contact, without cohesion.

Abstract: A superconducting switch comprising a portion of cable including a resistive central strand that is non-superconducting having a plurality of super-conducting strands or of superconductors twisted thereabout, and separated from the central strand by electrical insulation, the cable as a whole being insulated from the external cooling medium by thermal insulation. The central strand is electrically connected to the superconducting strands or the superconductors at each end of a portion of cable. A portion of the length of the resistive central strand extends outside the cable at a point along the length of the portion of said cable and is coupled to a control device situated outside the cooling medium, wherein the control device injector an electrical current into the circuit formed by the resistive central strand that is connected at its ends to the superconducting strands or to the superconductors.

Abstract: A superconducting current limiter comprising a bar or tube of high temperature superconducting material of the composite type made up of glass and a high temperature superconducting oxide, the volume fraction of the glass lying in the range 10% to 40%, the bar or tube being selected to comply with the following inequalities:.rho.>10.sup.-4 .OMEGA..multidot.mj.sub.c >10.sup.+5 A/m.sup.2.rho.x.sup.2 <10.sup.11 W/m.sup.3in which inequalities:.rho. designates the resistivity of the material in the normal, i.e. the non-superconducting, state;j.sub.c designates the critical current density;.rho.x.sup.2 designates the power density dissipated in the bar or tube during the transition stage;it being specified that the critical current density is defined as the density which produces an electric field of 10.sup.-4 V/m along the tube or bar and that it is accepted that limitation takes place for a current density equal to five times the critical current density.

Abstract: The present invention relates to a superconductive coil assembly which may be used particularly for a current limiter, the coil assembly comprising a plurality of coaxial cylindrical coils electrically connected in series, each coil comprising two windings of superconductive material electrically connected in parallel, arranged coaxially and wound in opposite directions, wherein in each coil, the windings are separated by a material which has a surface resistance in the radial direction lying in the range 10.sup.-5 .OMEGA..m.sup.2 to 10.sup.-2 .OMEGA..m.sup.2 at the temperature of the cryostat, and in which the strands which constitute the superconductive wires may themselves be covered with a layer of the same material.

Abstract: A superconductor protected against partial transition includes superconductor strands around at least one non-superconductor central strand or at least one non-superconductor central core electrically insulated from the superconductor strands. At least at both ends of the superconductor, the central strand or said central core is electrically connected to the superconductor strand. The central strand or the central core comprises at least one non-superconductor metal filament whose resistivity at 4.2.degree. K. is less than 10.sup.-9 .OMEGA..m embedded in a metal alloy matrix whose resistivity at that temperature is greater than 10.sup.-8 .OMEGA..m.

Abstract: The invention relates to a circuit breaker for limiting a direct current and comprising a combination of first means including superconducting windings for limiting the current and second means for interrupting the residual current. The invention is applicable to interrupting high tension direct currents.

Abstract: A multifilament superconducting strand for use at industrial frequencies and made from an initial billet comprising a superconducting core niobium-titanium alloy surrounded by an anti-diffusion barrier layer which is in turn surrounded by a copper based matrix material, with the strand being made from the billet by successive stages of extrusion, wire-drawing, and assembly, wherein the strand includes 5.times.10.sup.5 to 5.times.10.sup.6 filaments each constituted by the superconducting core reduced to a diameter in the range 50 nm to 150 nm, the filaments being separated from one another by a distance lying in the range 30 nm to 100 nm, which distance is occupied by the anti-diffusion layer and the matrix material. The matrix material contains in excess of 8% manganese when the anti-diffusion layer is made of niobium, or alternatively, the anti-diffusion layer may be of an iron-containing alloy with the matrix containing copper and nickel.