摘要:
An elongated current limiting composite material comprising one or more high-temperature superconductor filaments and a second electrically conductive member, which may include a sheath of high bulk resistivity surrounding the filament. The current limiter exhibits dissipation in the range of 0.05-0.5 V/cm at currents of 3-10 times the operating current, thereby minimizing fault currents and improving recovery capability.
摘要翻译:包括一个或多个高温超导体细丝和第二导电构件的细长限流复合材料,其可以包括围绕细丝的高体积电阻率的护套。 电流限制器在工作电流的3-10倍的电流下表现出0.05-0.5 V / cm的范围内的耗散,从而最大限度地减少故障电流并提高恢复能力。
摘要:
In a current limiting arrangement based on a superconducting transformer (30), a load (21) can be supplied with power without any interruption by providing an auxiliary winding (14) in parallel with the superconducting primary winding (12) of the transformer (30). This auxiliary winding (14) carries the excess current in the event of a short circuit and allows the superconducting primary winding (12), which has been heated due to the current limiting, to cool down. Once the short circuit has been cleared, the latter winding can once again carry the rated current, without any losses, immediately. The auxiliary winding (14) is composed of a normally conductive material and has an additional stray impedance.
摘要:
A superconducting conductor and its method of manufacture includes an electrical conductor having a thermal conductor attached to and along a length of superconductor member and separated from the superconductor member by an electrically-insulative material. The member may include a length of superconductor composite having superconducting material and a non-superconducting, electrically conductive matrix material. The electrical conductor is configured to control the manner in which the superconductor transitions from its superconducting state to its non-superconducting (i.e., normal) state due to, for example, a fault current condition. The electrically-insulative material has a thickness for allowing heat from the superconductor to be conveyed to the thermal conductor. The superconducting conductor may be used in conjunction with a superconducting current-limiting device.
摘要:
In a superconducting current limiter 1, in the limiting state pressure waves which may damage the superconductor are produced as a result of the evaporation of cooling liquid. According to the invention, the current limiter is not immersed in a cooling liquid, but rather is brought into thermal contact with a cooling fluid 22 which does not undergo a phase transition at over the operating temperature and therefore does not evaporate in the limiting state. A refrigeration reservoir 21, which may be the condensed phase of a gaseous cooling fluid or a cryogenic cooler, determines the operating temperature of the current limiter. One advantage is that it is now possible for a plurality of plate-like current-limiter modules 10, 10′ of unlimited size to be arranged next to one another in the cooling fluid 22.
摘要:
In the case of high-temperature superconductors (6) which are used as inductive current limiters, unless any special precautionary measure is taken, there is a risk that short-circuit currents can lead to local stress centers and hot spots, and to local destruction of the high-temperature superconductor. In order to avoid this, a hollow cylinder (SL) of the high-temperature superconductor (6) is coated with a 1 .mu.m thick conductive-silver layer (E1). A second 10 .mu.m thick metal layer of foil made of silver or aluminum can be deposited thereon. In order to reduce or to avoid tensile stresses in the ceramic of the hollow cylinder (SL) made of a high-temperature superconductor, and in order to reduce the electrical contact resistance of the metal layers, this hollow cylinder (SL) has a mechanical reinforcing element (7), made of an elastic steel wire, wound around it, at room temperature, under tensile stress. Subsequently, this reinforcing element (7) is fixed by means of a solder or a cold-resistant synthetic resin (8), so that reinforcing element tensile stress and a compressive pressure on the hollow cylinder (SL) are maintained even at temperatures below 100K.
摘要:
An electrically stabilized thin-film high-temperature superconductor includes a superconductive layer (32) applied over a flat metallic substrate (31) and connected to the metallic substrate (31) so that electrical contact between the superconductive layer (32) and the metallic substrate (31) is distributed over the area of the metallic substrate (31).
摘要:
Ceramic high-temperature superconductors (1) which are intended to be used as current limiters in alternating-current lines should have a bypass layer (2) whose electrical resistivity is increased by more than 10 times with respect to that of a pure noble-metal bypass layer. In order to achieve this, the noble-metal bypass layer (2) of the high-temperature superconductor (1), preferably of silver, is alloyed with a base metal, preferably Pb or Bi or Ga, by a thermal treatment. The ratio of the bypass layer thickness (d2) of the noble-metal bypass layer (2) to the superconductor layer thickness (d1) is adjusted to 0.5×&rgr;3/d3, where &rgr;2 and &rgr;3 are the electrical resistivity of the noble-metal-containing bypass layer (2) and the base-metal bypass layer (3, 3′), respectively.
摘要:
The present invention relates to a resistive superconducting current limiter with a meandering shape. This current limiter avoids current density peaks at the turning points (12) or corners of the conductor track (10, 11) in that the central path of the fault current when limiting occurs is artificially increased by appropriate design of the turning points. For this purpose, conductor material is removed in the region of the inner edge of the turning points (13), or the electrical bypass is reinforced at its outer edge (14).
摘要:
The invention is concerned with a resistive fault current limiter (FCL) based on thin superconducting films. The FCL comprises constrictions (2) with a reduced critical current, separated by connecting paths (3). Upon occurrence of a fault current, the former turn resistive simultaneously and build up a resistance which allows the applied voltage to drop entirely only over the constrictions. Only at a later stage, the connecting paths become resistive and dissipate energy. The thickness and width of an electrical bypass determine said normal resistivities of the constrictions and the connecting paths.
摘要:
An apparatus in the field of power transmission, the apparatus includes a superconducting component or another component to be cooled, in a cryostat. A vacuum switch is provided in order to prevent heat being introduced into the cryostat by means of thermal conduction through the electricity cable of the component in the event of an electricity failure. This vacuum switch is integrated in a bushing in the electricity cable, so that its vacuum completes the thermal insulation of the cryostat.