Abstract: There is provided an electrical switch comprising a length of superconducting material. In some forms the electrical switch is configured to be controlled between a low-resistance state and a higher-resistance state by the selective application of one or more switching mechanisms. In the higher-resistance state, current flowing through the length of superconducting material may approach the critical current of the length of superconducting material, may be substantially equal to the critical current or may be greater than the critical current. In some forms, the length of superconducting material is a length of high temperature superconducting material.

Abstract: The invention relates to a superconducting electrical switch. The switch comprises two parallel branches of superconducting material in a loop, and a magnetic field generator which generates a time-varying magnetic field through the loop in a direction generally parallel to the axis of the loop. The magnetic field generator is selectively activated and de-activated to switch the electrical switch between a low-resistance state and a higher-resistance state. In the low-resistance state, there is no magnetic field through the loop and transport current flows through the loop. In the higher-resistance state, a magnetic field through the loop induces a screening current such that the sum of the transport current and the screening current is substantially equal to the critical current or is greater than the critical current of the superconducting material. The switch may be used in, for example, a rectifier or fault current limiter.

Abstract: An optical fibre sensing system (300) with an incident light source (309), a wavelength spectrum interrogator (313), and an optical fibre (302) with a substantially continuous fibre Bragg grating (306). An upstream portion (318) of the optical fibre has an attenuation length to light to the interrogator (313) at a first equilibrium wavelength. A downstream portion (322) of the optical fibre reflects light to the interrogator (313) when a change in temperature and/or strain at the downstream portion (322) causes a portion of the fibre Bragg grating to reflect light to the interrogator (313) at a second wavelength and at a second intensity. A processor (315) is configured to analyse the reflected spectrum (314) to determine when a portion of the fibre Bragg grating (306) is experiencing a change in temperature and/or strain based on deviation in the reflected spectrum (314) from an initial peak corresponding to the initial wavelength.

Abstract: A superconducting current pump arranged to cause a DC electrical current to flow through a superconducting circuit accommodated within a cryogenic enclosure of a cryostat comprises a rotor external to the cryogenic enclosure and a stator within the cryogenic enclosure, the rotor and stator separated by a gap through which passes a thermally insulating wall of the cryogenic enclosure, the rotor and the stator comprising at least in part a ferromagnetic material to concentrate magnetic flux in a magnetic circuit across the gap between the rotor and the stator and through the wall, so that movement of the rotor external to the cryogenic enclosure relative to the stator within the cryogenic enclosure induces a DC transport current to flow around the superconducting circuit within the cryogenic enclosure.

Abstract: A cable winding machine for winding transposed cable from multiple serpentine subconductors such as in particular Roebel cable from such 2G HTS tape, without damaging the tape through edge-wise bending, comprises a conductor supply stage carrying subconductor supply spools to move the supply spools about a machine axis and maintain the supply spools in a common orientation as the subconductors unwind and move through the machine in a machine direction, and a cable forming stage after the conductor supply stage in the machine direction, arranged to bring together the subconductors and at which the subconductors interleave to form the transposed cable.

Abstract: A superconducting current pump arranged to cause a DC electrical current to flow through a superconducting circuit accommodated within a cryogenic enclosure of a cryostat comprises a rotor external to the cryogenic enclosure and a stator within the cryogenic enclosure, the rotor and stator separated by a gap through which passes a thermally insulating wall of the cryogenic enclosure, the rotor and the stator comprising at least in part a ferromagnetic material to concentrate magnetic flux in a magnetic circuit across the gap between the rotor and the stator and through the wall, so that movement of the rotor external to the cryogenic enclosure relative to the stator within the cryogenic enclosure induces a DC transport current to flow around the superconducting circuit within the cryogenic enclosure.

Abstract: A cable winding machine for winding transposed cable from multiple serpentine subconductors such as in particular Roebel cable from such 2G HTS tape, without damaging the tape through edge-wise bending, comprises a conductor supply stage carrying subconductor supply spools to move the supply spools about a machine axis and maintain the supply spools in a common orientation as the subconductors unwind and move through the machine in a machine direction, and a cable forming stage after the conductor supply stage in the machine direction, arranged to bring together the subconductors and at which the subconductors interleave to form the transposed cable.

Abstract: A cable winding machine for winding together a multiple number of subconductors into a composite cable includes holding means for holding a first subconductor in the machine direction, and in a predetermined orientation of the first subconductor about its longitudinal axis as it moves through the machine; a first rotating member arranged and rotate the second subconductor around the first subconductor as the second subconductor moves through the machine and one or more further rotating members arranged to hold further subconductors aligned in the machine direction and in a predetermined orientation about their longitudinal axes and rotate the further subconductors around the subconductors wound with one another in the first winding stage of the machine.

Abstract: A cable winding machine for winding together a multiple number of subconductors into a composite cable includes holding means for holding a first subconductor in the machine direction, and in a predetermined orientation of the first subconductor about its longitudinal axis as it moves through the machine; a first rotating member arranged and rotate the second subconductor around the first subconductor as the second subconductor moves through the machine and one or more further rotating members arranged to hold further subconductors aligned in the machine direction and in a predetermined orientation about their longitudinal axes and rotate the further subconductors around the subconductors wound with one another in the first winding stage of the machine.

Abstract: A cable winding machine for winding together a multiple number of subconductors into a composite cable includes holding means for holding a first subconductor in the machine direction, and in a predetermined orientation of the first subconductor about its longitudinal axis as it moves through the machine; a first rotating member arranged and rotate the second subconductor around the first subconductor as the second subconductor moves through the machine and one or more further rotating members arranged to hold further subconductors aligned in the machine direction and in a predetermined orientation about their longitudinal axes and rotate the further subconductors around the subconductors wound with one another in the first winding stage of the machine.