Abstract: A hybrid current limiter comprising a first winding of non-superconducting conductive material having a large number of turns and electrically connected in series with a superconductoring coil of low self-inductance and placed in a cryostat, and a second winding of non-superconducting conductive material having a small number of turns, said second winding being closely coupled with said first winding in such a manner as to obtain low overall inductance, the second winding being connected in parallel with the series circuit constituted by the first winding and the superconducting coil.

Abstract: A detection device for detecting transitions to the normal state in a superconducting winding, in particular in an electricity generator, and a protection device for protecting such a winding.A detection device for detecting transitions in conductors from the superconducting state to the superconducting state in a superconducting winding at industrial frequency, in particular for the stator of an electricity generator (1). The device comprises an auxiliary generator (4) for generating a low current at a frequency which is considerably higher than industrial frequency, said current being single-phase or multi-phase depending on whether the main current through the winding is single-phase or multi-phase, said auxiliary generator being connected in parallel with the superconductor winding, the device further including means (5, 6) for detecting the change in phase difference between the auxiliary current and the auxiliary voltage which occurs when the conductors of said winding switch to the normal state.

Abstract: The electric rotating machine has a stator and a rotor with superconducting windings placed within separate cryogenic enclosures for the stator and the rotor. The cryogenic enclosures are in turn placed within evacuated thermal insulation enclosures separated by the annular clearance space which is at low pressure, thus considerably simplifying the arrangements required for dynamic sealing of motor bearings.

Abstract: An electric machine stator (6) having superconducting three-phase windings, the stator comprising tubular elements (7, 8) and end plates (9, 10) forming a cryogenic enclosure containing a bath of liquid helium at very low temperature, with the windings being disposed in said bath, an additional tubular element (11) supporting said enclosure at one of its ends and fixed at its other end in sealed manner to an additional end plate (3), annular screens (13, 14) for reflecting radial thermal radiation, and current leads to the windings, the stator including the improvements whereby the tubular elements and the end plates forming the enclosure, the tubular element supporting the enclosure, and the annular screens for reflecting radial thermal radiation are based on a material which does not conduct electricity, and whereby the annular screens for reflecting radial thermal radiation are covered with layers (41, 43) of metal wires of high thermal conductivity, each of which layers has at least one point thereof put