Abstract: A stator coil assembly includes a cylindrical support tube with first and second pluralities of stator coils disposed radially around the support tube. Each stator coil includes first, second, third, and fourth linear segments, each having first and second planar broad sides. The second and fourth linear segments extend in parallel along a first axis with the first and second broad sides of the second and fourth linear segments lying in a common plane. The first and third linear segments extend in parallel along a second axis perpendicular to the first axis. Transition segments having first and second planar broad sides each join a pair of linear segments. The transition segments of the first and second pluralities of stator coils define curvatures toward and away from the center axis, respectively, such that the first and third linear segments are disposed at a substantially equal radial distance from the center axis.

Abstract: A stator assembly including a plurality of stator coil assemblies and a stator coil support structure constructed of a non-magnetic, thermally-conductive material. The stator coil support structure includes an axial passage for receiving a rotor assembly and a plurality of channels positioned radially about the axial passage. Each channel is configured to receive one or more of the stator coil assemblies.

Abstract: A superconducting motor which operates in a synchronous mode of operation, can also be operated in an induction mode in the event that the superconducting components of the motor lose their superconducting properties (e.g., due to cooling system failure). The superconducting electric motor includes a rotor assembly having at least one superconducting winding which, in operation, generates a flux path within the rotor assembly, and a support member which supports the at least one superconducting winding. The rotor assembly is configured to operate in a synchronous mode of operation at temperatures in which the superconducting winding exhibits superconducting characteristics and in a steady-state induction mode of operation at temperatures in which the superconducting winding exhibits non-superconducting characteristics.

Abstract: A stator assembly including a plurality of stator coil assemblies and a stator coil support structure constructed of a non-magnetic, thermally-conductive material. The stator coil support structure includes an axial passage for receiving a rotor assembly and a plurality of channels positioned radially about the axial passage. Each channel is configured to receive one or more of the stator coil assemblies.

Abstract: A stator assembly including a plurality of stator coil assemblies and a stator coil support structure constructed of a non-magnetic, thermally-conductive material. The stator coil support structure includes an axial passage for receiving a rotor assembly and a plurality of channels positioned radially about the axial passage. Each channel is configured to receive one or more of the stator coil assemblies.

Abstract: A stator assembly includes a plurality of stator coil assemblies and a stator coil support structure constructed of a non-magnetic, thermally-conductive material. The stator coil support structure includes an axial passage for receiving a rotor assembly and a plurality of channels positioned radially about the axial passage. Each channel is configured to receive one or more of the stator coil assemblies.

Abstract: A superconducting coil assembly is of the type mounted to a rotor assembly of an electric rotating machine and, in operation, is maintained at cryogenic temperatures while the portion of the rotor assembly is maintained above cryogenic temperatures. The superconducting coil assembly includes at least one superconducting winding wound about a longitudinal axis of the coil assembly and having an inner radial surface defining a bore extending through the coil assembly. The coil assembly also includes at least one support member extending across the bore and mechanically coupled to the portion of the rotor assembly and to opposing portions of the inner radial surface of the at least one superconducting winding.

Abstract: A stator for use in a rotating machine includes a first conductor; and a second conductor wound, in-hand, over the first conductor and along a longitudinal axis of the stator. The second conductor is electrically isolated from the first conductor along the length of the first and second conductors. The multiple conductor in-hand winding construction allows multiple conductors to be combined to increase the overall current handling capability of the stator while substantially maintaining the “packing factor” (i.e., ratio of current-carrying conductor to overall conductor). The packing factor is substantially maintained because the amount of turn-to-turn insulation winding between typical conductors is very small.

Abstract: A stator support system for supporting a stator coil assembly includes an inner support tube having an outer surface; spaced windings supported on the inner support tube with spaces between adjacent windings defining gaps; support members, each disposed within one of the gaps and having a first and second edge configured to mechanically engage the outer surface of the inner support tube; and a cross support positioned over the spaced winding and extending perpendicular to a longitudinal axis of the stator coil assembly. The cross support having a first edge configured to mechanically engage the second edge of the support members.

Abstract: A stator support system for supporting a stator coil assembly includes a inner support tube having an outer surface; spaced windings supported on the inner support tube with spaces between adjacent windings defining gaps; support members, each disposed within one of the gaps and having a first and second edge configured to mechanically engage the outer surface of the inner support tube; and a cross support positioned over the spaced winding and extending perpendicular to a longitudinal axis of the stator coil assembly. The cross support having a first edge configured to mechanically engage the second edge of the support members.

Abstract: An exciter assembly for supplying power to a superconducting load, such as a superconducting field coil, disposed within a cryogenic region of a rotating machine. The exciter assembly provides an efficient and reliable approach for transferring the electrical power energy across a rotating interface. The exciter assembly includes a transformer having a primary winding and a secondary winding, and a rotatable enclosure including a wall having an intermediate core formed of a high permeability material. The intermediate core is positioned between the primary of a transformer and the secondary of the transformer. In essence, the intermediate core acts as a flux “window” or “shunt” between the primary winding and the secondary winding. One of the primary and secondary windings is generally positioned in a rotational reference frame relative to the other of the primary and secondary windings.

Abstract: An exciter assembly for supplying power to a superconducting load, such as a superconducting field coil, disposed within a cryogenic region of a rotating machine. The exciter assembly provides an efficient and reliable approach for transferring the electrical power energy across a rotating interface. The exciter assembly includes a transformer having a primary winding and a secondary winding, and a rotatable enclosure including a wall having an intermediate core formed of a high permeability material. The intermediate core is positioned between the primary of a transformer and the secondary of the transformer. In essence, the intermediate core acts as a flux “window” or “shunt” between the primary winding and the secondary winding. One of the primary and secondary windings is generally positioned in a rotational reference flame relative to the other of the primary and secondary windings.

Abstract: A high temperature superconducting rotor for a synchronous machine includes a high temperature superconducting field winding, a field winding support concentrically arranged about the high temperature superconducting field winding, and a thermal reserve concentrically arranged about the field winding support. The thermal reserve is thermally coupled to the field winding to maintain a temperature differential between the thermal reserve and the field winding not greater than about 10 K.

Abstract: 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.

Abstract: A stator for use in a rotating machine includes a first conductor; and a second conductor wound, in-hand, over the first conductor and along a longitudinal axis of the stator. The second conductor is electrically isolated from the first conductor along the length of the first and second conductors. The multiple conductor in-hand winding construction allows multiple conductors to be combined to increase the overall current handling capability of the stator while substantially maintaining the “packing factor” (i.e., ratio of current-carrying conductor to overall conductor). The packing factor is substantially maintained because the amount of turn-to-turn insulation winding between typical conductors is very small.

Abstract: A method of maintaining a desired level of sub-transient reactance in a superconducting machine includes specifying a desired level of sub-transient reactance. A stator assembly is produced that includes at least one stator coil assembly having a first predefined length. A rotor assembly is produced that is configured to rotate within the stator assembly. An asynchronous field filtering shield, having a second predefined length that is less than the first predefined length, is positioned between the stator assembly and the rotor assembly. The desired level of sub-transient reactance is achieved by adjusting either the first predefined length or the second predefined length.

Abstract: A superconducting rotating machine includes a direct current field excitation source and an alternating current armature winding mounted on a stationary support member, at least one of which includes a superconducting material, a core member formed of a magnetic permeable material and rotatable around the static support member, and a refrigerator unit which cryogenically cools at least one of the field excitation source and the armature winding. The superconducting rotating machine may have a construction for providing polyphase (e.g., three-phase) power.

Abstract: A superconducting machine of the type having a stator assembly and a rotor assembly that rotates within the stator assembly and is spaced from the stator assembly by a gap is disclosed. This arrangement can be used, for example, to produce a superconducting motor or generator. In one aspect of the invention, the superconducting rotating machine includes at least one HTS superconducting winding assembly which, in operation, generates a magnetic flux linking the stator assembly and rotor assembly, a refrigeration system for cooling the at least one superconducting winding of the rotor assembly and the superconducting rotating machine has a torque density of approximately 75 Nm/Kg or more at 500 RPM or less.

Abstract: A superconducting coil assembly is of the type mounted to a rotor assembly of an electric rotating machine and, in operation, is maintained at cryogenic temperatures while the portion of the rotor assembly is maintained above cryogenic temperatures. The superconducting coil assembly includes at least one superconducting winding wound about a longitudinal axis of the coil assembly and having an inner radial surface defining a bore extending through the coil assembly. The coil assembly also includes at least one support member extending across the bore and mechanically coupled to the portion of the rotor assembly and to opposing portions of the inner radial surface of the at least one superconducting winding.

Abstract: A stator assembly includes a plurality of stator coil assemblies and a stator coil support structure constructed of a non-magnetic, thermally-conductive material. The stator coil support structure includes an axial passage for receiving a rotor assembly and a plurality of channels positioned radially about the axial passage. Each channel is configured to receive one or more of the stator coil assemblies.