Abstract: A superconducting fault current limiter (10) is shown. It comprises a cryostatic cooling system (20) for containing a cooling medium (26), a superconducting wire (30) immersed in the cooling medium (26) and configured to carry a current, the superconducting wire (30) becoming non-superconducting above a critical current density, and a plurality of heat dissipation elements spaced along and projecting from the superconducting wire (30), wherein the heat dissipation elements have an electrically insulating coating, and whereby the heat dissipation elements transfer heat from the superconducting wire (30) into the cooling medium (26).

Abstract: A heat exchanger for a ducted fan gas turbine engine has a low temperature side and plural high temperature sides. The heat exchanger is configured such that heat is extracted from respective engine fluids flowing through the high temperature sides and is received by a portion of a bypass airflow of the engine which, on passing through the fan duct, is diverted through the low temperature side of the heat exchanger thereby cooling the engine fluids.

Abstract: A method of controlling at least a part of a start-up or re-light process of a gas turbine engine, the method comprising: controlling rotation of a low pressure compressor using a first electrical machine to increase angular velocity of the low pressure compressor; and controlling rotation of a high pressure compressor using a second electrical machine to restrict angular velocity of the high pressure compressor while the angular velocity of the low pressure compressor is increased.

Abstract: This invention relates to a superconducting electrical machine, comprising: a superconducting winding at least partially surrounded by a magnetic flux guide, wherein the magnetic flux guide includes a binder loaded with a magnetic material.

Abstract: A tail section for an aerospace vehicle is provided. The tail section comprises a rudder which is movable about an axis to generate a yawing moment on the aerospace vehicle. The tail section further comprises a thruster having, in flow series, an air intake, an electrically powered device for accelerating the air received through the intake, and an air outlet which directs the accelerated air to increase the yawing moment generated by the rudder.

Abstract: This invention relates to a superconductor device, comprising: a superconductor; a former which supports the superconductor; and, an intermediate electrical connector attached to the former for coupling the superconductor to a power source, wherein the intermediate electrical connector is connected to the superconductor via a deformable portion in the intermediate electrical connector, wherein the deformable portion allows relative movement between the superconductor and former.

Abstract: A superconducting fault current limiter comprises a superconducting element having a plurality of superconducting portions and at least one connector. Each superconducting portion has end regions and each connector is connected to the end regions of adjacent superconducting portions to electrically and thermally connect adjacent superconducting portions of the superconducting fault current limiter together. Each connector provides a local reduction in the critical current and quench current of the end regions of the superconducting portions in contact with the at least one connector. This provides a phased transition of the superconducting fault current limiter in relation to the severity of a fault current.

Abstract: This invention relates to a superconducting fault current limiter, including: an input segment of an input transformer core and an output segment of an output transformer, each segment having a first end and a second end; a length of superconductor which forms a winding around the input segment and a winding around output segment, wherein the windings are connected in series to form a closed loop; a cryostat in which the superconductor is housed; wherein each end of the input and output segments are exposed to the exterior of the cryostat.

Abstract: This invention relates to a superconducting fault current limiter, including: an input segment of an input transformer core and an output segment of an output transformer, each segment having a first end and a second end; a length of superconductor which forms a winding around the input segment and a winding around output segment, wherein the windings are connected in series to form a closed loop; a cryostat in which the superconductor is housed; wherein each end of the input and output segments are exposed to the exterior of the cryostat.

Abstract: A superconducting electrical machine includes a rotor and a stator. The stator includes a stator having a plurality of circumferentially spaced radially extending teeth and a plurality of superconducting electric coils. Each superconducting electric coil is positioned around a respective one of the teeth. A thermally conducting member surrounds and contacts the stator. A cooler is arranged to cool the thermally conducting member. A vacuum enclosure encloses the thermally conducting member, the stator and the superconducting electric coils and a pump is arranged to evacuate the vacuum enclosure. The superconducting electrical coils include magnesium diboride.

Abstract: A superconducting device comprises a vacuum chamber and means to evacuate the vacuum chamber. A base plate is provided within the vacuum chamber and first, second and third cylindrical walls extend from the base plate. The second and third cylindrical walls are arranged coaxial with the first cylindrical wall. A first chamber is defined between the first cylindrical wall and the second cylindrical wall, a second chamber is defined between the second cylindrical wall and the third cylindrical wall and a third chamber is defined within the third cylindrical wall. A superconducting wire is arranged within the second chamber and a cryogenic insulating material is arranged within the second chamber to encapsulate the superconducting wire. A material having a high specific heat capacity is arranged within the first chamber and there are means to cool the base plate.

Abstract: This invention relates to a superconducting electrical machine, comprising: a superconducting winding at least partially surrounded by a magnetic flux guide, wherein the magnetic flux guide includes a binder loaded with a magnetic material.

Abstract: This invention relates to a superconductor device, comprising: a superconductor; a former which supports the superconductor; and, an intermediate electrical connector attached to the former for coupling the superconductor to a power source, wherein the intermediate electrical connector is connected to the superconductor via a deformable portion in the intermediate electrical connector, wherein the deformable portion allows relative movement between the superconductor and former.

Abstract: An alternating current system 10 has a primary circuit 11 which forms a primary winding 18 on a core 16. A secondary winding 24 is connected with a current source 26 or, alternatively, with an impedance 60. The core 16 is threaded by a superconducting coil 20 having a current source 22. In normal use, current in the coil 20 provides a DC bias level of flux in the core 16, and the source 26 is varied to maintain substantially constant flux, thereby minimising losses in the primary circuit 11. In fault conditions, current in the coil 20 is reduced or removed to increase voltage losses across the coil 18, thereby limiting fault current. The impedance 60 can also be switched into circuit, creating further current limiting by virtue of the transformer effect of the windings 18, 24.

Abstract: A cooling arrangement for an electrical connector for a superconductor including at least one superconductor arranged in a container and the container is arranged in a vacuum chamber. A cryocooler is thermally connected to the container to cool the container and the contents of the container including the superconductor. The electrical connector extends through the vacuum chamber and the container to the at least one superconductor. The electrical connector has a thermally conducting and electrically insulating arrangement. The thermally conducting and electrically insulating arrangement comprises an electrically insulating member contacting the electrical connector. A thermally conducting member contacts the electrically insulating member and the thermally conducting member is thermally connected to the to cool the electrical connector.

Abstract: A tail section for an aerospace vehicle is provided. The tail section comprises a rudder which is movable about an axis to generate a yawing moment on the aerospace vehicle. The tail section further comprises a thruster having, in flow series, an air intake, an electrically powered device for accelerating the air received through the intake, and an air outlet which directs the accelerated air to increase the yawing moment generated by the rudder.

Abstract: A cooling arrangement for an electrical connector for a superconductor including at least one superconductor arranged in a container and the container is arranged in a vacuum chamber. A cryocooler is thermally connected to the container to cool the container and the contents of the container including the superconductor. The electrical connector extends through the vacuum chamber and the container to the at least one superconductor. The electrical connector has a thermally conducting and electrically insulating arrangement. The thermally conducting and electrically insulating arrangement comprises an electrically insulating member contacting the electrical connector. A thermally conducting member contacts the electrically insulating member and the thermally conducting member is thermally connected to the to cool the electrical connector.

Abstract: There is disclosed a homopolar machine comprising a rotor and a stator. The rotor is arranged for rotation within the stator about a central axis and comprises a pair of axially spaced-apart rotor poles formed of magnetic material and which are interconnected by a structure comprising an axially magnetised magnet. The stator comprises a pair of conductor assemblies each of which is substantially annular in form and is provided around a respective rotor pole. The proposed arrangement provides a very simple and robust machine suitable for operation at very high speeds as a generator and which produces a purely is DC output.

Abstract: A superconducting fault current limiter comprises a superconducting element having a plurality of superconducting portions and at least connector. Each superconducting portion has end regions and each connector is connected to the end regions of adjacent superconducting portions to electrically and thermally connect adjacent superconducting portions of the superconducting fault current limiter together. Each connector provides a local reduction in the critical current and quench current of the end regions of the superconducting portions in contact with the at least one connector. This provides a phased transition of the superconducting fault current limiter in relation to the severity of a fault current.

Abstract: A superconducting device comprises a vacuum chamber and means to evacuate the vacuum chamber. A base plate is provided within the vacuum chamber and first, second and third cylindrical walls extend from the base plate. The second and third cylindrical walls are arranged coaxial with the first cylindrical wall. A first chamber is defined between the first cylindrical wall and the second cylindrical wall, a second chamber is defined between the second cylindrical wall and the third cylindrical wall and a third chamber is defined within the third cylindrical wall. A superconducting wire is arranged within the second chamber and a cryogenic insulating material is arranged within the second chamber to encapsulate the superconducting wire. A material having a high specific heat capacity is arranged within the first chamber and there are means to cool the base plate.