HTS magnet quench initiation system

Patent metadata

Field	Value
Publication number	US-11469022-B2
Application number	US-201916965811-A
Country	US
Kind code	B2
Filing date	Jan 30, 2019
Priority date	Jan 31, 2018
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

A device comprising a high temperature superconductor, HTS, circuit; wherein the HTS circuit comprises: a quenchable section comprising HTS material and connected in series to other elements of the HTS circuit, the HTS material comprising a stack of HTS takes comprising at least one HTS tape; the device further comprising: a quenching system configured to quench the HTS material in the quenchable section; a quench protection system configured to detect temperature rises in the HTS circuit and, in response to detection of a temperature rise, cause the quenching system to quench the superconducting material in the quenchable section in order to dump stored magnetic energy from the HTS circuit into the quenchable section; wherein the HTS circuit is configured such that, when in use, the magnetic field on the or each HTS tape is substantially parallel to a a-b plane of the HTS tape, and the quenching system is configured to quench the HTS material by producing an additional magnetic field along the length of the or each HTS tape within the quenchable section, such that the additional magnetic field has a component perpendicular to the a-b plane of the HTS tape.

First claim

The invention claimed is:

1. A device comprising a high temperature superconductor, HTS, circuit;
wherein the HTS circuit comprises:
a quenchable section comprising HTS material and connected in series to other elements of the HTS circuit, the HTS material comprising a stack of HTS tapes comprising at least one HTS tape;
the device further comprising:
a quenching system configured to quench the HTS material in the quenchable section;
a quench protection system configured to detect conditions likely to cause a quench in the HTS circuit and, in response to detection of conditions likely to cause a quench, cause the quenching system to quench the superconducting material in the quenchable section in order to dump stored magnetic energy from the HTS circuit into the quenchable section;
wherein the HTS circuit is configured such that, when in use, the magnetic field on the or each HTS tape is substantially parallel to a a-b plane of the HTS tape, and the quenching system is configured to quench the HTS material by producing an additional magnetic field along the length of the or each HTS tape within the quenchable section, such that the additional magnetic field has a component perpendicular to the a-b plane of the HTS tape.

2. A device according to claim 1 , wherein each quenchable section has a heat capacity sufficient to cause a temperature of the quenchable section to remain below a first predetermined temperature when energy is dumped from the HTS circuit into the quenchable section, and a resistivity sufficient to cause decay of the HTS circuit's current quickly enough that the temperature of the part of the HTS circuit where the temperature rise was detected remains below a second predetermined temperature.

3. A device according to claim 1 , wherein the quenching system is configured to quench the HTS material by producing an additional magnetic field perpendicular to the a-b plane of the HTS tape.

4. A device according to claim 1 , wherein the quenching system comprises a current source and a first wire which is substantially parallel to a length of the respective HTS tape, and substantially in the a-b plane of the respective HTS tape, wherein the quenching system provides the additional magnetic field by passing current through the first wire.

5. A device cable according to claim 4 , wherein the quenching system comprises a second wire on the other side of the respective HTS tape from the first wire, the second wire being substantially parallel to the length of the respective HTS tape, and substantially in the a-b plane of the respective HTS tape, wherein the quenching system provides the additional magnetic field by passing current through the first wire in one direction, and through the second wire in the opposite direction.

6. A device according to claim 5 , wherein the quenchable section comprises a plurality of HTS tape stacks arranged with their a-b planes parallel to the local magnetic field, and wherein the quenching system comprises a wire between each pair of adjacent HTS tape stacks, wherein the quenching system is configured to provide the additional magnetic field by passing current through the wires such that, of the two wires adjacent to each HTS tape stack, one wire carries current in one direction and the other wire carries current in the opposite direction.

7. A device according to claim 6 , wherein the wires are connected in series.

8. A device according to claim 2 , wherein said first predetermined temperature is about 700 K or more preferably about 300 K.

9. A device according to claim 2 , wherein said second predetermined temperature is about 300K, more preferably about 200K, more preferably about 100K.

10. A device according to claim 1 , wherein each quenchable section further comprises a non-superconducting stabiliser.

11. A device according to claim 10 , wherein the non-superconducting stabiliser comprises a metal having a ratio of resistivity to volumetric heat capacity greater than that of copper, such as stainless steel.

12. A device according to claim 1 , wherein the HTS circuit is a field generating coil, and the quenchable section contributes towards a magnetic field of the field generating coil.

13. A device according to claim 1 , wherein the HTS circuit is a toroidal field coil of a tokamak, and the quenchable section is a section of a return limb of the toroidal field coil.

14. A device according to claim 13 , wherein each return limb of the toroidal field coil comprises a quenchable section.

15. A device according to claim 1 , wherein the HTS circuit is a poloidal field coil of a tokamak.

Assignees

• Tokamak Energy Ltd

Inventors

• Slade Robert

Classifications

• Y02E30/10

  Nuclear fusion reactors · CPC title

• H01F6/06

  Coils, e.g. winding, insulating, terminating or casing arrangements therefor · CPC title

• H01F6/02 Primary

  Quenching; Protection arrangements during quenching {(protection circuits H02H7/001)} · CPC title

• H02H7/001

  for superconducting apparatus, e.g. coils, lines, machines · CPC title

• G21B1/057

  Tokamaks · CPC title